Figure this info might interest others. It was supplied by one of my group members

Info BY: samcolt_us

Joe

Info BY: samcolt_us

Bob, let me try and shed some light on this subject. To get the quality I believe you are striving for is not nearly as difficult as you might be thinking. Let’s start at the beginning and work up to the wax job. For simplicity sake let’s classify paint jobs into two categories, lacquer and enamel finishes. For the most part lacquer is used very little nowadays and for the type of finish you require not durable enough for your project. That leaves enamel, again for simplicity’s sake we have two enamel finishes, catalyzed (pro paint job) and non-catalyzed (Krylon, Rustoleum etc) enamel. With the pro paint job let’s break this into two types of catalyzed paint jobs, solid paint (John deer green on a surface shine and durability all-in-one) or base coat/clear coat (paint for the color and clear coat for the shine and durability). Base coat/Clear coat is the easiest to apply, and will yield the most satisfaction. At the risk of getting to windy on this post I would be glad to send you the readers digest version of this discussion. The prep, primer, paint and polish is a lot easier to understand with a simple explanation of what is required in each of these steps. Don’t get caught up in flow coats (piss coat) for what you are doing this isn’t important. We use flow coat as a technique for leveling the substrates (paint) on certain types of paint jobs. An example would be a 1956 Porsche speedster I am finishing for a client, this car is the very first 56 built, and being the very first car meant that the finishing technique used back then requires I use flow coats to mimic the original finish (no polishing). The concourse clients don’t want the paint to look better than it did originally. Sorry for the labor pains but I would think this subject is on the minds of enough people that want to know how to finish their projects to look the best they can with the means available to them, a quality job that you can place your signature on is not out of reach and just might yield another level of satisfaction to your project.

JMO


Painting Environment

The painting environment is really the easiest of all aspects of painting to understand. First we need to look at how catalyzed (products with hardener) dry. Catalyzed products dry two ways, first they dry from oxidization (air dry) and secondly they dry (harden) from catalyzation (chemical reaction). For simplistic sake let’s make the baseline for this discussion be 70 degrees. This is about where most paint manufacturers start from for painting. We know from earlier discussions that one of the main purposes of reducer/thinner is to act as a vehicle to get the paint onto the surface we are painting, and then to go away. Paint manufacturers know that not all painting environments are going to be the same, so they design their products to allow for the variables (temperature). They make reducers/thinners that are from slow evaporating (warm temperature) to very fast (cold temperature) to compensate for the environment we are working in. When we mix our paint, and spray it on the panel we are evaporating roughly 50% of the reducer/thinner that we mixed in our paint, in that 8-10 inches between the gun and the surface we are painting. Depending on the air temperature and the speed of the reducer/thinner we are using we can get this 50% evaporation to be more than 50%, (faster reducer) or less than 50% (slower reducer) here’s how, Let’s say the air temperature in our shop is 50 degrees, and we use a reducer that evaporates to slow for this temperature range, let’s take a look at what would happen if we were to use this reducer. The air temperature would not be warm enough to evaporate the proper amount of reducer to maintain the 50-50 rule; therefore more than 50% of the reducer would reach the panel making the paint be very wet. What do you suppose would happen? You guessed it we would have very wet paint running, and sagging all over the place. Same example, with to fast a reducer would result in the paint being to dry and not flowing out properly. (Below our 50% rule) resulting in very dry looking paint. Don’t be discouraged by all of this ratio stuff, the reducer/thinner cans tell you what temperatures they are intended for so this makes this a very simple selection. My only reason for telling you this is so you grasp the idea of mixing paint, and the effects the solvents play towards the overall paint job. Next comes surface temperatures. When we paint we want the surface we are painting to be the same temperature as the air we are painting in, this way we take the guess work of how fast, or how slow we want our reducer to evaporate out of the equation. For the sake of discussion let’s look at a couple of examples where this isn’t the case. Let’s start with the panel we are painting being roughly 20 degrees warmer than the air temperature and see what happens. We have made a trip to our ABS store and purchased the proper reducer/thinner for the air temperature we are painting in. Our panel is much warmer (20 degrees) than the air temperature we are spraying in. We spray our paint on the surface and what do you suppose happens? The material we are applying is drying to fast when it lands on the surface to flow out, and it looks dry. Don’t worry; just keep applying paint till it shines right? Wrong, underneath this shine you are trying to apply is a bunch of substrates (paint) that is shrinking and pulling itself apart creating cracks as a result of drying to fast as a result of the overly warm surface temperature. We have all seen foods cooked on the stove do this when heated to high of a temperature (milk curdling). As with the example we worked with when trying to get rid of scratches left from sanding you will have even bigger cracks appear as a result of this overly warm panel. When you finally get this paint to look shiny like you wanted, I bet if you were to take a check of the temperature at the surface you are painting, you would find that the panel had equaled in temperature to the temperature of the paint being applied, so we gain nothing by warming the panel, the paint or the room if they are all at a different temperature. Ok so the question being asked is why do painters use heat lamps and or heat in the booth if this isn’t true? The answer is these heat sources are used AFTER the paint has been applied, and allowed to flow out, this way the panel, and the paint products are all warmed at the same rate. Look at it as speeding up what we had naturally intended to happen. Now let’s look at all of that paint buildup and see what problems we have created by applying all that paint we applied to cool that panel down. Earlier I said these products dry from air, and chemical processes. The air drying occurs from the outside in, and the chemical hardening dries from the inside out. The goal is to have both working at the same rate and here’s what happens if they don’t. If we apply our paint, and the outside dries faster than the inside (to fast a reducer) we will trap solvents in the paint which can’t escape because the outside formed a barrier (crust) hampering this evaporation from taking place. But the solvents will eventually make their way out of the paint but usually at the expense of the shine, causing a dull appearance. We can speed up, or slow down this evaporation process with the proper reducer/thinner for the temperature we are painting in. When we create a heavy buildup of paint on the surface, we are placing more solvents on the surface; with a thicker buildup to escape from. We want to avoid this problem all together. The second way paint dries is through chemical reaction (catalyzation) this process occurs from the inside out. This process will take place regardless of the air temperature. A cooler air temperature will slow down the process, and a warmer temperature will speed up the process to a certain degree, but for the most part this chemical reaction will occur regardless of what we do. (Remember the concrete example?) One of the things we can do to help promote these chemicals to dry is to get air moving through the area after the paint has setup to the point where a bug or dirt, or whatever can’t land in the paint and cause a problem, usually a couple hours after painting. We know we can speed up or slow down the evaporating process by the reducer we choose, what else can we do? We can use retarders to slow down the process in hot temperatures (summer time) and use accelerators in the winter time. Although I don’t believe the average hobbyist needs to use either the accelerator, or the retarder for the type of work you will be doing. The final point I would like to cover is the outside conditions. The effect rainy, sunny, hot and cold days has on the painting process. To a large degree I covered these areas with the choices in reducer/thinner we make. But I would like to leave you with these thoughts. If I had choices on the types of days I would paint on, I would choose rainy days. Why because Mother Nature is taking all of the airborne dust and bugs out of the air for me. My second choice and really equal to my first choice would be winter time with snow on the ground, providing I was able to keep the shop temperatures in the 60’s in this choice mother nature is covering up the dust and dirt, and bugs are no issue leaving me with nice cool temperatures. My last choice would be July/August because you have dry, dusty humid and hot conditions. If asked most painters would tell you they would rather have it cooler than warmer when painting. You get much better flow (leveling) of the paint and on and on. In the old days you could experience some issues when painting in certain conditions, but for the most part the products today have eliminated most of these issues. Last but not least, what’s the best paint to buy? The answer is the one you have the best access to through your jobber (ABS store) all of the major paint manufacturers have good products. My one piece of advice I would provide is pick the brand you want and stick with it. You will never get good at painting if you don’t become familiar with the tool (Paint Products) I know some of you think by buying paint from the local JD store that you are getting the best color match etc. This is completely incorrect, I am reasonably certain that John Deer does not have a paint factory tucked away somewhere making top secret John Deer paint. The truth is they bid out their formula to all of the manufacturers to get the best price they can. You would be better served to pick one of the paint manufacturers products and stick with it, this way for the projects you do that aren’t JD green you already have supplies on the shelf ready to go.

Good Luck


We have completed the wet sanding with (320) and now it’s time to get the project ready for paint. The first thing we want to do is remove the masking paper, and any masking tape we were using. Before I get the bucket and the soap ready (suds are ok this time) I take my blow gun, and spray in all the little cracks and crevasses that dust and dirt can be hiding (do this dry). When doing a painting project either in a garage, barn or paint booth 99% of the dirt that ends up in a paint job comes from the project that is being painted. So this means if we do an extra good job of blowing out, scrubbing and spraying our project prior to re-masking for paint, we have roughly a 99% chance of a dirt free paint job. Before we begin re-masking the project we want to once again have that blow gun blowing, and drying everything it touches. This does a couple of things for us, it obviously helps to get rid of any dirt that may have been missed, but it also gives us a dry surface for our masking tape to stick. Here we go again all masking tape is not created equally. Take a guess as to what we use? you guessed it 3m brand. I typically mask the whole car off with 1” masking tape, and then go back and tape masking paper to the 1” tape with ¾ “ in tape. Tape all seams on your masking paper, we don’t want to create a place for paint to settle, dry and then blow back out onto our paint job, besides we are going to be painting our masking paper once we start applying paint. Now that the masking process is complete, we need to do a couple of quick things before we start, the first is we want to make sure that we keep the floor wet from here on until the painting is complete. The wet floor not only keeps the dust on the floor contained, but it will also help keep the overspray from sticking to your floor. The next step is to use a degreaser on a clean cloth, (not a linen cloth) the way we do this is we wipe an area with the wet cloth, and then we wipe back over it with a dry cloth, (wax on, wax off) the reason we do it this way is because the solvent loosens and suspends any remaining dirt or silicones that may still be on the panel, if we were to just let this panel flash off (dry) these contaminates would do nothing more than settle back down on the surface, this is not want we are wanting to happen. It’s time to start mixing our Sealer, Same rules apply here, and we want to get the closest color to our top coat (paint) (light, or dark) as possible. I will start by telling you what sealers purpose is. Sealer is a barrier between the work we have already done, (scratches) and the paint. It also gives us a surface that our paint can grab a hold of, and finally it gives us a solid color surface. It covers up all of those spots that you broke out on when you were wet sanding. Some people skip this step, and for the life of me I don’t know why. Maybe they want to save the few dollars it costs to buy the material I don’t know. Sealer can be bought a couple of different ways sand able and non-sand able. We want to use the sand able. (The paint manufacturers make all of their products simple light/ dark, sand able non/sand able so all of us “C” students can use them) Before you tear up this sheet because you hear the word sanding let me explain: we are not going to sand the sealer, it simply means that we can. I want to stop for a moment and clarify my position on some of the things we have been doing, mainly bc/cc (base coat clear coat) vs. single part paint, sand able primer etc. I am making an assumption through out this whole training that most of you wont be working in a pressurized down draft paint booth. That means we have a few things working against us: experience, dirt, overspray, bugs, runs, sags, touching the paint. Do you get my point? All of the products we are using bc/cc (base coat clear coat) and sand able sealer are not intended in any way to make you think these are the only products I advocate you use. Would I paint the engine on my “4430” with base coat clear coat? No, but I could. What I am suggesting is a process that will work the best for what we have to work with. With that being said I bet if you were to ask the ABS (Auto body Supply) people what they sell the most of bc/cc or single step you would here bc/cc. Let me walk you through a real life scenario. Here you are painting your pride and joy with single part paint, and all is going well until your buddy opens the door (you know the one you invited over to witness this joyous moment) and a fly, Nat, mosquito or a number of other possibilities comes in the door with him and lands in your paint. (They always land in the most visible spot) What are you going to do yell at your buddy? That won’t remove the bug; ask me to write a piece on spot painting? That won’t help for this project. What you’re going to do is resign yourself to the fact that you have a bug in your paint, on your hood, and besides that (barring anything else going wrong runs, sags etc.) it looks pretty good. Sure we can get the tweezers out and start digging the bug out, by now he is probably trying to swim his way out of the paint leaving bug parts behind. What I have been doing is leveling the playing field and the choices I have been making accomplish this. There is a time, and a place for both of these products, one is not better than another, it’s just that base coat clear coat gives us the most opportunity (more chances to fix the problem) to have the project turn out as we had hoped, that’s all. Ok, down from my soap box. Now that we have our sealer mixed (All of these catalyzed products have to set after mixing for a period of time before they can be applied) ask your new best buddy at the ABS store for the product sheet (instruction sheet) for all of the products you will be applying. These sheets tell you air pressure, viscosity and a whole bunch of other stuff as well. These are the perfect cheat sheet for all of us “C” students. Now it’s time for the tack cloth, nothing tricky here just wipe all of the surfaces to be painted with it, don’t throw it away, we may need it again before we are done. Next we paint, I promise


Prepping the surface, as I have said in the past posts I am making the assumption that we have panel prepping completed. I think for the sake of clarification after we finish these posts I will do a post on making sure the panel is prepped properly for finishing (plastic laid down properly and sanded level). We’ll see if there is any interest. Ok here we go for the sake of understanding I am going to use several different scenarios to try and paint the broadest picture (pun intended). First let’s start with a restoration of a 70 big block challenger (because I just did one and I can remember it) Although I prefer to metal finish the panels, for the sake of this discussion we’ll say we have some places we used plastic (Bondo) and we need to now get this car prepped for paint. So we have carved some scratches in the metal and in the plastic and we want to make sure these scratches don’t come back to haunt us. This should actually be covered in the prepping the panels post that I was kicking around doing after all of this but we’ll touch on it here for the sake of going foreword. I have read some of the posts about laying the primer on thick and or wet so it “fills” these scratches and some other ideas mentioned with good intentions. The truth is this isn’t what primer is meant to do, and it won’t do it very well. Let me explain, when you spray any product on a solid panel with pressure the air hits the panel and then blows back up away from the panel leaving most of the product on the panel but there is still the air pressure to deal with, we call it overspray. We need the air pressure to atomize the solids we want to lay down primer/paint etc, but then we would like this surplus of air to just go away. But it don’t, since the only real purpose thinner/reducer has in this whole process is to act as a vehicle to get the product on the panel and then evaporate, what happens is the air being bounced off of the panel meets the product going to the panel and what we have is a case of the thinner/reducer flashing off, in other words drying. Ever been washing your car at the self serve car wash and get hit by this blowback? You get the point. The paint manufacturers take all of this into consideration when producing their products. And it’s because of this blow back (overspray) that the gravity guns were invented (HVLP) high volume low pressure. I started using gravity guns back in the eighties before they were popular (Optima E 80 hard to beat German products) and I have to tell you it was one of those milestones in this industry. The challenge was that the manufacturers had no real data on how to put the product on under those conditions and we really had to learn the dynamics of these guns because we were doing a lot of candy and pearl paint jobs that were not forgiving. The manufacturers were coming to us for information on how this was all working. Anyway so what does all of this mean to the scratches in the plastic? It means that these primers are bridging over the scratch and it absolutely will come back to haunt you. So how do we prevent this without me going off on some tangent? (Sorry) the way we prevent this is we sand the scratches out, with a block sander using the cross hatch method we just learned about. Think about this for a minute the sooner you start spraying primer/surfacer or whatever on your project the sooner you need to start allowing time for them to dry so you can do what? Oh ya sand some more and more all the way back down to the scratch just so we could hope to have a little good luck and possibly get some of this primer in the scratch. Sounds like a lot of work for nothing but failure. What will happen by sanding these scratches out is we can prevent all of the above from taking place and insure we have the quality job we are after. Each grit of sandpaper leaves scratches; these scratches get smaller as the numbers on the paper get bigger. As you get more familiar with all of this you will be able to look at a panel and actually know what grit the project was last sanded with 36,80,180, etc. Our goal is to get our challenger (all of it) to 180 grit. Here is a tip, dust a guide coat with a spray can of primer I happen to use Krylon but use whatever, I use black. Dust this over the plastic you just sanded, after drying sand this “guide coat,” those scratches will either look like a road map or all of the primer will sand off, if it all sands off this means these scratches were being removed by the grit we were using, in this case 180 and the surface is completely flat. That’s a good thing. We are now ready to apply surfacer/primer. From here on I will be talking about primer surfacers not really primers. Primer surfacers are a tremendous advance over conventional solvent based processes in that they provide not only a filler, but also a synthetic surface for our paint to set on, when I say filler I don’t mean to fill the scratch, I am talking about filling the low spots, so we can sand (with our 180 dry) down the high spots making for a very straight panel. Believe me when I tell that you will be able to see your sanding marks after a little experience, and they should all be going the direction of your cross hatch sanding. Are you beginning to understand that these scratches are actually a good thing? They are showing us what the panel is doing and we would be flying blind without them. Let me illustrate this for you. We are working on that John Deer 110 hood and we want to make sure the panel is flat and free from any unwanted scratches. We have sprayed one coat of surfacer primer on the hood and after drying we are ready to hit it with (180 dry) we are sanding with our cross hatch technique, after a couple of minutes we stop and look at our scratches. All of them are going in the direction of our sanding, but in this area in the middle of the hood the scratches stop, and then pick up again roughly 6 inches away from where they stopped. What do you think this means? It means that this spot is still low and we need to continue sanding the WHOLE surface not the area untouched. One of two things will take place, the gap in the scratches will either close, or you will breakout which means a spot will appear that you have sanded all of the primer filler off of. Since our goal has always been to put the least amount of products on possible the lack of scratches and the breakout tells us we have sanded that hood the most we could with that coat and now we need to spray one more coat on the whole hood. Ok, we are back on our 110 hood and we start the cross hatch sanding again. We have sanded the entire hood again with our 180 file and after checking our area where we were originally low, we can see that our scratches now continue all the way through the strokes. This tells us that we have a nice flat surface, but I want you to now continue sanding until you break through again. The reason for this is we want to now remove any excess material that we don’t need. If you breakthrough at 2:00 then work more towards the 6:00 area. Once this is completed at (180) move on to another panel, and that panel is now completed. Back to the challenger, we are going to continue this process across every panel on the car. A quick note here about the above work, now that you know what we are doing and how we are doing it I will tell you to use time to your advantage. The more product that is drying the more you are getting done. Example on the challenger and the 110 hood, I would have sprayed two coats on all of the plastic repairs, spraying past the repair 3-4 inches as soon as I completed the plastic work. I will cover this in the panel prepping section if anybody is interested. Also I’m guessing most of you have to try and find the time to work on your projects, and your shops get cold when your not there to stoke the fire. That’s ok, before you shut the lights out for the night spray a coat of surfacer primer on the areas that are ready and these can be drying/curing until the next time. Let’s take a moment and talk about the drying/curing process. These products we are using are catalysed (hardner) which means they not only flash off (dry) but they also cure. It’s this curing that is going to make it ok for that shop to get cold if it has to. Liken this process to pouring concrete in the winter, it dries slower on the surface, but it’s still curing underneath. Ok, the guy with the challenger is getting all excited to see his baby dressed in plum crazy, so we better continue on. We have all of the surfaces at (180) we have sanded off the excess material with some breakouts what’s next?, how about we spray the entire car for the final time and get it ready for some paint. I know what you are thinking, he had me remove any excess material so I could do what, add another coat. That’s right, those coats were to get the car straight, wet sanding on those coats would undo all of that. We need a new coat so we can begin the wet sanding process.


Now we are ready to begin the wet sanding stage of our project. First, I am very serious about the type of paper we use, 3m automotive paper that’s all we have in our cabinet. For the critics out their who might be reading over your shoulder here is my thought, I am using this paper because I know some of you out there live in areas where your access to an ABS store (Auto Body Supply) may not be possible. I also know many of you have access to an ABS store but have stayed away because all of this was over your head and you don’t want to appear ignorant, understood. The truth is I have been to a few ABS stores over the years and I can say with certainty that I have never been treated in any way that would cause me to think this would happen to you. In fact I will tell you now that you will make some lasting friendships with these people who share a common passion with each of you, and they will always be willing to coach you, teach you and support your efforts. The 3m paper can be found about anywhere you go, and I feel you will have the best chance of locating a source for this paper. There are a few things we need to do before we start wet sanding. We need a bucket, a few sanding blocks and some dish soap, (not the kind of dish soap that will leave your hands young looking) no moisturizers in the soap and not extra bubbly. (Whatever you do avoid using Ivory liquid; you will have suds coming out for months). For some reason I think I use dawn, I know its gold in color anyway. We want to put water in the bucket before we put the soap in the bucket, we are trying to keep the suds to a minimum, don’t worry, it will emulsify. The next thing we want to do is prep our sandpaper, if we are starting with full sheets we will need to cut them into half sheets and then fold them in half in preparation to be used on the sanding block. Go ahead and prepare 5 or 6 half sheets and throw them in the bucket of water, we will want to let them soak until they are limp. (5-6 minutes usually) We never want to use paper that hasn’t been broke down prior to using. The soap in the water serves several purposes, it helps to lubricate the sand paper (keep it clean) and also keeps the oil from our skin from getting embedded in our primer surfacer. I want to talk about the guide coat that I mentioned earlier. Now that we are going to wet sand, guess what we are going to loose, those scratch marks that had been helping us all this time. Now we will be on our own so we may want to spray a guide coat to help hold our hand. I say may want to because I am confident that after you master this sanding thing this guide coat will become optional. For at least the first couple of projects you do I think a guide coat will be a great training aid so let me explain it to you, and teach you how to use it. First of all when you buy your substrates (primer sealer) you want to buy the color that is the closet in color to your top coat (paint color). This is very simple because they only come in dark or light. Whichever you are using you want the guide coat to be the opposite. We are not trying to paint the car with this coat but rather coat the surface to roughly 60% opacity (Dust it so you see 60% primer from the can and 40% of the primer surfacer) to do this we are going to hold the can 10-12” away from the surface and start spraying. We will be spraying this primer on dry because all we want is for this coat to “guide” us as we wet sand the surfaces. Go ahead and go different directions etc, our goal is uniformity here. I usually do the guide coat first, and then prep the sand paper and get the water while the guide coat is drying. Now we are ready to begin sanding the panels, and how do you suppose we are going to do this? You guessed it; we are going to sand all- of- the guide coat off. Same rules apply, cross hatching patterns for the technique. You will probably notice a great deal of resistance from the sanding block as you start sanding, this is normal it just means you did a good job getting the panel level. One of the most common mistakes I see being made with the beginners starting out is they use a piece of sand paper for to long. I spoke early-on about your hands being your best tool, well throughout these different stages your hands have been giving you feedback as to what was going on. They have been telling you if the plastic you sanded is too high, or too low, they have been telling you if one area felt rougher than another and they have been telling you when the sandpaper was used up. You were probably to busy making more work of this than needed, and didn’t pay any attention. Sand paper doesn’t go until you are tired and want to stop for a break, sandpaper has a yield just like everything else and most people exceed the effort = achievement rule by quite a bit. The block and the sandpaper are the tool, let them do the work. Let’s walk you through this: we are sanding the hood of this challenger starting with new paper and no sanding has been done yet. Divide the hood in the middle and let’s start. I would sand the whole side just trying to break through the top layer (crust) with the first side of my paper, (the underneath portion sands easier after you get through that top crust, by the way this is true with each step from plastic, to clear coat) if the paper was telling me it was still usable I would start to focus my sanding on removal of the guide coat. I want to draw an analogy here that I think might be helpful. Most of you have drilled a 3/8 inch hole in a piece of ¼ steel before right? If I were to blindfold you while you were drilling the hole and ask you tell me where the bit was in relation to boring the hole could you tell me? Of course you could when it first starts getting a hole started you would know because the bit stopped trying to walk, as the bit penetrated deeper you would be able to tell by the twisting on the drill right, and finally you would know in advance to get ready to let go of the trigger before the bit hangs up and twists your arm off because you are getting ready to break through agreed? Your hands were telling you all of this. And let me ask one final question, how long would it take you know if the bit was sharp or dull? Same rules apply to doing body/paint work (a blind man can do body work, he just can’t paint) Ok, so the paper gives up, we turn it over and we start back on our side of the hood again. Where do we start? On the opposite end from where we started with the last sharp piece of paper. Let me explain: if you keep starting all of your fresh paper out in the same spot where have you sanded the most product off? You guessed it, in that spot so vary you’re starting points on this piece. Oh an important point of clarification, now that the sanding scratches are gone we no longer care about the direction of your sanding strokes (6:00- 12:00) we are working from the guide coat now, but we still want to use our same cross hatch technique. Have you noticed we don’t have a hose running water all over the shop? We don’t need it, we need to use one of those extra sanding blocks (without paper) turned at an angle to be used as a squeegee. Back to our 110 hood standing perpendicular to the plane of the hood (the hoods 6:00 and 12:00 are at your 3:00 and 9:00) in other words beside it. Place the block on edge and draw it from right to left at an angle and work the block towards you removing the unwanted material. By using this technique we don’t wash this stuff all over the engine bay and the shop. This will prove to be very important in the next step which is painting.









Body and Paint Procedures Manual for the Do It Yourselfer

"Believe in the best... have a goal for the best, never be satisfied with less than your best, try your best, and in the long run things will turn out for the best."
Henry Ford (1863-1947) American industrialist





















TABLE OF CONTENTS

USING THIS MANUAL
Purpose

Introduction

1. Preparing surfaces for bodywork
1. A. Applying and working with plastics

2. Paint Gun Techniques
2. A. What a Paint Gun Does
2. B. Types of Paint Guns
2. C. Adjusting Paint Guns
2. D. Proper Gun Techniques
2. E. Spray Gun Troubleshooting

3. Primer/Fillers
3. A. Types of Primers-Fillers
3. B. Applying Primer-Fillers
3. C. Sanding Primer-Fillers

4. Preparing Project for Sealer
4. A. Taping and Masking
4. B. De-greasing panels

5. Purpose of Sealer
5. Applying Sealer

6. Painting Your Project
6. A. Types of Paint
6. B. Preparing for Paint
6. C. Types of Paint Guns
6. D. How to Use your Paint Gun
6. E. Painting Your Project
6. F. Gun Cleaning

7. Sanding and Polishing Your New Paint


USING THIS MANUAL

This manual was prepared for use by the do it yourselfer. Organized along key structures, this manual is intended to teach and help form the foundation for which you can build on through your experiences doing body/paint work.


Purpose

This manual explains how you the do it yourselfer, can become confident in your ability to complete the body and paint portion of your project. My goal is to help and support your efforts by providing you an outline from which you can work.


1. Preparing surfaces for bodywork
Applying and Working with Plastics
Bodywork- The bodywork is the single most critical aspect of the paint job and is the foundation of a truly quality paint job. If this isn't perfect, the paint can’t be. Paint will not hide flaws, (You can’t paint it straight) it will only magnify them. With the bodywork phase, we want the surfaces to be perfectly smooth with all contours exactly as they should be. The mistake I see most commonly made with regards to the use of plastics with beginners is the size of the area they think they need to work with. I have seen guys spread plastic on a repair the size of a quarter, thinking this was acceptable because it was just a small dent. As an exercise to show the effects a small dent has on a panel I want you to take a firm pillow and push your finger into the middle of the pillow, look and see how much of the pillow was effected, if this was a panel, roughly 6-8 inches of metal was drawn in, but the actual dent was only the size of a quarter. Often times in the case where multiple areas need leveling on a panel it is best to coat the whole surface. When working with fiberglass. We want to use it as a means to create a flat surface. When using plastic we want to rough the area with 36 grit from our grinding disk. Apply plastic to only the area that is low. Don't try to block out this first coat, this coat is just a base for the last coat. Just apply a nice coat of filler. We want to just cut this coat, we are not trying to finish this coat. Cut this coat with 36. If you are just working a small area 6-10 inches in diameter 80 grit may be sufficient. Remember we want to use the highest number possible for any given area to be worked. In other words, if you can cut it fast with only 80 then do it. But I would say that this would be limited to an area that is no larger than about 8 inches. If you happen to have a few high spots, see if you can tap them down. (Remember, you can’t fill a high spot) NOTE ABOUT HIGH SPOTS, TO THE BEGINNER HIGH SPOTS CAN FOOL YOU INTO THINKING THE AREA AROUND THE HIGH SPOT IS LOW.
If you have a few low spots add a bit more filler to only those spots. Re-cut these last low spots you have just filled with the same grit you have been using (most likely 36). If you now have a surface that one skim coat will fill, then apply it. If you don't, work with it a bit more, but never add a little here or there and think you will finish it without a skim coat. This skim coat is very important, you want it to extend over the complete area, maybe as much as 3 inches past the plastic that you have applied to "rough" it out. This is well past the damage you have been working. Do not use anything that doesn’t mix with a hardener. No, “Spot putty” in a tube, only polyester putties or fillers. If it uses a hardener, it cures to a hard film. The “spot putties” stay soft and can become even softer when the solvent from the primer coats it. You now run a block, or long board, over this skim coat with a little bit coarser paper than you plan on finishing with to “cut” the resin that has surfaced in the filler. I usually just use the 36 or 40 or whatever I have been using on the "rough" work. Be careful not to cut much off, you want to just take the very top; don't really sand anything but the top resin. Now finish sanding with your long-board or block or whatever your using with the finer paper, like (80) on a large area or (120) on that small 8" sized area. Block it out to perfection with a nice feather edge to the surrounding metal. I can't stress enough; the trick is to know when just one last skim coat will do the job. And apply it completely over the surface. If you only have one little low spot in the middle, don’t just fill it, and skim the entire area. You have to have one last skim coat over the entire thing every time. If you get in the habit of this you will do it over and over on every dent you repair and find that you can do just about any dent with just two applications. As you sand the filler let the board or block you are using run over the surrounding metal. If you only work on the filler you will sand it too low. You need to keep it as high as the surrounding metal, so use the metal as sort of a straight edge that you run the block or board off of. Don’t worry if you cut through this skim coat here and there. In fact, you will most likely cut through. The point of that last skim coat is that after you add it, you don't add any more filler. That last skim coat is just that, the last filler you add. If you hit a little filler below, or metal, that is normal and ok. The only thing you are looking for at this point is if the panel is flat. The filler skim coat is serving no other purpose than to finish your filler work. The last skim coat should be left to cure a long time. Where you may jump on filler and sand it as soon as it is hard, the skim coat should be allowed to cure for at least an hour or more. If you can of course, the benefits of this procedure is that the plastic will have ample time to dry and cure before sanding. When working with fiberglass surfaces or metal surfaces that have multiple little areas of repair close to each other often it is best to coat the whole surface with plastic as outlined above, and then cut the plastic down with your sand paper.

2. PAINT GUN TECHNIQUES
What a Paint Gun Does
A spray-gun's mission is to atomize refinishing material--it takes paint droplets and divides them into thousands of tiny particles. At the heart of this is the nozzle set, which consists of the air cap, the fluid tip and the paint needle, "When the gun is triggered slightly, it opens the air valve, and the spray-gun acts as a blowgun. As the trigger is retracted further, it unseats the needle in the fluid tip and material begins to flow. On a gravity gun, the quantity of fluid leaving the gun is controlled by the viscosity of the material, the size of the fluid tip and the needle adjustment. Normally, this adjustment should be nearly fully open, thus allowing full trigger control.

Types of Paint Guns
For the discussion here there are two types of hand-held spray-guns: gravity and siphon. The siphon-feed design has been around for a very long time. It is the most popular spray-gun configuration. But the gravity gun has quickly developed a strong following. A growing number of painters have quickly migrated to the advantages of gravity guns. Some of the main advantages of gravity guns are, the air supply isn't used to pull the fluid to the cap, so it requires lower pressure to do the same job as its siphon-fed counterpart. "Most manufacturers produce these variations in both HVLP and conventional versions.
Adjusting Paint Guns
Working hand-in-hand with atomization is proper gun setup. spray-gun set up should be the best combination of the proper nozzle choice, pressure setting, fluid flow and fan width, Most spray-guns allow the user to adjust fluid flow and spray pattern, The fan control is used to control the spray pattern width. As a rule, most painters want to use as wide a fan as possible, but as the fan widens, the amount of material distributed decreases.
"For conventional guns, (Siphon fed) the general rule of thumb is to use the lowest pressure that will provide the best atomization and spray pattern."

Proper Gun Techniques
After setting your equipment properly, it's-as they say-all in the wrist. Even with the spray equipment and the optimum gun settings, a poor technique can ruin a paint job. An improper spraying technique will result in uneven coatings, mottling, dry spots, runs and orange peel.
To improve finish quality, painters must control:
* The distance from the spray-gun to the target;
* spray pattern overlap;
* triggering;
* working speed;
* Spray-gun angle (heeling, toeing and fanning).
Painters' spray techniques are also overwhelmingly dependent on constant visual feedback: They have to watch what they are doing. Be sure to apply the paint evenly-pass the gun perpendicular to the surface at a constant speed. Slowing the rate of the pass will put more material on the panel, and increasing speed will decrease the amount of material applied. Use the speed to regulate your material, and watch the panel very closely to see if you are "wetting" the surface. Each pass of the spray-gun should overlap the previous one by about 50 percent. Watch the material closely to see how it is being laid down.
Never go over the same surface twice. It is always better to let the material flash and then correct the problem on the following coat. Depending on your selection of reducer and hardener, the material will flow to some extent after it has been applied.
Don't be shy about applying the coatings. If you are afraid to "wet" the panel, you will produce dry-looking paint jobs with excess orange peel. Remember that runs in the clear coat are usually repairable after they have cured.
Follow directions to prevent such mishaps as paint application failures and runs are generally the result of insufficient flash times. If the successive coats are landing on material that hasn't had the chance to evaporate its solvent, you'll end up with a run. It is better to error on the side of caution. If you are in doubt regarding flash time whether it's because of low or uneven temperatures on the surface of the project, allow an extra few minutes to let the solvent evaporate.
If debris or insects land in the finish, a steady hand and a pair of tweezers can often save the job. The topcoat will flow out to some extent if the material hasn't cured; leaving you with an imperfection that can be sanded and polished to perfection. In more severe cases, you will have to re-spray the panel. When in doubt, wait for the finish to dry.
Practice painting on a piece of masking paper or card board. Hold the spray gun 8-10 inches away and start spraying while the gun is moving. Stop spraying before you stop moving the gun. Smooth sweeping strokes, keeping an even distance from the surface, and light coats are important.
Although these recommendations target beginners, the beginning painter should also remember that practice is the best teacher, and you should begin enhancing you skills by applying primer-surfacer because that coating will usually be sanded. Remember to review the safety precautions noted on the MSDS, and above all, relax and have fun.

If the gun is not held perpendicular to the surface, one side of the spray pattern will be wet with a tendency to run and the other side will be rough and dry.


The gun should be properly adjusted each time you spray. A -*test*-('") pattern should always be sprayed on a piece of cardboard before beginning to paint. The normal pattern for a spray gun will be fan shaped. To begin the actual application procedure, hold the spray gun approximately 8 inches from the surface you will be painting. This distance may vary somewhat depending upon whether you are using a HVLP system or a pressure spray gun. The spray gun should be far enough away so the paint does not run or sag when applied and close enough to lay on a wet coat. To prevent the paint from being uneven, it is imperative that the gun be held exactly perpendicular to the surface. If it is tilted the paint will be heavier on one side and lighter on the other. See above. The spray gun should then be moved parallel to the surface only the distance you can comfortably move your entire arm while keeping the movement exactly parallel.
The paint spray gun must be moved parallel to the surface. If the gun is moved in an arc, the spray pattern will be thick in some spots and thin in others.

If the gun is moved in an arc the material will be applied heavier in some places and lighter in others. You should squeeze the trigger of the gun just prior to beginning the paint stroke and release it just before it is completed. You then should move up or down approximately 50% of the fan width and begin the next pass. You must overlap the passes to achieve an even build-up. Each pass of the gun will usually apply the paint more thick in the middle with a tapering off on each end. Remember our definition of a cross-coat, one pass north and south followed by a pass east and west.






Spray Gun Troubleshooting
* Spitting or paint bubbling in the cup is caused by atomized air getting into the fluid passage. This is usually the result of insufficient tightening of the fluid tip or a loose air cap. It can also be caused by damage between the flat surface of the fluid tip and the fluid tip spindle.
* Spray pattern fluttering can be caused by too little paint in the cup, a loose fluid tip or a damaged needle seal.
* A "sickle" or quarter-moon pattern is usually caused by partially or completely clogged air horn passage.
* Too much air pressure may cause a split pattern. Remedy this by increasing the fluid flow and narrowing the fan pattern.
* A teardrop pattern is the result of dried material on the outside of the fluid tip and a bent needle or fluid tip




3. Primer/Fillers
Types of Primer-Fillers
There are two types of Primers, Lacquer, and Urethane. Lacquer primers found in spray cans and purchased from an ABS (Auto Body Supply) stores are rarely used today. Since lacquer primer never cures and is made up of talc, it absorbs the solvent used in your topcoat (paint) causing lose of gloss to the topcoats followed by paint swelling and sand scratches re-appearing.
Urethane Primer contains more solids than lacquer primer and you will use about half the amount to do the same job. Urethane and Epoxy primers are activated and go through a thermosetting stage. Thermosetting (Hardening) in this case the urethane primer is activated and will become setup. It is designed to become a strong, durable, chemical resistant coating. The benefits of this are that the paint will not lose gloss, shrink or swell as easily. The solvents that are used in the Basecoat system are very strong. You must have an activated and cured undercoat in order for it to resist and repel the solvent from penetrating into it. Make sure the primer has dried completely before sanding or scuffing.

Applying Primer-Fillers
Before spraying, always run a clean rag with your degreasing solvent over the surface to remove any grease, then a tack rag to remove any dirt or lint. With primer in the gun, -*test*-('") your spray pattern on a stiff piece of cardboard and adjust as necessary. The gun should be held from between 8" to 10" from the surface being painted. Overlapping 50% on each pass. Apply primer as a wet coat. Experiment here: too close will be very wet and run; too far will be too dry and dusty looking. Apply two or three coats to the areas that have been worked with plastic allowing sufficient flash time between coats. After sanding has been completed to the areas that have been worked with plastic, a complete coat can be applied to all surfaces if desired.

Sanding Primer-Fillers
Begin sanding with 120 or 180 grit dry using the cross hatch method for your sanding technique. After sanding the entire project to 180, wet sanding to 320 or 400 can begin (It is never recommended to “jump” around the project with different grits of sand paper always complete one grit before moving to the next)

4. Preparing Project for Sealer
Taping and Masking
Mask areas not to be painted with good quality masking tape. Protect large areas with masking paper. Don't use newspaper, it tears easily, and does not prevent solvents from penetrating the paper. Tape all joints and folds to prevent paint from collecting later making their way into your paint job.







De-greasing panels
Start prepping the vehicle by wiping it down with a wax, grease, and silicon remover. This cleaner is available at auto body suppliers and it is applied by wiping the vehicle's body with a saturated cloth, and then wiping dry with a different clean cloth.
The basic idea behind these cleaners is simple; they are designed to lift the contaminant up off the surface long enough for you to wipe it away. The surface must stay wet and hold those contaminants up in the cleaner for you to wipe off with a clean/dry rag. This is a mistake most make, they let it dry and the contaminant ends up laying right back on the surface. First of all let’s clear up a few things; Lacquer thinner, acetone and enamel or urethane reducers are not surface cleaners. Lacquer thinner evaporates too fast and doesn’t give you time to wipe it off wet. It is also much too strong a solvent for most cleaning and can get under the edges of sand through and soften substrates. Enamel and urethane reducers often have resins and other components in them that are designed to be added to the product they were intended to be used with. Use the products recommended by the manufacture of the paint system you are using. (We spray it out of a spray bottle). You spray the panel and then wipe it off. I like to have lots of clean rags when I am doing paint work. Clean rags are one of the most important items you can have in a shop. We prefer the disposable rag. You can get a box of “rags” for a pretty fair price and just throw them away when done. You always have nice clean rags. They are not “just” paper towels, Go to your paint store and get the real thing. There are many different kinds, from cheap wipes similar to your kitchen “paper towels” to lint free towels for final wiping. So let’s go over exactly how you use it. As mentioned earlier, you need to keep it wet prior to wiping it off. The best way to do this is keeping your cleaning area down to a manageable size. I usually wipe no more than a half a panel at a time. About six square feet is all you can do without problems of it drying to fast, and even then you have to keep moving pretty fast. You just don’t want it to dry, if you do, you have wasted your time. You haven’t done what you intended to do. When should you wipe the surface? Well first of all, before you sand. If you don’t wipe the surface before you sand you will not sand off the contaminants, you will sand them into the surface. So a good cleaning before sanding is recommended. If the surface is really dirty, clean it a few times changing to clean rags every time. Remember, you want to wipe off the contaminants, so if you use the same rags on the subsequent wipes you can leave the contaminants you wiped off on the first wipe! Wiping before applying primer or paint of course is also recommended. Be sure that any remainder has flashed off (evaporated) before applying your primer or paint. You don’t want any of the cleaner to be trapped under your primer or paint! Have a few rags ready to go folded in fourths. Put the rag over the opening on the can of surface cleaner and give the can a “slosh” getting the rag wet, not too wet but wet. You don’t need to have it dripping all over the floor, but it should be good and wet. Get in the habit of wiping things down like you are painting it. Use a back and forth pattern with an over lap being sure to wet every square inch. The entire area should be shiny wet, then switch to a clean dry rag and wipe it dry using the same “get every inch” procedure. If you feel it dried before you could get it off, repeat the cleaning. “YOU CAN NEVER GET A CAR TOO CLEAN.

5. Purpose of Sealer
The purpose of Sealer is to provide a barrier coat between the plastic/primer and the paint. Also it creates a single color under our paint, and finally it gives our paint something to grab a hold of. We want to get the closest color to our top coat (paint) (light, or dark) as possible. Sealer can be bought a couple of different ways sand able and non-sand able. The sand able allows us to knock down any nibs that might develop prior to top coating.

Applying Sealer
Apply sealer the same way you apply paint section 8

6. Painting Your Project
Types of Paint
PAINTS You have a choice of the type of topcoat paint along with a large number of brand names. Enamel is a paint that is commonly used. These paints are sprayed over epoxy primer after being thinned to proper consistency using enamel reducers. A light, mist coat is first sprayed on and allowed to dry for a few minutes until it is tacky to the touch (Called a tach Coat). This is then followed by a full coat of enamel. One full coat may be sufficient or another may be sprayed if desired. The use of enamel is not as popular as it was in the past. A second type of topcoat paint is acrylic lacquer. This paint has a low solid content that makes it more difficult to apply. Acrylic lacquer should be thinned using the proper thinner and then a very light tack coat applied. An additional 4-5 cross coats of paint will then have to be applied allowing about 30 minutes drying time between coats. (By the way, a cross-coat is defined as moving the spray gun north and south followed by east and west: one cross coat). Polyurethane paint is probably the most popular choice for a topcoat today. It is very durable and provides a high gloss finish. It is also chemically resistant. These paints have a high solid content and they cure very slowly which means they continue to flow out for a long period of time. This flowing out process forms a very flat surface that gives the surface a high gloss look. Polyurethane enamels are mixed with a catalyst prior to use. They are then reduced to proper viscosity for spraying. A very light tack coat is first applied followed by one or two full coats. One problem inherent in polyurethanes is the thickness of the film applied. If the paint is applied too thick it may tend to crack over a period of time. No matter which paint you choose a few fundamentals apply. First of all, the paint needs to be properly mixed. That means shaking the paint on a paint shaker within one week of application. After shaking the paint it should then be thoroughly stirred just prior to use. Secondly, the surfaces should be wiped down with a paint cleaning solvent using a clean rag. Then a tack rag should be used to remove any dust. Thirdly, the paint should be properly thinned by following the manufacturer’s directions. A viscosity cup can be used for the thinning procedure. These are small cups with a hole in the bottom. The cup is filled with paint and then the viscosity is determined by the amount of time, in seconds, required for the paint to flow through the hole until it begins to drip. The next step is to strain the paint through a mesh paint strainer. This should be done prior to placing the paint into the spray cup. If you are using a polyurethane paint, you should strain the paint prior to mixing the catalyst. Mixing the catalyst in polyurethane paints should be done in accordance with the directions from the manufacturer. Usually, you should let the catalyst react with the base paint for at least 20 minutes prior to spraying. Once you have mixed the paint you will have approximately 5 hours before the chemical cross linking begins and the mixture begins to thicken. With that in mind, only mix the amount of paint you will need for the job. Other chemicals in addition to reducers that you may encounter are retarders and accelerators. A paint retarder very simply is a solvent that slows the drying time of the paint. It is added in proportion to the directions on the paint can. Retarders are generally used in high temperature or high humidity conditions. Accelerators have the opposite affect. They speed up the drying time. Accelerators may be required to help the drying process in cool temperatures.

Whichever type of paint and brand you choose, you want to use that company’s whole system. From primer to topcoat stay with the products recommended by the manufacturer.

Preparing for Paint
g aBefore we begin applying any product to the project we want to first ground the project to the earth. If the project is already on jack stands this will work. If not, we will need to place a chain around something metal on the project and let this chain touch the ground. With all of the sanding that has been taking place, we have built-up a high concentration of static electricity. tIf we do nothing to remove this static, our project will act like a great big magnet collecting all the dust that might be in the air. Next we want to clean the entire area around the area we will be painting. Wet the floor to contain any dirt that may have been missed and also trap overspray that will fall to the ground as we are painting. (This process should be followed when sealing the project as well).

Painting Your Project
The first coat of any paint job always goes on light so it will dry fast and provides a sticky surface for the subsequent coats. Overlap each line of paint by about 50%. Evenness of the paint is what you want and it is a function of the proper paint mix and gun spray pattern, perfect perpendicularity of the gun to the surface being painted and maintaining exact consistency of speed at which you draw the gun across the surface you are painting. Paint the edges of the project first. Edges often do not receive an adequate amount of paint. Painting them first will solve this problem. If at all possible, paint on a flat surface. Of course, that is not always possible. Paint will sag or run much more easily on a vertical surface. Spraying in corners and around corners presents a problem. Practice in areas such as this to establish the proper technique. As a general rule, spray the corner first whether it is inside or outside then you can blend the paint in with subsequent strokes. After this “cutting in” is completed we want to begin by applying paint to the tallest surface first. If we are painting a car we want to start on the roof and work our way down the roof pillars to the hood. Our goal in any painting project is to have the overspray landing on the areas we have not yet painted. Paint the vertical surfaces next working from top to bottom, left to right. Repeat this process on the other side as well. We are always trying to paint next to wet paint so we don’t develop dry spots. Proper reducers go along way to help prevent this from happening. Consult with the people at the ABS store when purchasing your products as to which reducers will be best for the conditions you are planning on painting in. Allow ample time between coats to let the reducers flash off; refer to manufacturers recommendation on product sheet. Apply only the amount of paint required to have all paint surfaces colored, any more than this is nothing more than buildup. While the skill and knowledge of the person applying the paint is important, preparation is the key to a good-looking paint job.

Gun Cleaning
Gun cleaning should be done as soon as possible after spraying. The longer you leave the paint materials in the gun the more difficult it will be to clean.
Be sure to wear the appropriate protection while handling solvents. Gloves, safety glasses and breath protection are highly recommended.
Remove the cup, air cap, fluid tip and needle. As with any gun you need to be VERY careful when removing the fluid tip. If the wrench slips off it's grip and nicks the tip the gun will not spray properly even with just a slight nick on the tip. With a Sata that could cost you over $150 so hold the gun (any gun) and the wrench securely when you loosen or tighten the fluid tip.
Don't soak the gun body of any gun in thinner. Use lacquer thinner in a squeeze bottle and a small bowl or cup. Take each part and use the proper size brush to break loose the paint from the walls of the parts then rinse with a shot of the thinner over the cup. You should only need a couple ounces of thinner to do a good job. Wipe the parts with paper towels then lay them on a towel to dry before reassembly. Install the fluid tip on the body before you install the needle, if you install the needle first you could tighten the adjustment too much and then when the fluid tip is tightened you could bend the needle or damage the fluid tip. Lubricating the needle will help the action of the trigger remain smooth. If you use a decent gun cleaning kit you can push a probe through the air cap holes to help keep them clean. Wipe out the cup with paper towels before you use thinner to finish the cleaning it and be sure to clean the pipe between the cup and the gun with the proper size brush. I usually finish cleaning the cup by dampening a paper towel with clean thinner and wiping it out. Don't leave plastic or rubber cup lids in thinner, it will damage them.

7. Sanding and Polishing Your New Paint
There are two types of pads wool vs. foam buffing pads. Wool pads generally do a good job in the hands of an experienced technician, but some of the newer foam pad designs offer advantages that shouldn't be ignored.
Some of the foam pads currently being manufactured are of a reticulating design, which minimizes or eliminates the splattering of the compound or buffing material, and ke