Auto-Phile #87 By Tom Wilson

So you want to paint your car? That means you are an optimist! Painting an automobile takes a great deal of money, time, patience, sandpaper, paint, but most of all, patience. Most of us do not have all of these, particularly the patience.

Sticker Shock: You took your car out to two or three nearby body and paint shops and were given some “rough guess” estimates on how much money it would take to make your sow’s ear into a silk purse. You thought if you just went to one more shop, you would find one with a price for the job that would bring the process into your own financial ballpark. But usually the next price was either (1) even higher, or (2) when you looked at a couple of examples of their work, you thought: “Good grief, I can do as good a job as that!” You may be right, but you are probably wrong. Optimism can be good, but it may falter on the road ahead if you go ahead with the project.

Nevertheless, I would not want to discourage any of our stalwart readers, especially those souls with more time and less money to waste.

Experience: I have painted about four or five cars in my lifetime, and I sure would not brag about any of them. As I write this column, I am deep into a full paint job on a disassembled car that needed a total (and I mean total!) restoration. I have had to take the pains to improve my work, time, tool, and patience standards in order to execute a presentable and credible job. The process has been a real lesson for me in developing my own skills, supply stocks, tools and various equipment, budget allotments, and most of all patience, which is probably my worst character trait…not much patience and attention to detail.

Equipment? Tools, and knowledge of their availability and usage may come from a variety of sources, some very unexpected. Here is my best and most embarrassing example: It came at one Christmas gathering about five or six years ago. Each year we gather with my wife’s sister and her husband, Norma and Bud Wenning, of China Township, over in St. Clair County. Many presents zip back and forth between the sisters, grandmas, cousins, aunts, etc. Bud and I have taken up the practice of leaving the women to take care of the bushels and bushels of family and kid stuff, and we each year find one present for each other that is somehow related to autos or work. One year I opened my present from “Uncle Bud” and found this funny-looking scoop thing with a long handle. I had no idea what it was, even when I looked at the notes on the packaging! “What?” said Uncle Bud. “You’ve never seen a viscosity cup?” I felt like a dunce, naturally, but Bud explained that the cup is to be used for properly mixing paint for spraying, which he does in restoring the private aircraft that he owns, buys, sells, and flies. The paint is measured and mixed with its proper thinner/reducer, and then the viscosity cup is dipped into the stirred mixture and drawn out to run a thin line of paint back into the mixing container. Time is measured from the second the cup is lifted out and the paint starts running out of a tiny orifice in the bottom of the cup to the exact moment the stream stops, which happens with a very sharp cutoff. Timings are quite different: 25 seconds is a thick mix, and will go on the sprayed surface in larger paint droplets, possibly leaving some bumpy texture. A thinner mixture will drop through the orifice in less time, say 17 or 18 seconds, depending how you blend the paint and reducer. Each type of paint has different specifications for mixing. A card comes with the viscosity (sometimes called “Zahn”) cup and on it is a long list of popular paints and various other specialized fluid finishing products. Most paints you purchase are produced by companies that provide specification sheets for proper mixing proportions. Usually there are no specs on the paint containers, so the viscosity cup is handy to have around. I am still astonished that I had done (lousy) paint jobs on several cars, but never even heard of the viscosity cup! I still have the same cup, and use it regularly. Perhaps I also keep it as a reminder that I never will know it all about automotive painting, but I better keep trying…at least I will progress a little bit, hopefully!

Improving skills: To try to improve my hopeless skills, I signed up for a beginning painting class at the local community college. As I continue with my current car project, I keep the lab work sheet that I used in the class right there by my work bench, alongside the mixing stuff, spray guns, gun cleaning tools, fillers and perhaps that ice cold beer I just brought out from the kitchen! The lab sheet, created by my instructor at Washtenaw Community College, lists exact sequences and materials for several types of painting processes, from bare-metal preparation, to priming, to basecoat color painting to clear coat, to fixing scratches, runs and particularly keeping the job clean with supplies that I never had in my work space. This really takes a bundle of patience, which as I said, I do not have in abundance. I just have to buckle down and do every step right, and guess what? There will still be flaws in every step that I have to go back and fix. Texture from bad mixing or spraying techniques, cracks that I missed when repairing the fender, little wavy dents and bumps, repairs that the sandpaper actually breaks through to on thin metal, and on and on…. And on and on I go. Is there any end in sight? Probably not, but each worker and each job has to be judged by its own demand for a certain degree of perfection. This is where the patience comes in, making the decisions and judgments, evaluation of the problems and what step to go back to, to solve these problems. It does not come easy, but experience and practice may build your skills and make the problems smaller, fewer, and easier to overcome.

Paint mixing is a necessity in auto refinishing. You can have the paint mixed to the proper color and type at the store where you purchased it, but you will still have to mix it with the reducer, and with modern catalyzed paint, you will have to mix in a hardener and paint within a certain time framework, or the paint will start setting up and be worthless. The mix sheets from the paint supply companies provide the necessary specifications for the use of their products. And it would be important, when you buy the paint to be sure to ask for a copy of the mix sheet. Also, make a couple of copies of the sheet, and write what job you are using that product on. Keep one on the wall near where you work, and the others in a safe place, perhaps a file folder for the car you are painting, in case of loss.

This is the kind of clerical work that I have the most trouble with. Keeping copies of everything, making notes, keeping a work log, all of these, while time-consuming, at least make the work less confusing. Any time you start in again on the job, you can look at your notes and figure out just where you were. Eventually, I hope that some of these skills and methods will become second nature, but I won’t hold my breath on that one!

Safety is always an important concern. A typical commercial body shop has sufficient revenue flow to purchase and install excellent ventilation, hazardous-waste disposal systems, fire security, proper lighting, and so forth. Most home-type shops will not have such sophisticated equipment , and surprisingly, a few of the commercial shops do not either, but these mammy and pappy shops are getting harder to find, as OSHA (Occupational Health and Safety Administration) rules and state safety and EPA officials increase surveillance of safety and environmental systems in shops throughout Michigan. Your home shop will not be covered and surveyed by the officials, so unless you carry out some pretty blatant disposal and hazardous practices, you will be on your own. Your own health and risks to your own property will be your own call, so you will definitely need to consider how to protect the air you breathe while working, your flammable materials from combustion, and every aspect of safety to your life, health, home, property, family and garage, as well as your project car.

Sandpaper: Yep, there are a million grades, textures, colors, shapes, and qualities of sandpaper. What to buy? Can I skip that kind and still get a good job? Machine or muscle? Do I have to have a compressor? How many power tools do I need? Should I use electric or pneumatic? How fine do I have to go to not have sandpaper scratches show through the paint? I can’t answer all of these questions in this short column. But, for example, I am currently sanding in 400-grit wet and dry paper, using it dry. When I pass my hand over it, it seems beautifully smooth. But then I think back to painting-class lab, and remember seeing scratches from 400 grit paper that had to be sanded out when I was working in 1000-grit paper later! These are things you will have to learn largely from a trial and error process. There are lots of ways to go wrong, but each mistake can provide some valuable lesson – (well, unless you burn the garage down!) Here are a few things I learned in the sandpaper department alone – they may be helpful, but certainly not a complete guide to successful painting.

Buy open-coat paper for most sanding processes. This paper may be blown clean with an air gun for longer life, until the grit in middle of the paper feels smoother than at the corners, then throw it away! Wet and dry paper (the black stuff) can be used either way, naturally, but if you have no water supply, i.e. sink, fresh water plumbed in to your work space, for frequent rinsing of the sanding scum off of your panel, it would be best to stick with dry sanding. You can blow the grit off with an air nozzle, and vacuum up the mess later – especially before painting! A Non-open-coat paper will plug up with paint dust quickly, and be impossible to clean for continuing abrasion of the work surface. Keep a good supply of sanding blocks handy, some hard, some flexible and some soft, for surfaces that are flat, curved and in some cases, irregular. Have a variety of sizes of block, for large areas and for tight corners. Power sanders may be air-driven or electric motor jobs. The pneumatic ones come in a variety of types. A pure pneumatic rotating disc sander with a coarse grit, such as 60 or 80 can be used to quickly strip off rust and old paint in most areas, but is no good for paint finishing. A DA, or DOUBLE ACTION sander is a pneumatic sander that can rotate a sanding disc or orbit it for a finish with less whorls in the resulting surface. You would need one of these. These pneumatic air tools use a lot of compressed air, and you can’t get by with that little hand-carried job you used to spray the house or your models when you were a kid. You should have a rig with at least about a ten gallon tank. Some use 240-volt electric supplies, but some modern compressors do just as well as these on only 120 volts, so don’t plan on wiring your garage for 240 volts yet! (Like I did!)

One problem with air compressor-driven tools is that the pump is frequently kicking on and driving you nuts with all the noise. One possibility is to install the compressor outside, in its own little doghouse. Good idea, but on rainy days it may take in more moisture than it would inside, so you need to be extremely astute about bleeding the air from your tank and water traps every work day. Then there is the problem of potential theft….. I still have my compressor inside, but am currently in a phase of painting preparation in which I can use (1) a lot of hand-sanding processes, and (2) a nice little 5” diameter electric-powered orbital sander. It even has a cute little dust back which picks up some, but not all, of the dust that is drawn in through a circle of holes in the disc-holding Velcro-type pad by an air turbine inside. They did not have any of these in the college painting shop – I bought it on a whim, and it has turned out to be a real winner, particularly for flatter areas where I don’t have to worry about the power-sander burning through the primer on curved or high-creased areas,

Space: Most home work spaces/garages have only a 10 x 20 or a 20 x 20 foot garage. This can be a real problem. If you are painting an assembled car, rather than a part at a time, you will have a lot of trouble with (1) getting enough space to get back and shoot the spray at the car, and (2) ventilating enough to not kill yourself! You could probably disassemble some parts, such as a small component, or a fender or door, etc., and provide enough ventilation to get most of the paint overspray out with a window and the door open. In this case, it might be wise to spray small stuff inside and, either paint the larger portion of the car at a friend’s (larger and better ventilated) garage or failing all else, outdoors. Painting outdoors is no longer legal for commercial shops, but for the home-grown avocational painting process, such activities are a “gray area.” Checking with local environmental authorities may be informative. Should you run into a brick wall in this matter, you could still do all of your preparation work at home. Mask off other parts already prepared for final painting as you do each one. This prevents overspray from getting on another part while you are working. Even small shots of sprayed primer…even from a spray can…will overspray on other objects, and they will have to be cleaned. And overspray dries hard fast!

Then either hire a nearby body shop do the final shoot, or perhaps find a shop that would permit you to spray the car yourself in their facility for a rental fee. The advantage of that is that you might get some pointers on your job and methods. It pays to know somebody who knows somebody who….etc.

Painting perfectly is no picnic. Your first effort will be challenging and probably far from flawless. Automotive painting is for the tenacious soul who is willing to put in the time, money, and concentration to stick with it. Most of us don’t qualify at all.
Some, given sufficient time, determination, advice, and help can do a tolerable job of painting an automobile, and when they are done can look at that car and say “I did it myself!”

Copyright: 2005