Painting your Locost
This article isn't so much about painting your Locost as it is about painting your Locost parts. Painting the bodywork is a whole separate issue, fraught with its own choices and problems that we don't really want to get into now. All we want to talk about here are the pieces that go into your Locost, pieces that may or may not need paint. This includes parts from your donor, as well as your frame and suspension bits.
You are of course perfectly free to install old and crusty parts from your donor without any refurbishment. We won't stop you. But you might consider at least cleaning them up first. On our Locost we cleaned and painted close to a hundred donor parts altogether, and we didn't do a particularly great job of it, or even a good one, but it was still a lot more fun to install things that at least simulated new parts.
The only real issue for us was waiting for paint to dry. We just never had the skill or talent for that. It's not a good idea to install recently painted parts. We think you should wait at least a week, to give the paint a chance to not just dry, but harden. What we should have done, and what we recommend to you, is to paint things a good month or two before the car will be ready for them. Even longer is okay. Paint them and put them on a shelf. If you have to dust them off before you install them, that's a good thing.
Many of the parts you paint will have already been painted once or twice before. A few of these can just be wet sanded smooth and repainted. Most parts will need the old paint completely removed, along with a healthy layer of rust. Our favorite method of rust removal is a wire wheel. There are many chemical agents for removing rust, but none of these are anywhere near as satisfying as brute force with sharp, steely wires. As long as you wear gloves.
Sometimes you can't get every last bit of rust off, and that's okay. You tried. They make paint for people who tried but couldn't get every last bit of rust off. It's called primer for rusty metal, or something similar. There are also the so-called rust encapsulators, like POR-15, which seal off all of the rust from the outside world, however we think those kind of paints are for people who didn't really try.
If you manage to get rid of all the rust on a part, or all but a smidgen, you can paint it with regular primer, of which there are only about a million types to choose from. The best are the 2-part epoxies and urethanes. These end up really tough and make a great base for the top coat. Unfortunately they need to be mixed and sprayed with some kind of compressed air device. Products have recently appeared on the market that spray 2-part paint from a can. We haven't tried these and won't comment, but we're as skeptical as you are. So maybe just that one comment.
You can also buy one-part clean metal primers and self-etching primers in a spray can. We've tried both, and the clean metal primers work well. We've had no luck at all with self-etching primers, which certainly could be our own issue but we won't use them ever again. We're not sure what the paint thinks it's supposed to be etching, but we couldn't get it to stick to anything with any regularity. Probably conditions have to be just right. We have no idea what those conditions are.
If you want to etch your bare metal before you paint, we recommend you buy a quart or two of real etching compound. We actually like the POR-15 products for this. They'll turn your bright shiny metal a dull gray with streaks of brown, which will not only seal out rust but will latch onto the first coat of primer like Velcro. Pour what you need into a paint cup, wet the part with water, e.g. from a hose, then paint on the etching compound. Leave it on at least 5-10 minutes, but keep brushing on more so it doesn't dry. After the part is thoroughly etched, rinse it off. Apply primer as soon as it's dry, or shortly thereafter.
Steel parts don't absolutely need to be etched, but aluminum parts do. The paint will just not stick otherwise. Of course aluminum parts don't need to be painted as much as steel parts do, because they don't look as bad when they rust. But they do rust, and in any case all parts look better painted. Our favorite aluminum etching compound is a product called Alodine. It turns your aluminum gray with streaks of yellow, and it's applied the same way as steel etching compounds.
Note that etching compounds are not particularly toxic, but considering what they do to metal, it's probably a good idea to use them in a fairly isolated location, or at least one that doesn't drain into the ocean. And wear gloves. We etched most of our parts over the lawn, likely violating hundreds of local environmental ordinances, but at least the lawn didn't die.
Once your parts have been etched and primered to your satisfaction, sand the primer lightly with whatever grade sandpaper you happen to have lying around that isn't any coarser than 180 grit or finer than 400. You shouldn't leave any dust on the part, so wipe it down with the proverbial soft, clean cloth when you're done. You could also use a tack rag, and we have, but if you're not careful you can make a mess with it.
If the part you're about to paint has surfaces that would best be left unpainted, you will need to mask off those surfaces. We like to use masking tape for this, although in a pinch we've used electrical tape, cellophane tape, and even dirty rags without horrible results. Before masking be sure the part is clean. Masking tape won't stick to a greasy surface. Paint actually will, although not for long.
Once the part is ready for paint, figure out how you're going to apply it. You can brush it on, spray it on with a rattle can, or go full-on pro with a compressor and spray gun. Each has advantages and disadvantages. We like to brush on paint wherever we can. Coverage is excellent and the mess is minimal. The only downsides are surface finish and time. Some brushed-on paints can leave a nice, smooth surface if conditions are right, but again we don't know what those conditions are.
Next easiest is the rattle can, and don't underestimate the sort of results an experienced painter can get with good rattle-can paint. There is a bit of a problem with overspray, unless you're out in the woods and upwind of the part you're spraying. Coverage with a rattle-can is usually weak, and attempting to improve it with a thicker coat never works. Multiple (like 5) thin coats are best, with 10-30 minutes between coats, but who has that kind of patience?
Not all rattle-can paints are the same. We like brush-on Rustoleum, but the same paint stuffed into rattle cans is vile. Whatever solvent they use to get the paint to come out of those tiny nozzle holes prevents it from ever drying, unless you get it on paper thin, or thinner. Krylon is much better when it comes to application and drying, but it's kind of a girl paint and we have our doubts that it lasts as well as guy paints like Rustoleum. This could just be our personal bias.
If you want both a super finish and excellent coverage, you have to use a spray gun. A spray gun is easily the fastest way to apply paint. A gun puts out about 10 times as much paint as a rattle can, in a much wider pattern. The paint inside the gun is a little thinner than brush-on paint, but not nearly as thin as rattle-can paint, so coats are thicker. You can use a two-part paint in a gun, giving you a much harder surface when it's dry.
A spray gun also makes the biggest mess. The thicker paint stays wet in the air longer, ending up on every surface within 10 meters of your paint area. Every surface, horizontal, vertical, or inverted. Fortunately, plastic tarps aren't all that expensive. If you haven't done it before, using a spray gun can seem a bit intimidating at first, but it's not that much different from using a rattle can. It just takes a little practice. Watch YouTube videos.
We should mention powdercoating as an alternative to paint. Great stuff. Expensive. There's very little effort involved if you don't count driving to the powder-coating shop, and the mess is minimal, at least for you. Colors can be limited, and I haven't seen any really glossy powder-coated surfaces, but it's glossy enough for car parts. Coverage is excellent, and the finish is at least as tough as epoxy paint. Not chip-proof, but close.
For aluminum, there's also anodizing. This uses a process similar to plating steel, but that's as much as we know. Like powdercoating, anodizing is probably something you have someone else do, although we've heard reports that it can be done at home, with the proper equipment. The mess could be considerable. Anodized parts look excellent and stay that way for a long time, but as far as we know there are only a few colors available.
In the end, most of your Locost parts will likely be painted with a rattle can. It works better for smaller jobs, and it doesn't require any tools. Most people paint the frame with a brush, as we did, but you can fit everything else into a small spray closet, or carry it out back to the woods. Have patience, take your time, and do it right. But do it soon. Don't wait 'til the last moment.
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