An M.G. Locost Build
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February 12, 2013
Month of Painting

After the coldest winter in almost 14 years (obscure reference to a 1970 Rod Stewart tune), frame painting has been officially scheduled for the upcoming 3-day weekend. In preparation for this, we've been doing some online research, which we know is always a little dangerous but is probably better than the alternative, although we don't actually know what the alternative is. What we learned from our online research is that we want to paint our frame with a 2K primer.

A 2K primer uses a catalyst or activator to cure the paint, rather than just letting it dry. There are basically two kinds of 2K primers, epoxy and urethane. Epoxy primers provide better protection but urethane seems to be easier to work with. Also, urethane primers and topcoats are very compatible, so you could theoretically prime the frame and paint it right afterwards, if you were any good at it, and possibly even if you weren't. We had some recent experience shooting 2K paint, and it turned out to be both easy and fun.

So I think we're going with urethane, although we're not quite sure how much to get. I think a quart would do it. Urethane is usually mixed 4:1, or sometimes 8:1, and possibly reduced by another 10-20%, so that could end up being a quart and a half by the time you're done mixing. On the other hand, it would really suck to run out. So I think if we can afford it, we'll go with two quarts of primer and two quarts of color. That actually sounds like a lot of paint. Hopefully it won't go bad right away.

The best thing we learned from our online research is that 2K primers, because they cure rather than dry, can be shot in temperatures as low as 55 degrees. 65 degrees is better, but not absolutely required. Temperatures for the upcoming weekend are predicted to be in the mid- to upper-60s, at least between noon and 3 p.m., so we're all set. And pretty excited about it.

  Rattle can paint on Locost A-Arms and links
click to enlarge

In the meantime we've been practicing with spray cans. We have all kinds of little parts to paint, and a couple of big ones like the roll bar and the rear axle. Each part needs to be painted a couple of times, starting with an etching primer, then a filler primer, and finally a color coat, which in our case seems to be either silver or black. And of course every part has to be sanded before each coat of paint. So there has been a lot of painting and paint-related activities going on. It looks like February is going to be the month of painting.

Locost parts in various states of paint  
click to enlarge

About half of the parts that need paint are things that we made, and the other half are parts that came off the donor in a somewhat crusty state. Most of the parts that we made are still pretty clean. A couple of the donor parts, being roughly 40 years old, have a little rust on them. The others have a ton of rust on them. So a lot of these parts are a project in themselves, and we could really use a sandblaster now, if we knew how to operate one. Or an acid dip, although that somehow seems even less safe than a sandblaster.

  Almost warm enough to paint outdoors
click to enlarge

Right now we have about two dozen Locost parts draped around the garage in various stages of painting, and another dozen or so waiting for their first coat of primer. As you might imagine, there's not a lot of room for them all in the garage, and a few parts, like the roll bar, have been relegated to the side of the house. It's all totally disorganized, and somewhat discouraging because we're not exactly getting expert results. We hope it all pays off down the road with some nice, colorful pictures for our website, but so far it's been no fun at all.

Freshly-painted steering rack trying to dry  
click to enlarge

Not only is the prep work for painting no fun, but the actual spraying is a chore, because spray cans have these tiny little holes for the paint, and so the paint has to have the approximate viscosity of orange juice, which is almost guaranteed to drip, run, sag, or otherwise look like the part was painted by a complete amateur. And as we've noted on many occasions, we may be amateurs, but we believe that we have progressed beyond the complete stage to the semi-competent stage, and have elevated our expectations accordingly.

  The first BRG partóspare tire carrier
click to enlarge

We really should've done more painting last summer. We knew someone was going to have to paint this stuff eventually, but most of it was stored away in various corners of the garage, out of sight and easy to ignore. But you really want to get things painted as early as possible. Installing a part a day or even a week after it was freshly painted is usually trouble. Paint may be completely dry in a week, but it's not seasoned yet. It's not tough enough. Paint has to be dry for at least a month before you can handle a part normally, and stick bolts through it, and clamp it to other parts.

So we're a little behind in our efforts, but hopefully we'll be all done painting in a week or so, although probably not. The chassis is going to need at least two weeks to dry before we can attach stuff to it, and even then we'll have to be careful. If we install the suspension in early March, for example, we won't be able to torque down the pickup bolts because that would leave ugly washer marks in the fresh frame paint. So we'll have to be careful. By April we should be okay.


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