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Building Tips and technical articles. => Building techniques => Topic started by: Randy Powell on January 16, 2008, 10:40:44 PM
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OK, on this latest classic plane (my refinished Cobra), I decided to forgo my usually use of catalyzed polyurethane and shoot clear dope for the top coat. It is, after all, a classic plane. I haven't shot clear dope as a topcoat in a long time. How many coats do most guys do? I've got 4 medium coats on it now of pretty heavily thinned clear and it's pretty shinny and looks actually pretty good. But when I go to rub it out, I don't want to go through the clear. Were this catalyzed polyurethane, I'd say I'm done, but I've been thinking that another coat of two may not be a bad idea. Weight is OK. In fact, looks like I'll lose close to 5 ounces off the original finish.
So, opinions?
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Ty,
Yea, I've got about pint of actual paint on now. That translated to about a quart and a half of paint shot. One of the problems with using Randolph's or Certified in gallon cans from the aircraft supply places is, the stuff is like maple syrup coming out of the can. You have to cut is something like 1 part paint to 5 parts thinner to get it to go though a gun. Even more when it cold. The stuff I've shot on the Cobra is probabaly thinner 7 to 1. Gets kinda hard to figure out how much actual paint is on the plane. Wish I would have just started with a container and said, this much paint will go on the plane, then I could have ignored the amount of thinner it took to get it to spray gun consistency. But at a guess, I'd say that 3/4 of the original pint is on the plane.
I suppose I'll hit it with at least one more coat.
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Randy,
I'm still using clear dope and I apply 7 coats.
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Crist,
OK, you talked me into it. I have the shop heating up now. I'll get at least one more on it. Should have some pictures by the weekend. If you squint a little, it looks pretty good.
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Hey Randy, it looks great from here
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Mark,
I don't doubt it. That's about where you'll have to stand for it to look good.
Really, it's not horrible. But I learned a lesson about shooting color when it's cold and humid. You just have to let those trim color completely dry out. If it takes 3 days, it takes 3 days. I was pretty frustrated when I would pull tape and get a really clean, sharp line then have the flash fold over and stick leaving the edge ragged. If I had it to do over again, I would have shot the trim and just left the tape on for a couple of days until I was absolutely certain that the paint was dead dry. Sigh... Ya think you know something ...
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Yea, I've got about pint of actual paint on now. That translated to about a quart and a half of paint shot. One of the problems with using Randolph's or Certified in gallon cans from the aircraft supply places is, the stuff is like maple syrup coming out of the can. You have to cut is something like 1 part paint to 5 parts thinner to get it to go though a gun. Even more when it cold. The stuff I've shot on the Cobra is probabaly thinner 7 to 1. Gets kinda hard to figure out how much actual paint is on the plane. Wish I would have just started with a container and said, this much paint will go on the plane, then I could have ignored the amount of thinner it took to get it to spray gun consistency. But at a guess, I'd say that 3/4 of the original pint is on the plane.
I suppose I'll hit it with at least one more coat.
HI Randy
With the Randolphs or Certified you can use a coat or 2 less dope.It has a lot of solids in it
I use 5 to 6 on SIG , 7 on Brodak ,and about 4 on Randolphs , Certified is very thick too.
. Best way not to rub though is to flatten the plane on the 4th coat with 00000 steel wool or 2000 paper then put a last wet coat on the model.
I also spray all of the ink lines and letra sets or decal with a couple of very fast light coats before starting, then on the first coats I use a fast thinner and switch to a slow drying thinner on the last coat, this lets the dope roll out flat.
On My DREADNOUGHT I use PPG thinner with the dope 85 degree stuff first, then on the last coat I used the Hi Performance clear with the 105 degree thinner, I could have used this with teh dope also.
Randy
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Randy,
What you describe is pretty much what I've seen. The last two coats, I shot the paint then filled the gun up with straight thinner (maybe 2% clear dope in it) and shot that one. Gave a very nice gloss. This is shooting in very cool and humid conditions. And I agree. There are 5 coats of clear on and my sense it, that's plenty.