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Building Tips and technical articles. => Paint and finishing => Topic started by: Avaiojet on March 10, 2014, 07:40:27 PM
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Miniwax Polycrylic water base clear satin finish.
Has anyone ever use this product over open bays that are doped or just over dope itself?
Charles
Edited for spelling
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Charles,
I used this on a Magnum for the fuse, I put two coats over paper, it was very heavy. I think either Steve or Doug Moon did a lot of work using it as base coat for solid, could do a search on this forum for that.
Not sure how it would work on open bay but thinking about it if you have silkspan covering maybe since it is water base it could go on as the first coat and would shrink the paper. This might give a good base for the rest of the finish. Might work with silk. You could do a test square on a 1'x1' box rack and see if it shrinks and how much weight it adds.
Best, DennisT
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Dennis,
I have already been experimentating with other options besides dope.
I really don't want to use dope. "Odor." My background is automotive products. Used them on models since the early 80's.
The Nameless model I had at the field had Polycrylic on the fuselage. In fact, everything but the wing, stab and elevator were silked using polycrylic. Works well.
No clue about open bays yet. I may continue to use dope there.
Thanks for the reply.
Charles
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Remember that Minwax polycrylic is _not_ fuel proof. It requires a fuel proof coating on top of it (unless electric) If you are going electric I am unsure how well it handles fuel residue from handling, such as a pit situation.
One nice feature of being decidedly not fuel proof is you can use denatured alcohol to strip the high points of the finish, instead of sanding.
I found polycrylic heavy in my experimentation. I have not tried thinning or shrinking coverings with it yet.
Phil
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Phil,
I've played around with different products because I'm going 98% electric. I'll keep a gas for the gas. n~
I wouldn't put a water base chemical like Polycrylic over bare wood. You can put it over dope but not dope over it. I scratch everything I can between coats. I also do the masking tape test.
So, I used a lacquer based wood sealer on the bare wood, just a couple of coats, then I used the polycrylic. No dope over any of this stuff.
Look, I'm taking a different approach. No color dope for me.
I'm going to see what I can get away with using rattle cans over Robert's 540. NAPA's 540 introduced by Robert. As he says, it's great stuff, and it is.
Rattle cans. Sounds funny for a guy that made his living with an airbrush for plenty of years, but I'm looking for simplicity. I'm old, washed up and my time is taken up with tennis.
Roberts 540 over the Polycrylic. I'll sand most of it away. Board it as flat as I can without hitting wood.
When I'm done, "At the end of the day," as they say, I'll finish with a two part auto clear. Said this many times.
FYI, I don't find the Polycrylic heavy.
Just enough clear for a cover and a shine. Done!
I just have to build a model light enough to paint. LL~
Charles
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Charles,
I'm not sure what you're asking, but I too use lacquer sanding sealer (Deft or Minwax) for the first two coats, even over the open bays. I then use the same sealer mixed with a little talcum powder for the next two or three coats over the wood parts only, not the open bays. Then shoot a couple of coats of high fill primer on the wood parts only, not the open bays. Final coat is light coating of primer sealer including the open bays for color stabilization. Lightly scuff with 0000 steel wool, vacuum, tack rag, then color. I use Dupli-color lacquer for all primer and color. Three part PPG clear over entire plane and done. I handle the plane using gloves and use a 3M filter mask. The mask will actually block the lacquer odor. Amazing! Cannot believe the odor in the paint room when I take the mask off!
I've got a Continental in primer right now. If you want pictures, let me know.
Paul
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Paul,
We're almost the same.
Are you using aerosol cans for Dupi-color?
Yes, I would like to see your work! #^
Charles
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Here you go Charles. This is the Continental ready for the primer sealer (my last step before color). I use a bright shop light over my shoulder to show shadows in the surface after the final sanded coat of filler primer. I then fill the flaws that show up with shadowing using spot putty (that's what you see in the photos). The primer you see on the open bays at this stage is a very light coat to allow me to see pin holes the lacquer may not have filled. Do not sand this coat! You'll ruin the covering.
As for spray cans, I use both spray gun and spray cans for the color, depending on the amount of coverage required. Everything is lacquer except the clear coat. Easy to apply and easy to repair.
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Paul,
Thanks for the photos and the text.
Really nice work.
You have your control surfaces detached at the moment. When do they go on?
Do you do the masking tape test?
Believe it or not, I spent some time sanding my open bays on the nameless with 360.
I gotta scratch things up.
I'll do Robert's 540 and that's it for primer.
I'll take much of that off then "shake n bake," rattle can time!
I have a compressor and all the stuff, I just want to keep it simple.
Rattle can Rusty Dusty, does his stuff with cans. He actually convinced me to try it.
Thanks again for those photos.
Don't be shy, post whatever ya got!
Charles