Sealer for fabric
 

Questiou for all of you fabric users I have a bird (Weeks Special) that was covered with I think SIG fabric, it is now time to seal this material so it can be painted.

I have clear nitrate and buterate dope but hate the small so will a pollycrlic work?? will be using a laytex base for the color coats.

thanks for any help

Cheers Bob T

RE: Sealer for fabric
 

Hi Bob,
I have had great success with Polycrylic. I thin it about 15% wuth water and brush on 4-5 thin coats with a foam brush. You do not want to apply it too heavy or the PolyC will puddle under the fabric. I lightly sand between coats after the 2nd coat. Latex adheres just fine to the PolyC.
Good Luck!!
Anthony

RE: Sealer for fabric
 

I still use clear dope.

RE: Sealer for fabric
 

Anthony,
What do you use to stick the fabric to the wood?
Thanks,
Jim

RE: Sealer for fabric
 

Jim,

If I cover in silk, I use dope to seal the grain in the wood. This also protects the wood because I apply the silk dampened with water.

Old school, sure, but it works great and holds up. This model will be covered in silk and dope. I always look for reasons to show my work.

This model will also be CL.

RE: Sealer for fabric
 

Jim,
I hear you can use the PolyC to attach the fabric but I use dope. attach the fabric then shrink and then start applying the PolyC. Works well for me.
Anthony

RE: Sealer for fabric
 

Thanks Anthony,

Jim

RE: Sealer for fabric
 

What is exactly is pollycrlic or PolyC? Is this water, oil or lacquer/dope based?

RE: Sealer for fabric
 

It is Minwax Polycrylic. It is a water based urethane. You can glass with it or use it to fill the weave of fabric. It is a bit thick right out of the can and I thin it about 15% with water. It has little to no smell and cleans up with water. It does not get as hard as fiberglass resin but remains somewhat plyable. It dries fairly quick depending on temp and humidity. It will accept virtually any paint. I do prefer to apply a primer coat before painting but it is mostly to get a even base color before the color coats go down.
You can get it at your local home improvement store for approx. $15 a quart. I prfer using foam brushes to apply the liquid PolyC. You can also get it in spray cans for $10 a pop and use fro a clear coat. It is gas resistant but not nitro.
Hope this helps!!
Anthony

RE: Sealer for fabric
 

OK, when all else fails look it up... MinWax Polycrylic and others are basically
waterbased like crafters acrylic paints. What I didn't realize and am glad hear is that
a water/latex based coat can be used as the first coat on fabric. And now that I think
about it I remember spritzing water on my old tissue covered models to tighten them up.
So why couldn't you use some water based coating on fabric. I've just always used dope,
but when I had to patch a spot on an old plane few months back I couldn't believe I used
to do these things all the time in dope, but hey it was the '70s then. Dang, I had every
door and window open and was about to pass out. I love my monokote but there are
some things that just have to be done in fabric. Will have to dig into some threads
and catch up...
thx.

RE: Sealer for fabric
 

Thanks Anthony. cross posted. But just to make sure I got this right, you can use it directly on
the bare cloth right? to provide base coat? thx, again.

RE: Sealer for fabric
 

What can be used over the latex paint so the nitro wont eat it ?

Thanks, Glenn.

RE: Sealer for fabric
 

My recollection is that Behr clear, water based polyeurathane is fuel proof to 15%, at least, and will go over latex. As always, when using products that you are unfamiliar with, TRY A SAMPLE firs.

Les

RE: Sealer for fabric
 

Thanks for your reply, sounds good and I will do a test run.

GLENN.

RE: Sealer for fabric
 

I don't think the Behr clear is available anymore. I could be wrong.
For fuel proofing for nitro I used Nelson's Hobby Specialties clear but he is now out of business. I am strictly a gas guy now so I don't really have to worry about it.

Cliff,
You can apply the PolyC directly to the fabric. Thin the PolyC approx 15% with water and brush on light coats lightly sanding between coats after the 2nd coat.
Anthony

RE: Sealer for fabric
 

I don't think the Behr clear is available anymore. I could be wrong.
For fuel proofing for nitro I used Nelson's Hobby Specialties clear but he is now out of business. I am strictly a gas guy now so I don't really have to worry about it.

Cliff,
You can apply the PolyC directly to the fabric. Thin the PolyC approx 15% with water and brush on light coats lightly sanding between coats after the 2nd coat.
Anthony

RE: Sealer for fabric
 

"I don't think the Behr clear is available anymore. "

Seems like all the good stuff has a habit of disapearing:(((((((((

Les

RE: Sealer for fabric
 

I prepped the wood surface by sanding then spraying with water. After the water dried I sanded again. I put 0.75oz glass cloth down with polycrylic right out of the can using a foam brush wide enough to fit in the can. I let this dry for a couple of hours then put on another coat. The next day I sanded very gently to knock down bumps using 200 grit. You can see if you cut into the fabric. This starts to fill the weave very well. I think I put down six coats and got a nice and smooth surface that will require minimal primer. I have to wait until it warms up before I can do that! Polycrylic seems durable enough (it's a little soft) but epoxy would be better. For the price and what I want it for (sport scale) it's perfect!

RE: Sealer for fabric
 

Thanks for the info. How would this react to 10 to 15% nitro?

Thanks, Glenn.

RE: Sealer for fabric
 

PolyC is not glow fuel proof. Even 0% nitro methanol-based fuel will cause it to soften. Nelson's Clear worked great as a fuel-proofer over PolyC when used with the cross-linker but sadly, Jerry has had to close up shop. I went to System Three's website (what Nelson's was based on) and low and behold you can get the Clear gloss and satin from them. It even comes in small quantities (4 oz.) for a fairly reasonable price. Use the cross-linker that goes with it for a fuel proof (at least 15%) finish.

BTW, I use the cross-linker even when I don't need the fuel-proofiness like on electrics because the finish is harder and more durable after curing.

Curt

RE: Sealer for fabric
 

I looked on system threes site and they have a lot of stuff how can i find what you used ?

thanks Glenn.

RE: Sealer for fabric
 

It's call "WR-LPU Topcoat". Here's the link:

http://www.systemthree.com/store/pc/...opcoat-c29.htm

BTW, you'll need to order the cross-linker seperately if you buy the 4 oz bottles. You'll find it on the last page. Since only 6 - 8 drops are used per ounce of paint a 1 oz. bottle will go a long way.