Hi folks
I'm currently building 1/3 Taylorcraft from Bob Nelitz plans, which will be covered with Sig Koveral. I have used this material in the past a lot but only with the dope. This time I want to try something different. I have read, you can use Miniwax polycrylic to seal the weave and basicaly paint directly over that without the need of primer. I'm thinking of using acrylic paints. Also, the polycrylic can be applied as a top coat in a spray form. Taylorcraft has a lot of open structure.
Has anyone tried this process? Could you please shed some light.
Thanks

Haven't tried to use Minwax water-based polycrylic directly on fabric covering over open structure but here is something you may want to consider... Koverall shrinks with heat but only so far. Normally, I start with a base of 3 brushed coats of thinned nitrate dope to both seal and further tauten the covering over open structure, giving the structure more stiffness and strength. The polycrylic won't do that. It will not cause the covering to shrink further but will allow the covering to remain more flexible, not stiff and taut as a doped covering would be. I think you would be fine using the polycrylic over a suitably cured dope base (either nitrate or butyrate) of at least three coats. I'd let it cure a week or so after the last coat then you should be able to switch to the polycrylic.

BTW, the water-based polys like Min-wax are not hot glow fuel proof but can be made so by using Nelson's Hobby crosslinker. I suspect you're probably using a gas engine on the T-craft so that's not an issue. Built a 1/4-scale T-craft years ago with a 25cc gas engine (can't remember the brand) but sold it before first flight!

Hope this helps...

Curt

I don't think you want to try to paint anything over Butyrate Dope. I do not know of any type or brand of paint that will go over Butyrate and stay there. Usually, once Butyrate is used the only thing you can paint over it is more Bytyrate.

Yup. Dope goes over dope, but not much else will adhere.

If it were me, I'd dump the Koveral and use Natural Solartex. The Solartex doesn't require and adhesive, nor does it require sealing the weave. Most paints work well with Solartex, and no primer is needed underneath the color coats.

Someone is doing it over on the RCSB site. I prefer dope but that is not everyones available choice. I prefer Polyfiber on real airplanes.

I've used Polycrylic and Koverall on all my fabric covered models for years now. It works great!

Jim

Test piece first always a good idea. Ed

I use Minwax polycrylic to seal all my fabric covered planes. I can brush it on, two coats and wet sand with 400 grit. I then use Rust-oleum primer to fill any minor faults and wet sand till I am happy with finish. Then I just use Rust-oleum spray cans to finish painting color on. Never had problem with gas powered planes. I am trying on new plane using Rust-oleum " universal bonding primer " PN#285011 to see how this works as it is made to bond topcoat to difficult surfaces, It cost more and not sure if it can be wet sander to a supper smooth finish for final painting. Will try out this weekend to see how everything work out. Also if you are using glow engines you could use a clear overcoat on Rusy-oleum to be supper safe.
Best part is water clean up with poly.and no Bad fumes of fire problems to worry about.

Same here. It been my experience that it holds up pretty good to glow fuel too, up to 15% nitro anyway.