Paintable fabric covering question
 

What type of paintable fabric covering (for control surfaces) are you using and where do you buy it? I'm not interested in Monocoat and similar plastic-type products. Starting a build of the Spitfire below after being out of airplanes for a few years.

Thanks

Probably the #1 choice is Solartex (for easy), followed by Koverall (which needs the weave filled with either dope or polycrylic). Both are heat-shrink. Warning: Koverall can crush and warp delicate structures.

Lest not leave out Poly-lite, a much tighter weave than Koverall hence easier to fill. If one was going to use self tautening dope then any polyester would do.

I appreciate the feedback, I'll check out each of these suggestions and let you know what I chose. Since it's only for control surfaces I don't want to buy a whole lot of products needed to apply the covering...

Dope over polyester sems easy and cheap, but it's been a really, really long time since I used any dope. It seems to me I just brushed on as many coats as I needed, is that right? However dope over polyester sounds heavy, since building a Spitfire any extra tail weight is a real problem...

Scratchie, if it were me, I would use Solartex and then paint it with the same paint you use on your plane. One small roll of covering is all that you would need to buy.

Iron it on and then paint - easy peasy!

You may want to check with your fellow flyers, someone may have some pieces laying around.

+1 even better!

Dope is pretty light. Two coats of Nitrate on the bare balsa, slap on the fabric and dope it down with more nitrate, brush 2 coats of nitrate on the fabric, top coat with either butryrate dope (if that's what you are using for the rest of the plane) or paint with just about anything over the nitrate.


carl

Another possibility for smaller models and for flight surfaces is polyspan. Here's a nice YouTube tutorial on applying it. I've tested it myself and it's very light.

On the other hand, I did a "puncture" test with polyspan vs. solartex vs. koverall and solartex was the clear winner. A pencil tip went right through the polyspan/dope covering (with a loud pop) and also through the koverall. It took considerably more force to break through the solartex.

how is the solartex weight?

It's light enough. For what I think you are looking to do, Solartex is your best avenue. I would however suggest using a supplement adhesive such as Balsarite or Sigs Stixit to insure the Solartex does not get loose.

Bear in mind that when you're covering with solartex, in addition to sticking the fabric to the frame you are sticking it to itself...at the overlapping edges. And solartex sticks to itself very well. Just make sure you have a good 1/4 inch of overlap.

BTW, I've found that as an alternative to possibly hard to get balsarite or stixit you can just use watered down white glue. Brush it on, let it dry, then when you apply the heat of the iron it reactivates ("melts") the white glue.

I use that method on wood, especially sheeting. Did not know it would work with covering, very cool. See fellas this old dog just learned a new trick.

Have a look at hammerd tips here http://www.rcgroups.com/forums/showt...2290028&page=6
It may help you

Living someplace fairly remote has its advantages. I'd also used this method to attach fabric to aluminum tubing.

Amazing stuff! But then Hammered is one of the most amazing modelers around.

Polyester fabrics with some type of paint (I like to use dope, personally) will be the lightest for a fabric type finish. Solartex is very strong because it has a coating of adhesive (more weight) on one side which binds the fibers together a little more. Be sure to use an adhesive on the structure before putting on the Solartex. It's great stuff but needs a little 'help' in that department (in my experience). Even though you intend using something like this on your control surfaces and some may argue the weight will be negligible one way or the other... just remember... the weight matters when you add everything together!

A square yard of Solartex might weigh somewhat more than a square yard of koverall or other polyester fabric. But you don't have to "fill the weave" when using Solartex. So the question is how does the weight of a square yard of Solartex compare with the weight of a square yard of fabric plus 2-3 coats of nitrate dope or polycrylic (plus the dope or balsarite you have to apply to the frame to stick it on).

Well said.

Solartex requires no primer, either. Color coats can be sprayed directly. This eliminates more weight.

Glue is heavier than paint. Dope is very lightweight since the vehicle in which it's pigments are dissolved/ suspended evaporates away. I can't remember the numbers but it is somewhere around 80%? I remember comparing Solartex to some doped fabric and I even weighed it. Unfortunately I don't remember the exact figures but my doped fabric was a 'smidge' lighter. Results may vary. The next time I crash and do a recover I'll definitely re-compare! Let's hope that doesn't happen any time too soon!

Man you can learn all kinds of stuff just cruising around reading threads. learning the many ways helps to make better choices whatever your doing.

Leroy

Poly-light system for me as well, but if I were going for the lightest, the old dope and silk is hard to pass. Dope the structure a couple of times, scuff with 1500 grit, lay down the silk, spray light mist of water over silk, pull tight with fingers, while wet dope perimeter, allow to dry and dope open bay areas. That is how I was taught long ago when I was messing with my ukies and free flights. Kinda miss the old days...

Bob

Sensei- tell ya what... I'm going to go the silk and dope route for the tail feathers of my 1/4 scale Franklin 'Eaglet' sailplane that I'm scratch building presently! I just might put silk on the top surface of the fuselage, too!

I am sure it will turn out beautiful, everything I have seen of yours turns out that way!

Bob

I use Stits exclusively and can tell ya it is lighter as a finished product than the silver Solartex, but don't remember the numbers. As was mentioned earlier the only thing left after evaporation is the color. Waconut is currently recovering a 1/3 scale Cub and is going to do a weight test for himself. So when he is done one could find some actual numbers in his thread if so desired.