I ha e built a fairly large wing that I want to cover in lightweight cotton. I cannot get dope, what can any one suggest could be used as a substitute for tightening and filling the weave?

Thanks

clear nitrocellulose lacquer. Basically the same as NITRATE dope... Nitrate doesn't shrink very much so the fabric will have to be taught before you apply it. You can make your own BUTYRATE dope (shrinks more) if you can get butyrate sheets, grind them up (a blender works well for this)into a coarse powder, and soak them in a GLASS or METAL container in lacquer thinner. They will dissolve. You need about 1 part butyrate to 2 or 3 parts thinner. It will take several days for it to dissolve. Keep it tightly closed.

If you can find some material that is heat shrinkable (such a dacron coat lining or a daccron aircaft covering such as Sig Koverall, Stits Lite, or Aircraft Spruce uncertified dacron) you can apply it with water-based polyurethane (clear). There are MANY articles here on that process.

Unfortunately, I am unable to get hold of any type of cellulose nitrate products at the moment.

I read somwhere that PVA thinned out might work!

regards

the PVA MIGHT be viable. Before I committed the airframe, I think I would build a test rig, a frame of balsa, and apply a piece of the fabric by glueing it around the edges. Keep it as taught as you can. Once the edges have completely dried, tried "painting" it with pva cut 1 part to 3 parts water. Brush it on LIGHTLY allowing it to dry between coats. See what happens. If it tightens the fabric put doesn't crush the test rig, it might be worth a try. Putting a bit of talc in the first couple coats might be worth a try, too, to help fill the weave.

Post back and let us know how this worked....

You can cover the plane using Sig Stix it or Balsarite. These are both glues that are painted on the areas of the plane that will contact the fabric. After the glue dries, the fabric is ironed on to the framework similar to monokote. The heat from the iron activates the glue which then allows the fabric to stick to the frame. After covering, the plane can be painted with a paint such as linear polyurethane or an exterior latex. Do a google search for Jerry Nelson paints for the linear polyurethane. The house paint is available at any hardware store.

I don't think cotton will shrink with heat so you will have to tighten it yourself while you are applying the fabric. A better substitute for the cotton is dacron or dress lining. These can be shrunk with heat.