dksoder

When you use dope and silkspan, on the first applications , do you use straight dope, or is it diluted to a 60-40 solution.

Jim Thomerson

If I want transparency, I use fairly thin dope for the first couple of coats and brush it through the silkspan, then go to thicker coats. If opaque, initial thicker coats are OK.

dksoder

To Jim Thomersom
I don't know if I am doing this right or not. I'm new to this, but thank you for the quick comeback. Mal

jessiej

Jim summed it up nicely. For more info you might do a search on the "Vintage & Antique RC" forum.

jess

Azcat59

I wonder where you are using it? Over open bays, as we used to do in control line (and I think they still do), it is pretty fragile and I don't think I would recommend it for RC. But I still use it frequently over wood areas on painted planes, such as WW II warbirds. Two thinned coats of nitrate on the wood, sanding slighlty between coats, then run the silkspan through a cake pan with water, and blot on newspaper so it is damp, but not dripping, lay it on the surface, dope around the edges, rubbing the dope in with your fingers. When dry, sand off the perimeter "flashing', and dope the center areas with thinned dope. Sand a little (don't fuss it all up though) between coats, and give it three or four coats, thinned some. After the last coat and sanding, you should be ready for primer.

Hope this helps rather than confuses.

Clair Sieverling

dksoder

Clair
Thanks for the comeback. Everyone is really helping me out. I am building a u-line stick model plane called the Buster. Now I am ready to do the wings with silkspan. I used it 40 years ago but just can't remember how I did it. If I recall , we mixed clear dope with thinner 40-60 and also I am not sure if I did the solid body or not. (It' he-- to get old) Thanks for all the help. Mal

Jim Thomerson

Be sure you get the wing outlines shiny with dope before you start covering. Stick the wet silkspan down with thinner or very thin dope. You may have to cut gores in the silkspan to cover the tips, or cover the tips with a separate piece. Be sure you run the grain spanwise. Keep the silkspan wet until you finish both top and bottom of a wing. I like to orient the wing vertically so both sides dry at the same rate. Helps stop warps. On the fuselage I would stick the silkspan down dry, just doping around the edges, then water shrink it. This will give you a very slick base to dope on and also the silkspan edges will stay where you put them. If you put it on wet, it can move around.

RaceCity

Silkspan is really "the stuff" for the right application. The techniques here for applying it are all workable. The basic idea is to get a base coat of dope down on the bare wood that the material can then be attached to. Since dope generally brushes a bit easier when thinned somewhat...that's a common means of doing it. You certainly want to thin the dope a bit when you are attaching the material to the prepped surface. This aids in penetrating the silkspan, and softening the underlying dope substrate.

Once the material is applied, a few thinned coats of nitrate dope help to seal the material. At this point...you can opt to just go ahead and put on your butyrate color coats....OR.....start applying sanding sealer. Sanding sealer can be made easily by blending talcum powder with Nitrate dope. This can be either brushed or sprayed. I prefer to tint (silver), thin and spray this mixture to get a more uniform coverage. This stuff dries fast, but it's deceiving! Dope gasses and settles over a period of time, so I would allow a coat of dope a minimum of a few days to settle down before sanding it. Real pro finishers will wait even longer. Wet sand this mess carefully. The silver tint makes it very easy to see where the low spots are, and also serves as a good visual indicator of where you are getting "thin". Try not to break through the silkspan when sanding!!!

Several application/wet sanding cycles will leave your model with an unbelievably smooth finish...ready for color coats.

LIGHTLY wet sand between color coats, and hit it with clear. Several coats with a wet sand in between each.

Polish the finished surface with compound (I like to start with white compound, and end with PPG DRX-10) and whoa.....

That's a gross oversimplification of the whole thing, and thinner "heat ranges" play a huge role but the finished results can be incredible.