Ok I recently purchased some Sig Nitrate Dope and need to get the thinner as well. Unfortunatly the hobby stores around me do not carry any of the dopes or thinners. I wanted to order some but was wondering what was the best thinner to go with. Should I just suck it up and order from SIG or will any brand of dope thinner work? Thanks! Jon
The method I have instructions on on calls for applying dope to the balsa letting it dry. Then put your silkspan on using a spray bottle of water to get it to "stick". Then brush a 50/50 mixture of dope and dope thinner onto it causing the dope already on the hull to reactivate and essentially glueing it to the hull. I have never done silkspan before so I was going off what I had. How does the acetone work?
I ve not used thinner on any of my ships, I don't think its necessary. Haven't seen anybody explain why its needed yet whenever these threads pop up.
Ok so how do you do it? Just a layer of dope then silkspan then dope again? I am open to anything because I have never done this before.
That is a great method for attaching silkspan to model aircraft. The easiest method for our ships is to lay the silkspan on the balsa and use dope straight from the can. Some people may use a light dusting of spray adhesive to keep the silkspan in place before doping it. Do not try to spread the dope out like paint. Keep it fairly thick and wet on the silkspan and make sure the dope soaks all the way through to the balsa below.
Hmmm ok I will try it that way. Seems easier then doing it the other way haha Why do you not want to spread it out like paint?
If dope (or clear lacquer which works as well and is much lower cost) is spread out too much, it will not soak through the silkspan and stick to the balsa under it. Don't be stingy with the dope.
Like using resin over fiberglass. Make sure there is enough dope to soak through the silkspan into the wood.
So far I have been using 50/50 solution of wood glue (Tight Bond III) and and H2O. No fumes to worry about. Seems to work just as well as dope.
whats the best way to paint a hull? What I mean by that is it best to just paint the whole thing grey then paint the read area or is it better to just paint the top and bottom halves their respective colors only? Thanks!
oh and I figured out why one needs the dope thinner. It is to get the dope off your hands after use.....
Ahh, never had that problem. Still don't understand why some people might want to thin out the stuff going onto their boats though.
I use a quick coat of 50/50 dope on the inside of my ships to seal the balsa. For the outside, I paint the balsa liberally with neat dope, then use the 50/50 mix to apply the silkspan. I get a nice smooth finish this way.
My method for Balsa prep: lay balsa on sheet of aluminum foil. coat one side with a thin coat of liquid ( not gel ) contact cement thinned 30 % or so with mek. Do it all outside. Lay silkspan on while it is still wet, smooth it out with a flat piece of flexible plastic so the cement gets into the silkspan, then cover with another piece of aluminum foil. Sandwich between two flat pieces of wood and put weight on it overnight. The cement should saturate through the silkspan and eliminate the need to recoat it before applying to the hull. It will remain tacky underneath the aluminum for at least a week. When ready to apply to the hull, paint several ribs with contact cement, wait a few minutes and then position the silkspaned side of the balsa and trim to fit. Once in position just press it hard against the rib and it will stick tight, no problems with the silkspan layer and the balsa separating later. After covering the whole ship, go back and sand the edges smooth. Apply another layer of silkspan to the outside by painting it on with clear dope. Then paint with Interior Flat Latex paint in your choice of colors. Patching holes I just paint a silkspan patch over the hole with clear dope. If I want it to look nice I go back and touch up the latex. Larger holes from multiple hits in a small area ( thumb size) sometimes need reinforcing with sigment or ambroid to reduce later tears in the silkspan. The theory is water wetted balsa takes nicer holes than dry balsa, no water inside the hull to soak the balsa so it doesn't matter too much what is used there. Interior flat latex and dope let enough water through that the balsa gets a little soggy. This seems to work in practice since the under the waterline hits are cleaner holes than the above hits. Using the BC 3" wide balsa I never have any failed drops. penetrates at about 10". The 4" stuff is stiffer and thicker and should be sanded prior to applying the first silkspan. A good 36" sheet of balsa held level at one end will droop to 60 degrees or more at the free end. Ron Hunt
Well I have one side completely silkspaned. the issue with silkspanning before the balsa is on the hull, as it was explained to me, is that with the 1/8" balsa armor, it can be very difficult to get it to bend to the hull form once doped and silkspan has been applied.
