Hello All,
  I use the old fashioned finishing system of nylon or silk with dope for the wings and tissue on the fuselage. The nylon for practice machines and silk on the bigger stunt planes. OK, I now use mylar under the silk, so not quite as old fashioned. I dye the silk before use and I even use printer ink in the clear dope, for the decoration. For fuel proofing, I spray on, what I believe is, a polyeurethane floor varnish! All this is to get the weight down. The result is a very lightweight finish that lacks little in strength.
  I don't aspire to the superlative finishes that weigh a lot, but any ideas to make a lightweight finish look a little better, would be appreciated.

Regards,

Andrew.
   

Hello There Ty,
  Thanks for the tip, in the rubbing down / polishing, what do you use as a polishing medium. I live in the UK so a generic name would be good. How much of the 6 coats would be removed in the process. Or put it another way, what would be the increase in weight?
  In the past I have been a very overwight builder, the plane, not me! I have now got a bit paranoid over weight and do everything to keep things light. My question re weight, is because I have never put on 6 coats of dope in 50 odd years of building, so I don't have that experience.

Thanks again,

Andrew.

Just read Windy's article in CLW and he stated that he thins the clear dope so that it takes some time to dry.  He also claims the longer the drying time the deeper into the wood the dope goes.  What got me was he said that before any dope the entire wood surfaces is sanded to a very smooth surface and vacuumed.  It was the five coats of dope that got me before any more sanding.  Then he says you don't have to worry about the fillets or silkspan lifting later on.  At least that is the way I read it.

Like Ty says, th emain part of making the finish *look good* is in the final rubbing/sanding/polishing part. 

If you are careful to get everything smooth and flat from the beginning, and do diligent sanding along the way, the *rubbed out* final clear is what pops.  Dope or automotive urethane seem to be the most used products used today for final clear.  Be real careful with the auto urethane, it gets heavy REAL FAST!

A *light weight* finish that looks good is pretty impossible unless you are thinking along those lines from the beginning.

Big Bear