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Building Tips and technical articles. => Building techniques => Topic started by: Tim Wescott on August 25, 2012, 11:01:01 AM

Title: Heat-shrinking Silkspan
Post by: Tim Wescott on August 25, 2012, 11:01:01 AM
I dithered over putting this in "finishing" or here, but ultimately decided that it's more a structural question than a finishing one.

I was recently gifted a plane (thanks Randy) with a 12 year old silkspan and dope finish, and a honkin' big warp (this may be why you needed the trim tab) in one wing.

Based on some dimly remembered wisdom that I read a long time ago, I tried tweaking the wing and running over the silkspan with a hot air gun, just like you would with 'coat.  It works great -- the warp is so far gone, it's warped in the other direction (oops).

My question is: how is this going to work in the long run?  Does heat-shrinking silkspan (probably the dope, in reality) work?  Am I going to be doing this all the time?  Am I going to end up over-tightening the covering and splitting the silkspan?
Title: Re: Heat-shrinking Silkspan
Post by: Bootlegger on August 25, 2012, 12:30:16 PM

   y1   Keep us informed as inquiring minds need to know... #^   I think that it is a good thing to try, you never know just "what will be discovered" !!!
Title: Re: Heat-shrinking Silkspan
Post by: Jim Thomerson on August 25, 2012, 07:07:35 PM
Dope is a thermoplastic.  I heat things over an electric stove, and keep at least a finger in the heat.  If my finger is OK the dope will not be harmed.  One can heat a doped wing and get a small wrinkle out.  I don't like heating a wing to speed the dope drying because the warmed air inside will expand and balloon the covering unless the wing is well vented. 
Title: Re: Heat-shrinking Silkspan
Post by: FLOYD CARTER on August 27, 2012, 02:30:16 PM
You will never harm the paint or covering if you use a steaming-hot towel.

Floyd
Title: Re: Heat-shrinking Silkspan
Post by: Randy Powell on August 27, 2012, 03:31:17 PM
Tim,

Yea, the tab was for the warp. Kid built the wing and I tried to pull it out when we covered it but went too heavy on one side and pulled it the other way. A coat of thinner with just a touch of dope in it on the warped side may release it enough to let it pull back.