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?

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. 

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.