I inherited an airplane from a local modeler.  It's 20 years old, covered in silkspan & dope, and the covering is persistently slack.

I've been trying to steam out warps, and the covering keeps returning to slightly slack, instead of taut like I'm used to seeing.

Rumor has it that it was one of his first attempts, so I'm wondering if he went overboard on the plasticizer in the dope.

Is there anything that can be done, short of ripping it all off and redoing it?  Someone suggested a coat of revitalizer (dangit, I can't think of the right word), but AFAIK that's for dope that's lost plasticity, not for dope that has too much.

(the title suggests that a thin even coat of Viagra would turn the trick, but somehow I don't think that's going to help in this case).

Tautening dope usually does the trick.

I shall try that.  The thought entered my head, but I was scared...

How many coats?  Or should I just do one and see if it's working?

How long until I see results?

How long until I see results?

Could be as soon as the first coat dries.

I guess I should have clarified...the tissue tightened up wrinkle-free within an hour or two. The shrinkage continued through the night. I admit, I piled it on pretty good trying for immediate, nylons-on-a-fat-chick tight. I wish it had "burst a seam," instead of pulling up the trailing edge!

My question is really more -- if at first I don't succeed, how long should I give it before I try, try again?

A day or so, maybe.