Its far easier to do with two people. Also its neccesssary to let the covering cool a bit before the induced twist is relaxed.

Normally I will have one wing half flat on a table and weighted with sand bags the other panel extended off the edge of the table. The helper will induce the reverse twist at the extended tip from a comfortable sitting position by hand until the the covering shows diagonal and paralell wrinkles near the wing tips.

You then use the iron or heat gun to remove the wrinkles untill smooth just as if you were covering. I find the heat gun more easy to control than an iron. The helper must continue to hold the twist untill the the surface cools a bit after the wrinkles are removed before relaxing.

Now invert the wing and repeat the process on the bottom surface. It may be neccessary to do this several times to get it right. Another important point is normally it is better to have a little wash out on both wings (trailing edge up a bit when flat on a table near the wing tips) than the other way around so in most cases its better to induce wash out rather than wash in on which ever wing would have the desired trim change.

Its not likely that you will break anything unless you get very heavy handed. But do keep the heat gun moving to avoid burning holes. This technique is really rather easy to do and effective on most open bay wings but ya just need a little help.[8D]

John