So puttng the plane in the sun 1) before shrinking tight on the initial covering job -o do you mean 2) when you notice sags after covering /shrinking and its been a bit of time.. will soften the coverinng before re-shrinking it tight with the gun and this gives the best results Do I have that right??... and is it the first or second case.

I live in Tampa where humidity is second to none during the summer and store my planes on racks in the garage. Have not had a problem covering sags described above but I will get a small amount in corners and things that like that. It seems to me anyway that ultracote fairs better than monocote.