Model Forum / Radio Controlled / Air Models / May 2004

One tip I can give is to pull the Monokote tight as you apply it, especially
over open surfaces.  Another is to use something like Balsarite to seal the
wood.  Balsa is porous, and the air inside it expands and contracts and can
push the Monokote up off the wood.  My planes get wrinkled with age too,
though, despite my best efforts.

Perfectly normal - wood airframes shrink and swell with seasonal
temperature and humidity changes.

When the airframe shrinks in dry weather (heating season), the
covering 'crawls around' on the airframe.

When the airframe swells in the Spring due to increased humidity, the
covering is not where it was in the Fall, so it's a given rite of
Spring to chase winkles outta the moneycoat with a heat gun.

Painted fabric coverings _seem_ to handle airframe shrink and swell
better than polyester films, but you do see fabric covered models now
and then with a bad case of baggy pants in the Spring.

The only covering I've found that doesn't get the sags is fabric
spritzed with alcohol-thinned epoxy before painting.  The Coverite
Super Shrink on my Extra 230 never has sagged and is still drum-tight
after six years.
Cheers,
Fred McClellan
The House Of Balsa Dust
home.mindspring.com/~the-plumber