stx44 wrote: how do you cover them without warping the airframe? Are they covered with normal tissue?
Hi stx44,
The answer to NoCal warp control is in tissue preparation. Basically the tissue is prepared in one of two ways:
(1) It can be pre-shrunk with a fine water spray or steam on a simple frame, or
(2) It can be wadded into a tight ball like a candy wrapper, then carefully opened and smoothed out as best as one can. Some modellers prefer to iron it but this step is optional.
It is usually glued to the airframe with a soft glue stick or diluted white glue (PVA). The tissue is carefully laid in place and smoothed out as much as possible, then the covered part is put aside to dry completely.
At first the temptation may be great to smooth out any wrinkles that appear as the tissue is drying, but don't do it!
. You actually want a bit of looseness in the tissue to accommodate temp. and humidity changes that otherwise could warp the lightly built airframe.
NoCals are normally covered with either Japanese Esaki or domestic tissue but I have also used cheap craft tissue. Biggest issues with the cheap stuff is that the colors can rapidly fade with prolonged sunlight exposure, and also the colors often run when wet. Used to use steam to pre-shrink it but now I'd use the crushed method and lightly spray each side with a rattle can clear acrylic (like Krylon) to make the tissue more water resistant.
Hope this helps
,
zoomie