by kittyfritters » Fri Nov 06, 2009 12:24 pm
We've covered (No pun intended.) this topic before. Silkspan is usually found in the kits that are 24 inch wingspan or larger. It weighs more than tissue, and requires more dope to fill, but has several advantages. It is stronger than tissue, and not as sensitive to grain direction when applying. The chief advantage is wet strength and flexibility. If you cover with wet silkspan you can pull it around curves that you would have great difficulty covering with tissue. For example, with a little practice you could cover one entire half of the fuselage of a 400 series model with one seamless piece of silkspan with no wrinkles. When you look at some model designs from the 1930s and 1940s you might wonder how they could possibly have covered some of the concave surfaces on pylons and undercambered wings. The answer is silkspan. Wet silkspan can be stretched and coaxed into these curves and simply pinned down at the edges until the glue dries. Real Japanese tissue, (not domestic wrapping tissue), also has wet strength, but will not stand as much pulling and stretching as silkspan.
I experimented with the silkspan that came in my 400 series Bf-109 and found that I could cover wet with Uhu glue stick. Beats rubbing your fingers in dope or Amberoid. Of course, wet covering requires that the balsa structure be sealed with dope before covering. Also the edges touched by the covering should be as smooth as possible. Any bit of fuzz or insignificant drop of glue on the frame will show through the covering after it dries.
Try covering larger models with wet silkspan. When you have mastered the technique it is quite addictive.