I wonder... does the film shrinking and tightening as it cools tend to warp thin balsa fins (larger ones would be especially at risk). I just wonder if that's an issue with shrink film coverings and maybe the reason it isn't used more in rocketry?? In model airplane use, the wing spars and stuff would actually strengthen from the shrinkage, making a stressed-skin type structure...

Later! OL JR

__________________
The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round!

Great example!

Doug

.

__________________
YORF member #11

That's pretty much how I see it. The few airplanes I've seen built this way are just as you describe - shrink wrap over the balsa wing structures (in place of tissue), and the plastic seems to give the thing lots of strength.

Doug

.

__________________
YORF member #11

MonoKote does not work very well on inside corners or compound curves. There is a one page article on page 10 (page 12 in the PDF) in the January 1969 issue of Model Rocketry Magazine. I am surprised that Japanese Tissue/silkspan and dope method for strengthening fins does not pop up every so often.

__________________
'Til next time,

Mike Toelle

NAR 31692 L1

SAM 0373

I have always had good luck with the Avery lable paper. It can wrinkle a bit if it gets too wet with glue or paint but mine has always dried back to a flat state. With a little CA all of my edges have stayed down nicely. Never have had it come loose from the balsa. Even stayed on after a crash with the balsa crushed underneath. Works great with squishy, weak balsa, just make sure you press it down nice and tight and bang! . . . instant poor man's plywood. I can only dream of Baltic Birch on my budget.

A bulk box of 100 sheets goes a long way, so for a light, easy, strong, and cheap system it is hard to beat. It will absorb a little more primer on the first spray but I have had no trouble lightly sanding it. It will take a bit more paint and number of coats to get a smooth finish. For really high end finishes it won't work, nor is it the best to wrap around edges, the other paper/glue combos work better for that. The 3M stuff was on sale so I will try a box of that, you even get another 25 sheets!

Great info here.

Don't get me wrong, lite-ply and basswood have their place, but then again, for a lot of things they're overkill... All depends on what you're trying to do.

Best thing I've seen done with plywood is making body tubes...

Later! OL JR

__________________
The X-87B Cruise Basselope-- THE Ultimate Weapon in the arsenal of Homeland Security and only $52 million per round!

Agree

Have you met GH? He is too.

__________________
I love sanding.

not yet