rubber powered planes and the cold

: Does anyone here know anything about rubber and the cold? : Does the cold ruin the elastic bands (TAN II and such)?

Back in the old days we (flying F1B wakefield, the FAI rubber models) were allowed to use heaters to warm up the rubber before flight. Then they were banned, so now we have to fly with cold rubber (even though people tend to keep the motors in the pocket to warm up a bit, but then the motors cool off when inserting into the model anyway).

Cold definately cuts down the power output. Down until 0 degrees centigrade you can fly pretty much as usual, but below that be prepared to see reduced torque when unwinding. At -20 centigrade the rubber is pretty stiff, and torque is down so that you get maybe 2/3 of the altitude that you would get on a summer day. The initial torque is almost the same, but it drops down real quick. The cold does not ruin rubber though, just cuts down the tq.

Just for your information: here in Finland we fly most of our contest in February-March on frozen lakes, in the summer the fields are too small for flying (forests everywhere!). So we have pretty much eperience of using rubber in the cold. This winter has been awful though, temperatures have been 5 to 10 C over average, lakes are barely frozen, contest get cancelled as lakes are unsafe to walk on. Damn climate change!

-Tapio-

What if the rubber is in say 20 below (C) for a while. Does that harm it?

: What if the rubber is in say 20 below (C) for a while. Does that harm it?

Some people store their rubber in freezer to slow down ageing (Tan II exists no more, and newer rubber is not as good in energy return, so Tan II is getting more and more valuable as time goes by, provided that it is stored properly). They claim no ill effects from freezing. On the other hand, I store my stuff in room temperature, in original cardboard boxes, and the tested energy return of some 6+ years old stuff has not degraded, so I doubt that freezing would be worth the trouble. Anyway, exposing the stuff to freezing temperatures does not seem to harm it.

-Tapio-

Tapio,

Thanks, I was worried that my rubber was harmed when it was transported in our Canadian winter temperatures.

Looks like we're ok.

Darcy