nickl02,
I just rotate the drill bit manually with my hand. If you do use an electric drill, just run it slowly. It won't take much pressure to cut through it.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I bought a drill bit with an extra long shaft and I just push it down through the foam until it hits the plywood underneath then I turn on the drill.
..... Bob
Beam me up, Scotty, there's no intelligent life down here. (Captain Kirk)
I reject your reality and substitute my own. (Adam Savage)
Resistance is not futile--it is voltage divided by current.
Just use a slow speed and you should be fine. Slow as in not full speed. I don't mean barely turning. I never had a problem with melting foam from drilling myself though. I think because it is not a 'dense' foam the same way styrene is. Styrene has melted on me, but insulation foam never has even on jobsite sites.
So yeah, I would say go for it, it won't melt. Have fun. :)
Ray Breyer
Modeling the NKP's Peoria Division, circa 1943
... and if you are cutting a hole under a throwbar for that tortoise wire, a leather punch (3/8" or 1/2" diameter) works great. It will remove a neat core.
Karl
The mind is like a parachute. It works better when it's open. www.stremy.net
A long thin-bladed screwdriver works well for this, too. Once I get the hole all the way through, I push a drinking straw down into it. This makes feeding wires a lot easier. For really thick foam areas, I made a tool from a thick wire hangar. I made a loop in one end and ground the other to a sharp point. I twist the wire through the loop and pull it through.
Marlon
See pictures of the Clinton-Golden Valley RR