This is part warning to others, part query...
My 2.x laser is almost complete, and I've been doing some test jobs to try things out. While cutting a piece of paper, I noticed some buzzing, and that the laser power was fluctuating. A moment later the positive connection to the tube was in flames and had popped off. I hit the emergency stop, and put it out with the fire extinguisher. Massive overkill (the flame was match sized), but I didn't want to get too close.
I think the problem was the self-amalgamating butyl rubber tape I used to cover the connections (from
http://www.jaycar.com.au/productView.asp?ID=NM2826). While it is supposed to be for high voltages, and able to resist coronas, I found later that it's very easy to set alight! I had assumed that given the intended application it would include some flame retardant additives.
I'm going to try some silicone rescue tape instead, can anyone give suggestions on a particular brand fit for the application, or is the generic rescue tape good enough? Any extra tips on getting a secure, non-flammable connection (using a potting compound for instance to completely exclude air)?