Homebrew PCBs

I use a Seelye Electric hot air welder for plastics. There are low 
cost copies of this torch available on eBay. They go for less than 
$50 (US). Air can be used for welding PVC but nitrogen is used for 
almost every other type of plastic. You will need a tacking tip and a 
plain round tip. Another tip to consider is a speed welding tip which 
feeds the rod and welds at the same time.

I rigged up a valve that switches the torch to air during warmup and 
when idle. The nitrogen is switched in when welding. This conserves 
the nitrogen supply. The air and gas pressure is regulated to about 2 
PSI. 

I use nitrogen for all plastic types including PVC because it's 
easier to prevent charred edges and burning. The cleanest welds will 
always be made when using an inert gas. No amount of gluing will ever 
equal a properly welded joint.

Tom