You may be better off asking on one of the American model engineering forums as we don't have that many members from the US where the PMR and Mid West products are far more common. Try MEM forum for a start and also HMEM.

Not sure where you are located but check the local boiler regs, I doubt it makes much pressure but it may not be allowed as it has no safety valve that I can see!! Its possible that they use the silicon tube as the safety expecting it to blow off if teh pressure gets too high. So likely to be quite low pressure similar to Mamod

Don't see any reason why you could not use meths

Its copper with a brass fluetube

J

Edited By JasonB on 10/04/2014 07:54:12

I was going by the instructions for building the boiler, all I can see is a filler cap and an outlet stub which takes the silicon tube.

You may also find it a bit wanting in the amount of steam produced for your engines, wht not try the PMR vertical.