I've had a hankering to try some simpler blacksmithing projects like a trivet or squirrel cooker. So I thought I would make a simple forge to take to the Suffolk bushcraft group permission, where a few of the other guys have an interest too. So, an hours work with my angle grinder, powerfile and welder, I have a forge that looks usable. Do any of you guys know what thread the gas fitting on these bottles is? I need to make up some kind of bellows system to attach to the under side of the forge. I also have 30" of rail that I can cut to make an anvil. The bottle was emptied and cleaned last year, Thanks for looking.