Hi all, I signed up here years ago then drifted away. Having recently rediscovered the wealth of information here, I'm thinking about having a crack at building a 3/4" propane burner and a forge from an old propane bottle... Now my background was more welding than blacksmithing as a Metalsmith in the British Army (mostly welding, but a bit of sheet metalwork, milling and turning too with a little bit of forging now and again), but I'm no longer doing it for work and I want to keep it up as a hobby.
So here goes... Frosty since it's your design this is primarily aimed at you. I'm thinking about using stainless (316L) fittings for the T, the mixing tube and using a inch to 3/4" reducer as a flare (I'd turn a pretty tapered flare but can't afford a lathe of my own yet). These would all be butt welded together rather than threaded, which obviously reduces how much the length can be tuned without serious work. I was planning on using a 1x3/4" reducing tee, so then having 6" of mixing tube based off the ratios in your plans, but I'm unsure whether a) the flare is even necessary or b) if the flare counts towards the overall length as with it being around 2" long, that then extends the mixing tube and welded flare out to 8"? Having never built a burner before I'd love to hear some opinions, whether it's been tried or not etc. The rest of the burner (contact tip, brass fittings and copper fuel lines etc) was going to remain the same.
I've hopefully dropped in an example pic below of the type of joints I'd be looking at using (obviously with just a straight pipe butt welded between them), but 316 for it's added corrosion resistance rather than the 304 shown. My thinking was the smoother transitions between tubes would be the main difference between this and your original burner, but having read far too many pages of burners 101 and not even reached the end yet, I think I've confused myself as to whether it would be beneficial or not.
The forge build itself is probably a story for another discussion, but I'd been contemplating cutting a ring out of the middle of the propane bottle and then re-welding the two ends together. Essentially making a very stumpy bottle with cut outs in the sides, and the burner entering more or less through where the valve would have originally sat. Then following all the other general advice of two 1" layers of ceramic wool lining, rigidized and heat reflective coating of some sort to reduce the volume down to around 300 cubic inches (ish).
Hopefully none of this sounds too stupid?
Cheers,
Matt
