Bottom blast tuyere

[PapaDooks]

don't even know if that's the right name for bottom blowing or not but i was wondering if exhaust pipe was "safe" to use for this purpose? would i need to de-gal it first if it was galvanised piping ?

[turbo7]

If it was gal pipe mate I wouldn't use, not even worth the risk.

[JHCC]

Or chromed. Especially chromed. 

[Frosty]

I made mine with plain steel semi truck exhaust pipe I took out of the scrap pile at the heavy duty shop. It works beautifully in both senses. It made an excellent tuyere AND it's easy to work with.

I used 4" for the vertical section and 2" for the horizontal supply. Matching them to weld is as easy as buying a 2" hole saw blade. I just drilled the 4" pipe where I wanted the supply to enter, IIRC about 3" below the air grate and 6" above the ash dump. I had a brainstorm and instead of trying to mark and cut the 2" to match with a jig saw I clamped it in my V block on the drill press and used my 4" hole saw. 

Once again I used the 4" hole saw to cut the opening in a piece of 14ga. to serve as the mounting flange under the forge. Then I just mig welded it all together Oxy acet welds are easy peasy on exhaust pipe as well. For the last bit of construction I stuck it against the bottom of the forge and drilled 4 screw holes. The air grate just lays over the tuyere and mounting screws.

The ash dump is a semi truck exhaust flap cap clamped upside down on the bottom. The counter weight is aimed at the operator position so it's easy to give it a flip open with a hammer, tongs, piece of stock or anything almost a foot long, say 20cm.

That's it, easy peasy and works a treat.

Frosty The Lucky.