Here is a large bellows on eBay.. Antique Blacksmith Forge Bellows, 1800's - eBay (item 200386624810 end time Sep-28-09 17:55:35 PDT)
It's located in New York state.

That is about the size of the two stage bellows that is on the forge cart that I use at the historic site. Looks like it would be a nice one to have. The leather could always be replaced with canvas. That would not dry out as fast.

I would love to make myself a set of those........

The plans in the blueprints section make it seem very do-able.
IMHO, I think it's preferable to make/use new ones than to further degrade an original set of bellows.
Ditto about canvas over leather........A lot less expensive and not as likely to dry out and crack apart.

So 2 stage bellows use a chamber to inflate another chamber that blows on the forge? Or do I have this all wrong?
Phil

no i think its a double action, as one side is blowing into the fire the other side is inflating, and then vise versa. twice the air for half the work. at least thats how ive seen it work.

I read something different somewhere, but might have misunderstood. I have only ever seen what you described, one blow, one fill, then the other way.

How much volume would a set of bellows need to drive a brake drum forge? Is there a guide for bellows vs fire size? Kicking ideas around...

Phil

That looks like a small tyre roller on the bench behind the bellows, they're really useful.

I passed on a set like that at a flea market/antique show this summer for $50......man, I'm stupid, in hindsight!

Phil, the Bellows that is on the forge cart that I use is set up so that when I pump the handle, air is forced from the bottom section into the top. The air then inflates the top section and also starts blowing into the forge. It continues to blow until the top section is deflated. If I am heating a heavy piece of metal, I have to pump the top section full and keep it pumped up as long as I need the heat. I hope that I explained that so that it can be understood.