I don't see a lot of good said about these but for 2 - 30 packs of beer I had to bring it home.

Last night I was talking to the guy that gave me the anvil about looking for a forge now and he mentioned 

that his brother had a propane forge he didn't want. It was under a 4 foot pile of crap in the back corner of his shop

and covered in 40 years of grime. We made a deal, loaded it up and this morning I pressure washed it and made a

fire in it for a few minutes to warm the bricks to evaporate any water. 

Is there anything I should know about it before I try and use it other than it is a fuel hog?

thanks for your help you folks seem like a good bunch.

Where worked, they used one to heat 1" - 1.25" plate before it was bent in a press brake, laid across the opening, it took 8 to 10(?) min to get dull red. Never explored using inside to forge with. Gas hog; yes. Two 30s? Good trade imho

I am wondering if an insulated dome lid with a hole in 1 end would keep in the heat better and make it more efficient on fuel

I have effectively the same machine which I haven't yet run..and don't really intend to.  What you have there is 2/3 of a killer ribbon burner forge.  Re-route the air/propane mix line to a ribbon burner in a mailbox-shaped insulated enclosure that sits on top of the "trench", dropping some fire bricks into the trench to make a complete hearth.  For very little extra past what you've got, you'd have a more fuel efficient system that puts out heat like the fires of Hades.  

No, I haven't done this yet to mine...still planning.  I figured I might get lucky and have you work out all the details and discover the pitfalls for me  

What you paid? Heck, you could probably resell the blower portion, throwing away the rest and still come out way ahead--by the end of the day on a good day.

I have a Johnson Appliance 122A, can't tell the difference by looks I haven't lit, ever. My thought was to pull the hard firebrick liner and replace it with insulating refractory and face it with high alumina kiln shelf and see if it'd be a less a gas hog and hit a higher temp. We had one in high school shop class and it wouldn't hit but low yellow which wasn't such a bad deal the shop teacher hated lighting a forge for many valid reasons.

I'd be happy if someone would like to come get mine.

Frosty The Lucky.

I like Kozzy's idea and analysis of what you paid.  Otherwise you should run the numbers on fuel ($$) versus production.  Not really for hobby use, do you need to have 20" of 2" square or 20 pieces of 1/2" round hot at once?