I've successfully built one burner brick with metal frame forges and now am working my first 2 burner 20lb propane tank. Typical two 1" ceramic blanket build as I want this to be lighter weight and somewhat portable. I have a large quantity of Satanite and no Kast-o-lite and I'd rather use up what I have and not purchase more product. Most of you seem to be recommending Kast-o-lite now and I'd like to understand why.

Do I have it correct that both will work just fine as a durable liner (the floor will be thicker than the walls and flat with bubble alumina, Martikote on the top) but that the satanite will end up acting as more of a heat sink? Which might end up being a good thing? Using two Matthewson burners. I have been using one of theirs in my brick pile and am very, very happy with it.  Also, general critiques welcome.

This will be my primary gas forge (until I make a ribbon burner) and will be both for shop use and occasional travel for demos. 

 

If you have Satanite use it, it's a good product. The shift to Kastolite 30 recently has more to do with it being a bubble alumina refractory, the bubbles are evacuated silica spherules as part of the aggregate, lightening it and increasing it's insulating value. High alumina makes it resistant to common welding flux erosion.

They're both good stuff.

Frosty The Lucky.

I think I have more bubble alumina than I need for the floor. Could I mix that up in the satanite too or is that wasteful overkill? Any experience there?

Nothing prevents you from layering two different refractories, but mixing them together could be dicey.

OK. I won't mix. Pictures and operational report to follow. When I can get around to it!

We built ours using two 1 inch rigidized layers of Kaowool, a 1/2 inch layer of Satanite and a 1/4 inch layer of bubble alumina with enough to flatten the floor. It has held up very well after 2 years and reaches welding heat in no time Here is the thread if you care to look.

 

I finally finished my first propane bottle forge. Two 1" layers of wool, home made rigidizer, several layers of satanite built up to 1/4" or maybe a little more, bubble alumina floor about 1/2", and topped with 1/8" of Matrikote. I have some high alumina kiln shelf that I cut to size and will use it on the floor also. It is running with two mathewson burners which I can run from 20psi (but why?) down to about 4psi. It heats quickly running it at 10-12 psi. I think my average forging psi will be between 5-7psi and will back off to one burner for small stock. It looks like it will forge weld running around 12psi or so. I am going to borrow a temperature probe to get a better sense of what is going on.  I still need to build a stand and put a front door on it.

I went through the curing process patiently and I have run 5 or 6 full heat cycles and have no cracking. I'll see how this holds up and then start planning a ribbon burner. I used wool because I want this to be portable,  but I think on the next one I will make it from Kast-O-Lite.

Looks good, I like it all round.

Frosty The Lucky.

You will find that combination will work very well. We built our forge the same way. A 20 pound propane tank, 2 1 inch layers of ridgized kaowool, a half inch of Satanite and then bubble alumina all around over the Satanite. The only difference is the burner, ours is a single burner Gaco kiln burner and it reaches welding temp in no time.

20 pound propane tank forge in progress - Gas Forges - I Forge Iron

PS. My first propane bottle forge is working great. Door is on and I am welding just fine. I wish I would have built it clam shell style so anyone making a bottle style might consider this. It was a fun learning process and there definitely will be a next time! But with a blown ribbon burner.

Never used a clam shell forge have you? You can feel the radiant heat from the opening in yours Yes? Just imagine opening the top half and exposing yourself to a couple square feet of yellow hot IR source. 

I thought it sounded like a great idea but have stood within reach of large red hot objects and do NOT want to be that close to yellow heat. 

Frosty The Lucky.

I finally got around to building a stand with scrap lying about. I have transported this forge 3 times now and it has around 100 heats on it. No cracking. It was a great learning project.