building a propane tank forge

[Lynn Gledhill]

Years ago someone suggested I flush out my 100lb tanks with water prior to cutting them apart to build a tumbler.

Trick is if you can, fill the tank with water. Think about it. Can't have fire without oxygen. Tank is full of water, not O2... won't explode. You can cut under water with a cutting torch. I once had a job to cut a big hole in a waste oil drum... Just plumbed in the exhaust from my truck for 30 minutes and with the truck running burnt the hole out with the torch. No oxygen... no fire... No problem

[Jason brooks]

Lynn's right: no oxygen, no fire.

Well, here's how I ended up doing it:

I took the tank to the airgas depot here in hillsboro and paid a man cash to loosen/remove the valve from the tank. After I got it home, I filled it up with water up to the very top. I drilled enough holes below the water line to allow a sawzall blade in there. Once I got a six-inch section cut out, I emptied it out, and lit a large charcoal fire on the inside and outside of it.

After the tank had cooled, there was no more mercaptin smell in the tank, and I used a cutting wheel to finish the job.

I will post a picture here at some point.

[Jason brooks]

You can buy a "RIGIDIZER" to put on the Koawool to make it stiff. This will let you brush on whatever coating you want to with a higher probability it will stay on. One such product is "INS_TUFF". Google for "INS-TUFF RIGIDIZER" and you will find several sources to buy it (Larry Zoeller may sell it also). You can buy it in quarts or gallons. Take note that if you use this product, you still have to put another covering over it (like ITC-100 or ?) because it (alone) doesn't do well with temps higher than 1600 degrees. If you desire, you could even put a mortar, like T-36 Refractory Cement on the ridgidized Kaowool (about 1/8th of an inch thick) before the final reflective final coat.
Works for me! :-)

Watch out though if you use itc-100: I ended up talking to the owner of ITC and he's very clear they don't recommend putting itc-100 on top of rigidizer. Which sucked since I had already put ridgidizer on the kaowool. I solved it though by removing the first layer of wool, reversing it, and re-inserting it.

-jason

[Dave Hammer]

Watch out though if you use itc-100: I ended up talking to the owner of ITC and he's very clear they don't recommend putting itc-100 on top of rigidizer. Which sucked since I had already put ridgidizer on the kaowool. I solved it though by removing the first layer of wool, reversing it, and re-inserting it.

-jason

I was not aware of advice not to use ITC-100 directly over rigidizer. I have read information saying that ITC-100 was being used over many surfaces, so I assumed it could be used over rigidizer. Do you know what happens when it is used over rigidizer?

Personally, I'm using zirconium silicate, mixed with collidal silica (to a slurry) for my reflective surface. Ins-tuff is collidal silica. I ridigize, then put a layer of reflective, then T-36 refactory mortar (1/8th inch), then another layer of reflective. This process is used by someone I know that works with glass.

I didn't mention the zirconium silicate before because it is not readily available (at least I couldn't easily find it), and it comes with a lot of warnings for use. I'm buying some from a friend that doesn't sell it to the general public.