Hi fellas, I just did a search for " freon tank " with no results. I wonder if it is safe to cut the ends out of an empy freon tank with an abrasive wheel? Also I found a local sourse for insulation sold under the name of "Home Saver" Flexi-wrap. the box didn"t have a heat rating on it. It is 1"x 24" @$4.25 a linear foot. any input on these issues would be appreciated.

I have been wondering this myself

Hi Guys

I have made a number of forges from used "freon tanks" no problem, I suggest:

1. Open tap fully in ventilated area to make sure all gas exhausted
2. Cut to your hearts content, angle grinder worked for me.

See next post. Read the safety warnings there

Any insulation that's meant for the home is going to turn into glassy goo well before it reaches any serious forging temperature. You could possibly use something like that for additional efficiency if it were outside a couple layers of something like Kaowool or Inswool, and protected from direct contact with forge temperature flames. [Later: OK, maybe not. This stuff is for insulating chimneys, and some of those have pretty reasonable temperature resistance. But I wouldn't buy it without knowing for sure. Contact the manufacturer and ask about the maximum continuous service temp for this stuff. I haven't been able to find it.]

Freon will convert to phosgene gas if it gets hot enough. Very bad news. They used phosgene as a chemical warfare agent in WWI. See here: http://meeting.chest...ract/136/4/9S-c Perhaps not a problem with abrasive wheels, but it'd still make me nervous if I wasn't 100% sure the cylinder was totally empty.

Before cutting any suspect cylinder I punch a small hole in the bottom, open the valve, submerge the cylinder upside-down in a drum (or garbage can) full of water, and let the cylinder fill completely until there are no more bubbles, even when I wiggle it around a bit.

Thanks for the replies fellas. I found another stove shop locally that sell Kaowool. Is kaowool all the same or are there different grades / temp. ect.?

I'll take your advise onsubmerging the freon tank Matt, better safe than sorry.

As long as we're talking about the blanket, I think the standard grade is rated to 2300 F, and most folks seem to do fine with that, especially with a thin liner of some kind of castable refractory or refractory mortar. There's a grade that's rated to 2600 F, but it's less common. The guys you buy from should know the temp rating, or should be able to find out for you.

There are different grades. The 1300C (2300F) is 8 pound is a good choice, but propane burns hotter. With a good coating that will last quite some time.

Phil

I used 2300* rated Insboard for doors on my blown gasser and they melted I believe my Inswool is rated for 2700* or higher and I have a 3200* degree rated mortar over that. It does fine except there's a depression where the burner flame first hits the refractory. This, however is an exception as I have a pretty big burner for the forge (1.25" pipe in a 6" x 15" chamber) and it gets crazy hot and my naturally aspirated freon tank forge (lined the same as my blown forge) doesn't seem to get near as hot even though I can achieve welding temps in it.

Scott

Footnote:
The doors didn't melt completely; Just where they were exposed to the inside. Melted a depression the shape of the inside of the forge. I coated this with the same mortar used over the wool and they seem to be holding up but when I replace the doors it will be with a higher temp rated material. Bottom line: IMHO, 2700* is the minimum temp rating that should be used; especially if it is going to be used to weld in

Thermal Ceramics (the Kaowool people) make a 3000 degree blanket called Maftec, but I haven't figured out where to buy it. I bet it's spendy.

I got the best price from larkin , I got the 2700 degree
send them an email and tell them what you want. they were really great to work with.

http://www.larkinref....com/index.html

i also got the stiffener with that. BUT I still am using my old furnace and have not built the new one! I also got some zirconium and different clays to make the coating., I got to get going. hope you get yours going faster than mine!

Thanks again for all the help folks. I haven't even started yet though, still researching when I have time. I ran into an old friend in August who sold me an old 15'x48" clausing lathe for a song and I've been making room in the shop for it and rebuilding it ever since.Hope to build a forge one of these days.

This guy used an angle grinder cutting wheel on a freon tank. You may find some useful info here.
http://www.iforgeiron.com/topic/23341-bp0915-freon-tank-extended-forge/

Thanks moderator 19, I read his thread the other day. I think he ended up downsizing though due to gas consumption. I ordered a book last sunday called Atmosperic forge and heat treat oven, or something like that. It still hasn't arrived, I'm kinda anxious to read it.