I successfully devalved a little propane tank today, the kind they don't want you to use any more. I bled it off for a couple of days, with the tank set at the top of a largish sloped driveway so the gas would run down the hill and diffuse. When it finished hissing I turned it upside down with the valve open for a few hours. Then I took it into the shop and plumbed an air hose to it and pressurized it to 120psi and vented it, then repeated the air venting twice. I tried to get the valve to admit water but it plain didn't work. I cobbled up a chain clamp setup like Ted Edward's, heated the threaded area with a handheld propane torch until the paint barely started to smoke, and turned the valve out easily with a large crescent wrench.
It was a lot easier than I'd thought it would be based on all the horror stories. I filled it with hot water and a little dishwashing detergent for a first cut at de-stinking it (I don't much like the garlicky smell of methyl mercaptan). If anyone has any bright ideas as to how best to get the stink out of the tank I'd like to know about it.
I'm going to make a little forge.
I cut them open with a cutting disc on a grinder after the water routine. I leave the water in when cutting . The smell was gone from the two halves after about a week. They make nice planters :')) Randy
HEY, I ain't afraid of nothin but you guys are scareing me. At a certain percentage of fuel to air it becomes self explosive. Somthing like 20 to 1. If you wanted to purge that tank an inert gas such as nitrogen or co2 or argon. Definitly not compressed air. Steam is a good purge and used in oil refinery's to prep line for work. The mercaptan is a carcinogen. Get a MDS and check it out. Those tanks are better sent to be recycled the benefit is not worth the risk.
Didn't somebody say that bleach is the correct approach?
jim rozen wrote:
Yep, it worked well for me, after trying a few other things that had very little effect. Bob
I have an old one that they will no longer fill as well, Let me know how to make this little forge if you don't mind. I think I'm getting cabin fever already. It's time for a project!!.
I am making a forge which will be a lot like Ron Reil's freon tank forge which you can see online at http://www.reil1.net/minifor1.shtml although he doesn't give many construction details.
I'm going to be working out of the book "Gas Burners for Forges, Furnaces & Kilns" by Michael Porter. This book has great content but could have used a little editing.
See Matthew Dockrey's forge construction page: http://www.cyphertext.net/~gfish/forge.html
Here's another freon tank forge construction page (very similar to propane): http://fredlyfx.com/freon.htm
And another: http://www.kd5bwd.com/blacksmithing/bs_freon_tank_forge_2.htm
Don't miss Jason's forge in the dropbox: http://metalworking.com/DropBox/_1999_retired_files/ftmf.txt
that oughta get ya going -- Grant
My domain is tinyisland.com - if you poke around there you'll find some stuff I did. It isn't very current. - GWE
Grant Erwin wrote:
Wonder : Think skunk. Tomato juice ? Or Lemon - might be one acid or another...