Helium tank slack tub and quench tank

[JHCC]

A little while back, I got a party balloon helium tank that I'd originally planned to make into a gas forge. However, I ultimately decided to stick with solid fuel and make the tank into a slack tub. I'd cut the top off and stood the tank on end in a brake rotor that gave it a bit more stability. So far, so good.

I recently got another helium tank and the aluminum frame from an old speaker and thought they might be good for a more stable slack tub. This time, I cut the bottom off, cut the carrying handles in half, and bent them around the frame to hold everything securely.

I added a double layer of hardware cloth inside, to protect the bottom a bit and catch wayward dropped workpieces (below left).

I had kind of hoped that the valve would allow for easy drainage, but I guess gas valves don't work so well for water. No big deal.

I then decided to convert the original slack tub into a tank for oil-quenching. I took its old top, cut off the valve, flattened the handles, and put it inside to protect the bottom from dropped pointy things (above right). The cut-off bottom from the second tank went on top as a tight-fitting lid (below right). I'll put a hinge on this at some point, to make it easier to flip closed in case of a flare-up.

 

I also plan to attach the quench tank to the brake rotor more permanently, to improve its stability. Not sure what to do here: might run a bead of silicone around it, might see about spot-welding it in place, might weld some bolts on the bottom of the tank to match the bolt holes on the rotor. I'm open to suggestions!

[Daswulf]

I would be a bit concerned that the tank handles might not hold it to the base safely enough. But if it's just for water it isn't That big a deal. 

For the oil tank I would tack weld it to the base. I wouldn't trust silicon. Be careful tho, welding thick metal to thin metal can be tricky since the tank metal can burn through before you get good penetration on the rotor. You will want to keep the bead mainly on the rotor and just catch the tank. Do shorter beads like one inch or even half inch, skipping enough space to not overheat the tank metal. And deffinately thoroughly check for leaks after. 

Welding studs to the tank might not be bad, just make sure they are snug as to not wiggle and break around the weld but also not too tight as to stress around the weld on the tank. 

[JHCC]

The handles aren't weight-bearing, but are just to keep the bottom of the tank from shifting around on the aluminum frame. They do that pretty well, so far.

Thanks for the pointers on welding. I'd been thinking about the difference in thickness potentially being an issue, and keeping the bead mostly on the rotor makes a lot of sense. I think I'd rather do that than weld on the studs. Still thinking....

 

[Daswulf]

Free is good, don't get me wrong, but I like something a little more secure and movable. I am using a deeper ammo can for quench oil. I'd have to look what kind it is when I get home. But it has enough volume for the size of the things I need to quench in it and already has a flip open ( or off) lid with a water tight seal making it easy to pick up and move out of the way when I don't need it. And even if it got knocked over with the lid on it won't spill. It cost me about $20. But it works for me. Just a thought. Any army surplus stores around you? 

All in all if you have a dedicated spot for it or can move it easy enough yours should be fine. 

[JHCC]

I like the deep ammo can idea, but given that I've got one kid in college and another in Catholic school, if I have twenty bucks to spare on blacksmithing, it's going into coal and steel. I'm going to keep storing the (canola) oil in the freezer to prevent it from oxidizing too much between uses, so the tank isn't going to be sitting around full of oil. It just means that I won't be borrowing the pasta pot to use as a quench tank.

[Daswulf]

Understandable. No problem. If it isn't sitting around full then you should be fine with your setup. I know all too often things can get bumped into in my shop. Maybe some handles welded or bolted on to help move/ pour it. Or a metal spigot down low To empty it most of the way before pouring off the rest. 

[JHCC]

I'm thinking of making the hinge as a long strap that would go over the top as a handle for the lid, the hinge knuckle itself at the edge of the lid, and then down the side as another handle for emptying. 

[ThomasPowers]

So when there is several feet of flame you grab the handle and move your hand through the flame to close it?

I'd suggest a handle you can just flip over the lid with the tongs...

[JHCC]

27 minutes ago, ThomasPowers said:

So when there is several feet of flame you grab the handle and move your hand through the flame to close it?

Of course not.

27 minutes ago, ThomasPowers said:

I'd suggest a handle you can just flip over the lid with the tongs...

That's the idea; something like this:

(with apologies for the lousy drawing)

Ideally, I'm thinking that the hinge would hold the lid open just at (or just beyond) the balance point, so that it could be knocked shut with minimal effort. The top handle would be for opening, not for closing. The handle on the side would be for emptying.

[Jon Kerr]

Hi John,

How did this go in the end? Any final photos?

Any tips for safely cutting open the bottle? I might copy this but don't want any explosive decompression.....

[JHCC]

Still using the tank with the aluminum frame as a slack tub, with no issues. I’ve using a stainless steel stockpot for oil quenching. Thinking about an outer container that pot could go in, to accommodate spillovers.

Party balloon helium tanks come with a built-in needle valve that can be opened to allow the tank to fully vent. Once the pressure is relieved, that valve can be removed with a wrench and the tank cut safely. Helium isn’t flammable or explosive, so sparks from cutting aren’t the issue they would be with, inter alia, propane. 

[Jon Kerr]

Awesome, thanks very much.

[Ranchmanben]

Jon, stainless beer kegs can easily be had for free. Call your local beer distributors and ask if they’ve got any kegs they need to get rid of. When I did this I got 4 kegs and a 6 pack of beer that was “dented”. 

[Frosty]

I know I've talked about my oil quench tank before but once more unto the thread or block the subject with our dead English grammar. (sorry, a book I'm reading keeps sticking in my head)

My oil quench tank is a 15 gal. grease barrel with a removable lid that is held on with bent tabs. You see them in lube shops, holding grease, transmission/gear oil, etc. I have a piece of 1/4" expanded metal on long 1/4" rnd. stock handles. The handles hook over the side or I can flex it and they slip into the tank and stay above the oil so I can fish them out. This prevents pointy things from poking holes in the tank and lets me clean dropped bits and pieces out without having to drain or reach in with my hand. The snap on lid keeps stuff from falling in when I'm not using it and serves as fire prevention. I tacked a tab on top I can grab with tongs if necessary.

That's the oil tank. It lives in a cut down 55 gal. drum to contain boil over and also has a lid to smother fires. I've never had a boil over, the 15 gal. tank has more than about 10 gal of oil which is enough oil nothing I'm hardening will boil it over. Still, it has a double lid fire suppression. 

All the cutting I did on the drum was with a saber saw and I knew for sure what was in it, 55 gals 10/30 Delo motor oil so I could've used a cutting torch with minimal danger but a saber saw makes a cleaner cut. 

Oh, the 15 gal. grease barrel held Chevron Avimotive grease, the red stuff. 

Yeah, I don't cut drums or barrels without knowing exactly what is in them or doing some serious flushing. I don't like the idea of standing net to an exploding object. Just not my style.

Frosty The Lucky.

 

[JHCC]

Update: the first helium tank became a super-sucker for the forge, and the second is on its way to becoming a gas forge after all. A coworker gave me a beer keg she'd found in the garage of a house she just bought, so that will be the new slack tub as soon as I get the top cut off.