Will cutting brass with steel cause a spark?

[Flogger]

I make vacuum pumps from pipe fittings and weld a 1" bung off to the side. Put a dip tube in one hole and the vacuum pump in the other. Makes an excellent oil change container and with a couple of valves you can extract oil from an engine and blow it back out into the waste barrel. I have made them with 20 pounders for small engines and two 100 pounders on a cart for larger equipment. They will collapse hydraulic tanks if you get carried away.

 

[JsJs]

Safe and easy
1) connect to a BBQ and make sure its empty
2) unscrew the valve to remove it
3) rinse tank with water, dump, refill to overflowing, dump water and use now

 

[NotSoMeanJoeGreene]

I have some old propane tanks I would like to get rid of but they have to be opened. I am thinking of cutting the valve off with my Sawzall, but really don't care to blow myself up.
Another option is to perforated them with my .308, but that may not go as planned either.

Thank you

brass+ steel no sparks, but steel and hidden steel would spark. Lead through steel no spark, just be a good 5 yards to prevent propulsive gasses to dissipate before the lead projectile punctures the steel casing. Alternatively silica based abrasive will not create sparks either. Note in all instances any remaining pressure will release upon puncture, further any ignition will seek the path of least resistance.. so secure the tank well to prevent a jetting effect in case of unexpected event.

 

[Charkmapman]

Our local scrap recycler employees called them "Chicklets". they would throw them in the metal shredder and BOOM. cleaned the teeth. Good fun till the neighbors started to complain....

 

[4Liberty]

I had a 100lb tank, put an open fitting in the valve and vented it slowly for a week, then unscrewed the valve, filled it with water and saws all in half. But really I’ve shot a few and no booms, that blowing up tanks with rifle rounds is movie stuff. There has to be an ignition source and I don’t think a copper jacket lead core round is likely to be enough for boom.

 

[Kenduro]

So couldn't one just turn the tank upside down, open the valve and drain it?

if they have a dip tube, tthat won't work. you'd have to remove the valve. Isn't it threaded?

 

[AnotherBueller]

I witnessed a motorcycle repair once regarding a gas tank: it was filled with water to dissipate the fumes and then welded. Once complete, it was drained and dried.

VERY old school method. Much older than me.

 

[SPM]

how do you turn a small propane tank into a air pressure tank

Neighbor made a portable air tank for me, many years ago and it came in handy more than once. Used it for an air nailer/stapler or just to top off a low tire. It's easy to refill with air and even has a gauge.

 

[nknelsen]

If they are the 20 lb type, put a long bar through handle holes and use a 24" pipe wrench to unscrew valve. I don't recall if it has Left Hand threads or not.
Filling with water is time consuming and does not guarantee there is no flamable gas still in the tank.

It's a reg ¾" NPT threaded valve. Filling it with water takes 30-60 seconds. And yes it is the best and safest option. I've spent a good portion of my work career dealing with compressed tanks.
A hidden propane tank in a load of scrap steel has killed many people, if a shear on an excavator cuts into the tank the explosion is very violent.

 

[QuantumRift]

I have some old propane tanks I would like to get rid of but they have to be opened. I am thinking of cutting the valve off with my Sawzall, but really don't care to blow myself up.
Another option is to perforated them with my .308, but that may not go as planned either.

Thank you

What kind of tanks?

I had 20 lb tanks and to quickly do this, I removed the valves *with a wrench* and then filled them with water. After a short while I was able to cut them in half with a cutoff tool. Recycle places or trash won't take whole (although empty) tanks here. The water displaces any residual propane gas.