Dangers in Keggle conversion?

I recently took some classes in welding (in order to start making my own brewing equipment) and the teacher was talking about how it can be dangerous to use a plasma torch on old wheat drums, because they can explode. Later I asked him about whether he thought it would be ok to cut the top off of a keg, and he said that it could really be dangerous.
Is this guy wrong, or are the hundreds of people i hear about making their own keggles risking their lives?


Here's a link to some info on this...http://www.docep.wa.gov.au/worksafe/Content/Safety_Topics/Hazardous_substances/Additional_resources/Empty_drums_-_potential_bombs.html

SweetSchalls said:

I recently took some classes in welding (in order to start making my own brewing equipment) and the teacher was talking about how it can be dangerous to use a plasma torch on old wheat drums, because they can explode. Later I asked him about whether he thought it would be ok to cut the top off of a keg, and he said that it could really be dangerous.
Is this guy wrong, or are the hundreds of people i hear about making their own keggles risking their lives?


Here's a link to some info on this...http://www.docep.wa.gov.au/worksafe/Content/Safety_Topics/Hazardous_substances/Additional_resources/Empty_drums_-_potential_bombs.html

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As long as you remove the stem or open a hole in the top of the keg so pressure can't build up in the keg while you're starting to use the plasma cutter, you'll be all right.

Enough said.

Now, after you get the top off you should make sure that the bottom lip where you will be applying the heat is not sealed. Some kegs have holes some don't. You would want to cut some holes in there if the later is the case. The ones that don't could possibly explode.

There was a thread about this happening, but I can't seem to find it.

drill a hole in the top to let out the expanding air. apply plasma, have perfectly round hole.

Donasay said:

drill a hole in the top to let out the expanding air. apply plasma, have perfectly round hole.

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You don't have to drill anything if you just remove the sanke valve.

With so many ways of ensuring no pressure build up, the doomsday warning dude is way off. You can even tap a 10 penny nail or screw driver between the ball and seal in the valve. You can remove the valve. You can drill a hole. No danger unless the operator is a complete tool.

Beerrific said:

Now, after you get the top off you should make sure that the bottom lip where you will be applying the heat is not sealed. Some kegs have holes some don't. You would want to cut some holes in there if the later is the case. The ones that don't could possibly explode.

There was a thread about this happening, but I can't seem to find it.

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Here ya go: https://www.homebrewtalk.com/showthread.php?t=41422

Your teacher wasn't completely incorrect in his statement that cutting a keg COULD be dangerous, but I think he led you down the wrong path as to why. With a few simple precautions, cutting a beer keg is a very simple, safe task.

The overarching issue with flame/plasma cutting a tank isn't simple pressure relief, it's explosion due to the tank's residual contents. In the case of a beer keg, the residual contents are not flammable at all, and there is no risk of explosion. In the case of a flour barrel, any remaining flour "dust" could ignite, causing a violent explosion (see here). If the tank was ever used for oil, gasoline, flammable solvents, etc, there is an extreme risk of explosion, and it's highly recommended that a professional handle a job like that.

However, when dealing with a beer keg, it is ABSOLUTELY ESSENTIAL to relieve pre-existing pressure before cutting, or you could be faced with a face full of hot slag at the initial cut, and, in the unlikely case of an extreme pressure, the keg could burst as you compromise its structural integrity (note, that's NOT an explosion, but it's still fairly dangerous). However, if the keg is unpressurized, it's virtually impossible to apply enough heat with a cutting torch, especially a plasma torch, to cause any harm. It's a good idea to drill a pressure relief hole or remove the valve before applying the torch, but that's just to avoid a slight slag blow-back when the UNPRESSURIZED keg is initially punctured. Once the initial cut is made, pressure won't build anymore.

Make sense?

One more warning, although significantly less dire. If you choose to relieve the initial pressure inside the keg by depressing the ball of the Sanke valve with a nail or flat-headed screwdriver, make sure the keg is lying on its side. It's not dangerous to do so with the keg standing upright, but you're liable to get a face full of skanky, old BMC. Trust me.

^^^ after cleaning 20 cornies and converting 2 keggles yo'd think I'd had learned that! NOPE. Maybe it was because the 20 cornies had come froma homebrew life and the beer in my face was quite enjoyable.

e lo said:

It's not dangerous to do so with the keg standing upright, but you're liable to get a face full of skanky, old BMC. Trust me.

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Despite the fact that I had read this several times, I was so excited when I was making my first keggle that I hauled the 1/2 full 3 year old keg of Dos Equis out of the bed of my pickup where it had just finished a 20 mile drive, set it on my driveway standing up, and shoved a screwdriver into the ball. I truly wish that I had a picture of my face as I did so....

IrregularPulse said:

^^^ the beer in my face was quite enjoyable.

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A whole new brand of "Golden Shower"

I did it in the kitchen. SWMBO was really PO'd about the vinegar/stale beer odor that hung around for 2 days...

I just about got a face-full myself earlier this morning. Luckily I thought a second time before simply depressing the ball valve and just installed a sanky tap with the dispensing fitting capped and the one-way seal removed from the gas input. The contained pressure just hissed out of the gas port when I engaged the lever, and I drilled a small hole in the top of the keg to keep it from self-pressurizing again before I had a chance to cut it.

I'm sure it's been stated but I'll re-state it. As soon as you ignite the torch, the vessel is punctured and can no longer build pressure. To think that in the instant before the torch cuts through that it could build up pressure from the heat is just totally unrealistic. At that point, your only risk is releasing any pressure that was already in there which you should have taken care of only moments before by shoving something in the ball valve for a second or two.

I just started grinding, when the grinder penetrated the top I heard and felt a whoosh of air but no explosion!!!

Linc