How old a keg ? Older kegs had a tapered kind of shape to them with a kind of "belly band" in the middle with a side-bung for filling the keg. This side bung was often wood, driven in with press as part of the keg filling at the brewery. Older kegs would be formed from three pieces of aluminum and would have the tapered shape.
Newer kegs are pretty much straight cylindrical in shape.
These older kegs came in sizes called " quarter kegs" which were 7.75 gallons; and "half kegs" which were 15.5 gallons. The little quarter kegs made dandy tanks for the quarter mile dragsters. The half kegs made dandy gas tanks for the street rods. Being formed from heavy gauge aluminum they could be TIG welded to put in a filler fitting (welded into the side-bung opening) and fuel delivery connections. Polished up, they look sharp.
Jim K beat me to the punch about using a beer keg for a mooring buoy. Other uses: if you have got a straight cylindrical stainless keg, cut the top out of it. Then grind the inner walls smooth where you cut out the top. Now you have a dandy quench tank or "slack tub" for quenching work if you do any blacksmithing or heat-treating. If you have a TIG setup, weld on a "boss" (threaded stainless pipe coupling) down on the sidewall near the bottom- this will let you have a good drain cock.
Other modifications: If you want to quench parts in oil, get some stainless pipe or tubing and make a cooling coil. Cut two holes in the sidewall or bottom of the keg and pass the "legs" of the cooling coil thru. Seal weld the tubing to the skin of the keg. Connect to a garden hose and you will keep the quenching oil cool if you are doing a lot of oil-quenching.
Variation on this same idea: use the keg as a settling tank for water based coolants.
I saw a couple of the new style stainless beer kegs modified for use as quench tanks and fitted with cooling coils at the Northeast Blacksmiths' Hammer-In a couple of years ago.
Other ideas: Use the keg as a closed fermenter for something like homebrew, root beer, hard sparkling cider.... To do this conversion, you will need to modify the keg. It likely has the bayonet lock fittings & internal tubing on it for the beer tapping system. These will have to go. You will likely have to weld in some "bosses" (threaded couplings) so you can put on a water seal (to vent off excess CO 2 pressure but keep air out) and "bung faucet" to daw off whatever you choose to ferment. You will also most likely have to steam out the keg to get rid of the residue from the beer.
Bear in mind the skin of a stainless beer keg is pretty thin. Breweries want to get the most for the buck when shipping beer, so the kegs are as lightweight as possible. I would not recommend using a beer keg as any sort of pressure storage tank.
I worked in the old Rheingold Brewery when I was in college. Back then, beer kegs were aluminum and you could get a quarter keg as well as half keg of beer. Lugging a full half keg to a party or picnic was always fun. The old kegs looked cool with their tapered shape but were a b--ch to handle. We used to put them in a stout chair to carry them upstairs. The keg drivers at the old Rheingold Brewery used to put a kind of pad on their shoulders and walk away with a full half keg (about 150 lbs)on their shoulder. Every so often, some unlucky keg driver would open the side-bay door of his truck and get a surprise. These were reefer box body trucks on typically a Mack or White cab-over chassis. They used to stack the kegs all the way from floor to ceiling into those reefer bodies at the brewery shipping docks. The drivers would have a number of stops to deliver full kegs and pick up empties. Every so often, some unlucky driver would open the side door on the reefer box and a full keg would fall out. Usually, the drivers put down a kind of fiber mat or pad to cushion any kegs that did fall out. Every so often, one of those full kegs would hit the pavement hard. Usually, the side bung would blow out and there would be a gush of beer all over the place. The beer in the kegs was already pretty "wild" from being shook up in transit, so it didn;t take much else to blow the side bung. This made a spectacular show of beer suds in the street.
One incident happened when I was working at Rheingold which would be laughable except the two guys involved got hurt pretty badly. Seems they used to send out a keg driver and a helper on the trucks. One day, a keg driver and helper stopped at a neighborhood tavern to make a delivery. They got the side door of the reefer box opened. The driver had a fiber pad on his shoulder, ready to have the helper get a keg onto him. Instead, a full half keg had shifted in transit and was leaning against the side bay door. As the door came open, the keg fell out. The driver saw it and did not want to have to deal with a blown bung. Probably, he would have had to make good for the contents of the keg. The driver got his shoulder into the path of the falling keg. The keg, all 150 lbs of it, came down and smashed the driver's shoulder and collarbone. The helper was standing near the driver and saw the keg hit and bounce off the driver. The helper had the same ideas, wanting to prevent a blown bung. The driver put his foot under the keg as it fell to the sidewalk. The bung did not blow out of that keg. The helper wound up with a busted foot. Both the keg driver and helper wound up in the hospital and the brewery had to send out another crew to finish the route and bring the truck back.
I still have my "cellar jacket"- an insulated denim work jacket worn when working in the refrigerated areas of the brewery, like the lagering cellars. I also have a keg driver's hat- kind of like a policeman's uniform hat with "Rheingold" accross the front of it. The cellar jacket was standard issue to guys in the engineering gangs as well as to the keg drivers. I got hold of a keg driver's hat so I could wander around the loading docks without problems at odd times. It was an easy way to get a half or quarter keg for parties at engineering school. Nowadays, none of us drink as much beer as we used to, so haven't had a keg party in a few years.
Joe Michaels
