Reconditioning Old Firestone Soda Kegs (Or: Mike's Not-Quite-So-Excellent Keg Adventure)
Not too long ago, I acquired a couple of really old Firestone ball-lock soda kegs, cheap. When I finally got around to cleaning them up, I discovered that the keg fittings contained some bizarre little plastic spacers, which were quite badly deteriorated. These spacers are essential to proper operation of these kegs, as they help form the seal between the keg fittings and the keg, and also hold the poppet valves in place.
These kegs also use a non-standard gasket on the liquid out dip tube. Instead of an o-ring, the gasket resembles a small rubber sleeve, which fits into a small recess in the top of the keg. (Because of the way these kegs are designed, there is no separate gasket on the gas in side -- the plastic spacer acts as the gasket there.)
I checked several on-line homebrew supply retailers, and posted some queries on the rec.crafts.brewing Usenet group, searching for replacement spacers. A couple of places had spacers which supposedly fit old Firestone kegs, but it turned out they were not the right spacers -- they were too big, and the fittings could not be screwed back onto the kegs with them installed. (I would like to thank Doug Evans of Vinbrew Supply, who sent me the spacers gratis, to see if they would fit -- so this little misadventure didn't actually cost me anything.)
After striking out on getting exact replacement parts, I took a trip to the local Home Depot store, and came up with some suitable alternatives, all from the plumbing section. With about $2.50 in additional parts, and a little tinkering, both of these kegs are now nearly good as new. Here's what you need to fix one of these these kegs up:
If you want to replace the liquid dip tube gasket, you will also need:
Note: If any of the faucet washers have raised lettering molded into the flat side, use some extremely fine wet sandpaper to remove the lettering prior to installation; this will help ensure a good seal. Lay the wet sandpaper on a hard, flat surface, rub the washer against it until the surface of the washer is smooth, then rinse well, to remove the dust.
The first photo shows the original (worn) plastic spacer from the liquid out fitting on the left. On the right is the 3/8L faucet washer, with one of the 000 faucet washers stacked on top of it; this stack of washers will go into the liquid out fitting, replacing the plastic spacer. Even though the pair of faucet washers is slightly taller than the original spacer, the beveled end of the 000 washer will get pushed up into the narrow part of the fitting, where the legs of the poppet are -- so things will still fit together OK. Having the beveled end of the washer jammed up against the legs of the poppet also seems to help the poppet valve seal better, if the poppet happens to be slightly bent or worn...
The next photo shows the 000 washer pushed up into the fitting, against the legs of the poppet.
And finally, the 3/8L washer in the base of the fitting. The fitting is now ready to be reinstalled on the keg.
The procedure for the gas in fitting is identical, except that the 3/8 faucet washer is used instead of the 3/8L, due to the slightly smaller diameter of the base of the fitting. If the gas-in dip tube looks really grungy (the ones on these kegs were made of plastic, and weren't in much better shape than the plastic spacers), just toss it, the keg will still work without it.
Finally, here's my improvised dip tube gasket, shown installed on the liquid out dip tube. I trimmed the washer down with a small pair of scissors and a razor blade until it was approximately the same height as the original gasket (about 1/4"); then I wet sanded the cut edge so that it was smooth and flat. The whole procedure only took a few minutes.
Re-install the liquid out dip tube and fittings, and pressurize the keg. If there are any leaks, continue to tighten the fittings down a little at a time, until the leaks stop. Resist the temptation to seriously over-tighten -- you shouldn't need to crank them down very hard if you've used the proper size washers, and you don't want to risk stripping the threads.
If the quick-disconnects seem to be difficult to get all the way onto the fittings, it may be that the base of the poppets are being pushed a little too far up into the fitting by the small faucet washers, preventing the valve from depressing completely. (This happened to me on one fitting out of four.) If this happens, take the fitting apart again, sand the flat end of the 000 washer down just a tiny bit, and reassemble.
So, was it all worth it? Well, I now have a pair of kegs which I expect will last me many years, at a total cost of around $20 per keg (includes the original cost of the kegs themselves, plus brand new o-rings for the lid and quick-disconnects, plus all those freakin' washers). Yeah, I spent a fair amount of time futzing around to get to this point... but I have an Engineering background, and just couldn't resist the challenge. :-) If I ever encounter this type of keg again, I'll be ready!
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(last updated October 27, 1999)