Keg Conversion

Keg conversion is the first step in this whole process. For me it was also an enjoyable, if frustrating, step, because I got to play with all manner of power tools and make noises that made my neighbors wonder about my sanity!

Locating Kegs

This is the most difficult step for some people. I was pretty lucky and was able to find kegs from $5 to $15. One place that I found them was at garage sales. Never underestimate the junk in someone's garage that canbe useful to other people! This was also the cheapest place to find kegs. Bargain, Bargain, Bargain! For those of you that pay close attention to the legal issues, buying a keg from someone at a garage sale is questionable because it is very likely that they just didn't return the keg for the deposit. Nevertheless, I don't feel nearly as guilty as I would if I had received a keg for the deposit and not returned it.

I would also check around at local scrap yards. If you live in or near a big city, there is a very good chance that you may be able to find one there. Check around.

Cutting Out the Tops

I found that there are basically three different ways of accomplishing this task:

  1. Cutting out the top with a plasma cutter
  2. Cutting out the top with a reciprocal saw or jigsaw
  3. Grinding out the top with a grinding wheel

I ruled out option 1 because I simply don't own a plasma cutter, nor do I possess the skills to use one. Tom and Mike Ramsey from my homebrew club, NTHBA (North Texas Homebrewers Association), use this method to cut out tops of kegs. Tom says that it eaves a perfectly circular opening that has smooth edges. For anyone interested, I think that they charge $15 to cut the top out.

I tried option 2 first. Unfortunately I don't own a reciprocal saw, but I do own a jigsaw. First, I tried 22 TPI (Teeth Per Inch) blades, which melted down very quickly. I then tried 14 TPI blades, and ended up going through about six of them. The hardest part was trying to cut in a circle with the jigsaw. The jigsaw's body got in the way of making smooth circular cuts. I ended up drilling six holes in a hexagon pattern on top of the keg and then playing connect the dots. You also need to make sure that you don't stop during cutting, otherwise when you try to start again, you are likely to break your blades if you are not careful. For me, this was too much work for the result, which was very ugly and sloppy. I have little doubt that a reciprocal saw would work much better, but I think option three definitely has it beat!

I read that some people had used a grinding wheel to cut off the tops of their kegs, but I was reluctant to try this approach, because I thought
it wouldn't be safe. Well, my friend, Jeffrey Boyd Mitchell, was down for the weekend and we were wandering around the local Home Depot to pick up some extra jigsaw blades, when Jeff saw a grinding wheel for a circular saw and said, "Why don't you try this?" I voiced my reluctance, but he called me a few diminutive names and convinced me to try it. It is a 6 1/2" fiber reinforced grinding wheel called a "Fastcut Metal Cutting Blade", made by Norton Company, Consumer Products, Worcester, MA 01606. The part number is 89098. The UPC label is 0 76607 89098 6. FYI, it cost about $2.50.

After putting the blade in my circular saw, I figured out that my circular saw wouldn't fit on the top of the keg, because my circular saw has a very large flat guide to aid in cutting flat surfaces. Luckily, it only had four screws holding it on and was very easy to remove. The usual disclaimer applies: it is not recommended that you alter your power tools!

Here is how I would proceed next, now that I have a little experience with this:

  1. Trace a circle on top of the keg for the size of the opening you desire.
  2. Before proceeding, wear hearing and eye protection! I also recommend wearing long pants, because hot metal shards will go flying all
    over the place!
  3. Make sure the keg is partly filled with some water or stale beer before you begin. This add to stability while cutting.
  4. Make sure you depressurize the keg.
  5. I began by working slowly to get a feel how the blade cuts. I did not plunge the blade all the way through right away, but rather ground a small section evenly and worked my way through the keg wall. Work your way all around until you are done!

I have done about a half a dozen kegs this way. Now that I have some experience with it, I can easily cut the top out in about five minutes. This is much less time than it took with the jigsaw, plus, I am still using the same blade which cost only $2.50. The cost savings are incredible!

23 March, 1998 -Red Wheeler reports that an angle grinder will provide the same function as the circular saw.

3 August, 2003 - Eric Zamonski recommeds using self-tapping sheet metal screws to create the starter hole to accept the jigsaw blade. After removing the screw, then widen the hole with a drill bit. No more spending a lot of money for drill bits!

Cleaning up the openings

After I was done cutting the tops out of the keg, the openingswere pretty rough. To clean them up, I used a silicon oxide grinding wheel that attaches to my drill that I bought at ACE Hardware for about $1.50. The first grinding wheel that I bought at Home Depot, a Vermont American model
16710, is small in diameter, and doesn't work nearly as well as the one that I bought at ACE which is a large diameter. Work your way around the edge and smooth out anyburs. I spent about ten to fifteen minutes per keg. Jeff helped me on some of my first kegs. Thanks Jeff!

I have also heard that some people have used belt sanders to smooth out the rough edges. I have yet to try it, but it sounds
like a great idea! The problem is that my belt sand is an old industrial model and weighs about 45 pounds! If anyone wants to volunteer trying this thing on one of my kegs, let me know!

Bulkhead Fittings, Soldering, and Welding

The biggest decision in converting kegs is how to attach your plumbing.There are a plethora of ways:

  • Bulkhead Fittings: There are a number of commercially available bulkhead fittings on the market. You can see a picture of some in use at Rick Calley's page. The downside to the commercially available fittings is that they are pretty
    expensive. As a result, many people, including C.D. Pritchard and Al Korzonas have come up with their own bulkhead fittings that are much more cost
  • Soldered Fittings: Stainless steel can be soldered using silver bearing solder and flux. From experience and hearsay, I understand that it is a difficult material to solder. It is much different than soldering copper, IMHO. People that have used this method include Rick Calley and Scott Dornseif. Scott has given me wonderful instructions on this method.
  • Welded Fittings: There are two types of welding that are available for stainless steel, TIG (Tungsten Inert Gas) and MIG (Metal
    Inert Gas). TIG is the preferred choice, but can be quite expensive. If you can find it for a reasonable price, definitely go with it. MIG is a less preferred
    choice, because there is more damage to the SS than with TIG. Most people either have 1/2" SS (Stainless Steel) pipe nipples or couplings welded to their kegs. The couplings are preferred by some people, because it gives them a flush surface to work from on the inside of their keg, thus giving more flexibility. For a good source of SS fittings on the web, try

My Experience:

First, I want to thank all of the members of the Hombrew Digest (HBD) for all of the responses that I received on keg conversion. There are literally too many people to list, and if your name is not mentioned, know that I am thankful for your help. On the recommendation of Scott Rogerson, I first attempted to follow the design of Rick Calley who uses a 1/2" female NPT to female garden hose adapter screwed to a 1/2" NPT to male garden hose adapter. He first drills a 3/4" hole in the keg wall. Then he screws the garden hose fittings into each other through the keg wall and then solders them in place (illustration)I have the following problems with this method:

  • Drilling a hole in the keg wall was difficult, to say the least. I bought a bimetal hole saw and tried to drill through the side. I went too fast
    and ended up melting the teeth. That was $10 down the drain. To finish the hole, I used jigsaw to cut out the hole, and then used my small diameter grinding wheel to finish it. This was a RPITA (Royal Pain in the Ass!)
  • After I tightened down the fittings, I soldered them in place. I really should have practiced beforehand, because the solder did not flow like it
    should. I have since been told that it was probably because 1) the stainless steel oxidized because I overheated it, or 2) I did not use enough or the right type of flux. When I heated water in this keg, the seal dripped a little. Afterwards, I did receive excellent href="brewing.php?page=soldering">instructions on how to solder SS from Scott Dornseif .
  • The price of the two fittings together was more than a 1/2" SS coupling.

I then toyed with the idea of using a bulkhead fitting. Commercial units were way too expensive, and I decided not to go make my own because the parts were more expensive than a SS coupling and almost as expensive as having a coupling welding to my keg. I would also have to drill more holesin the kegs, which is something that I wanted to avoid.

As a result of the above difficulties, and with the recommendation of Dion Hollenbeck , I decided that welding was the way to go. Tom and Mike Ramsey from my homebrew club, NTHBA (North Texas Homebrewers Association), cut holes and weld fittings for $10 plus
the price of the fittings. This was too good for me to pass up. Unfortunately, they use the MIG method of welding. Compared to the TIG welds that I have seen, there is a lot more corrosion. There was also a little misunderstanding between Tom and myself about how I wanted the couplings welded. Instead of welding the couplings so that there is a flush surface on the inside, the couplings were actually welded so that there is an equal amount of fitting on each side of the keg wall. This is really inconsequential, because the fitting only protrudes about 1/2" into the keg. In spite of these two problems,I am very happy with the welding job. If I notice any serious problems due to the MIG welds, I will be sure to relate them here at a future date.

Insulating the Kegs

The first time that I mashed in a converted keg, I found that the temperature drop was unacceptable. In my research on the Internet, I found href="brewery.php?page=keginsulation">Mike Spinelli's Solution from HBD 2407 to be the best idea that I have ran across. He uses 16" OD stove pipe and 2" rigid fiberglass insulation to make a removable sleve that can withstand a great deal of heat. The only disadvantage is that it costs around $50 dollars to insulate one keg.

Front View of Keg Insulation

My solution was a little less expensive. Using materials that I had on hand or could aquire very inexpensively, I built a "Barrel" out of wood, aluminum flashing, galvanized steel flashing,staples, and liberal numbers of screws. It was a long and involved building process, but I am a sucker for a good project, so I gave it a whirl.

The first step was to cut slats from 2"x8" stock that were 3/8" thick and about 21" long. This would be impossible without the aid of a table saw. The next step entailed placing a number of slats, the length of which would equal the exterior diameter of a keg, on two very long pipe clamps. I then tightened the pipe claps so that the slats became compressed. I then stapled two long and narrow pieces of aluminum flashing to the slats. I
originally was going to use galvanized flashing for this, but my staple gun would not puncture the flashing. I even went out and bought an electric heavy duty staple gun to no success. Upon releasing the clamps, the slats bowed in towards the direction of the flashing. I then wrapped the curving slats into a cylinder and stapled the leftover flashing to the other end.

I then repeated the process again to create a cylinder that was approximately 4" larger in diameter. I then used small wood blocks as spacers and screwed the two cylinders together.The inside was filled with fiberglass house insulation. To protect the ends, I used galvanizedflashing. Since my staplegun wouldn't puncture the flashing, I used screws to secure it in place.I first attached it to the outer cylinder, and then cut many slits in the flashing so that I could wrap it over to the inner cylinder.

This system has worked very well, but it was a major time commitment. Also, flashing of any sort tends to be very sharp. I got several good nicks. After my friend, superb brewer, and fellow poker player, Dave Draper saw this insulation, he came up with a much more practical solution. He simply sandwhiched house nsulation between two layers of fiberglass window screen and wrapped it around his keg, securing it with bungee cords. And they say academics
have their heads in the clouds! :) I think that I am going to use a similar solution for my remaining two kegs.

Note: I haven't insulated the brewkettle or the HLT, as I have found it to be unnecessary.