It isn't that hard to get your hands on a used keg. They can be found in almost any city that sells beer. There are aftermarket parts and adapters specifically for the purpose of converting a keg into a still. And, the keg still is the tank of the home distilling world. It's dependable and durable.
When deciding to build your own whiskey still there a lot of choices out there about designs. One of the best choices for the first time still builder is the converted beer keg still.
This post is a written account of a keg conversion done by Tom Kat from the Moonshine For Beginners group at MeWe.com
Step-By-Step How to build a keg still
Step 1: Remove the tap valve
In order to attach a column to the top of the still you will need to remove the tap valve. This can be done by removing the retention ring that holds the valve in place, then turning the valve until the retaining tabs line up with the slots of the valve flange. I've included a good video that visually explains this process.
Safety Note: DO NOT forget to depressurize the keg before trying to remove the valve.
Set this valve and spear to the side for now. You will be using part of this assembly later to make a drain valve in the bottom of the keg. Now you can wash and rinse the inside of the keg.
Step 2: Install ferrule for electric heating element
This step is only necessary if you are planning to heat your still with an electric element. You can also choose to install the ferrule even if you are planning to use another heat source, but want to still have the option later to use an electric element.
If you want to install a ferrule for an electric heating element you need to choose which size to go with.
Drilling the hole for the ferrule
Once you've decided which size ferrule you want to use you need to get the appropriate size drill bit to drill a hole in the side of the keg as close the bottom of the keg as you can.
Use a 1 3/8" bit for a 1 1/2" ferrule or use a 1 7/8" bit for a 2" ferrule.
You're drilling stainless steel so the bit you use can't be just any ole bit. I recommend the Klein Carbide Tipped Hole Cutter. Click the image below to check current pricing on Amazon.
When drilling a hole on a curved metal surface, like a keg, it is critical that you punch a dimple in the metal at the center of where you want the hole to be. If you don't, the drill bit will want to "walk" all over the place instead of drilling where you want it to.
This can be done with a specific tool called a center punch or can also use a 12 d nail.
Now you can drill your pilot hole with a 1/8" bit, then use the Carbide hole cutter to drill out the hole.
Welding the ferrule over the hole
Finding the stainless steel tri-clamp ferrule locally will be a tough task for most people, but luckily these items are easily found online. Here's a link to Ferrules you can get at Amazon.
Welding stainless steel is a special skill. It's a good idea to farm this work out to a professional fabricator. Just about any fabrication/machine shop is going to have a skilled professional to do this work. It's just up to you negotiate the price/trade.
Now the ferrule is installed and swapping out elements will be a breeze. It's time to move on to the bottom drain.
Installing a drain valve
A drain valve is very handy to have. This will allow you to drain your backwash from the still without having to try to lift or tip it while it's full of liquid.
The pic below shows the drain valve extending from the bottom of the keg. Included is the valve and a garden hose adapter for attaching a standard 5/8" garden hose.
Cutting the hole
For this hole you want to use a 3/4" inch hole bit. Again, you want to make sure you're using a bit that will be able to cut through stainless steel. Follow the same steps as before to make the hole in the center of the bottom of the keg.
The drain assembly
To build the assembly you'll use the spear from the tap valve you removed at the beginning. The spear is the stainless steel tube. You need to cut it to length so that it extends from the center of the keg where you drill the 3/4" hole to the edge of the keg.
Now you need to weld, or have welded a 3/4" stainless steel elbow on one end and a stainless steel coupling.
Stainless steel fittings can also be hard to find locally. Here are some more links to these parts on Amazon.
Now have the elbow section of the drain assembly welded to 3/4" opening.
It's also good to have some feet welded to the bottom of the keg in order to hold it off the ground enough for the drain to clear the ground.
Now it's just a matter of threading a 3/4" ball valve into the Stainless steel coupling. These are commonly found any any big box hardware store and adding a garden hose adapter, also found at your local hardware store.
Installing the column
You're almost done. All that has to be done now is installing a column.
2" tri-clamp columns can be purchased pre-manufactured. This article doesn't go into how to make your own column, but there are many variations of these manufactured columns available in lots of places online. Below is a link for the column used in this build.