Quick & Easy Corny Keg Modification.

When I first began kegging, I knew nothing about the process let alone the kegs themselves.

By far the most common system used by home brewers for draft beer is the 5-gallon soda canister, originally manufactured by the IMI Cornelius Company (Annoka, Minnesota). Though other companies also make similar models, notably the Firestone brand (Spartanburg Steel Products, Spartanburg, South Carolina), whose kegs are virtually identical to Cornelius's, although all parts are not necessarily interchangeable. The style is usually referred to as a Cornelius or "Corny" keg. These stainless steel canisters were developed and used to distribute premixed soda for common restaurant dispensers. The keg shape, capacity, and fittings are standardized, and over the years millions have been manufactured.

Kegs are available with two types of valves, ball-lock and pin-lock, which refer to the method used to couple the hose fittings to the valves. The fittings are threaded slightly differently and are not interchangeable, so it's a good idea to pick one keg type and stick with it to avoid confusion. Ball-locks are a bit easier to disassemble with your average socket set.

For what it's worth, Pepsi exclusively used ball-locks, and Coca-Cola used pin-locks. Ball-locks are a bit more narrow, Pin-locks are a bit wider, and the pin-lock valves, when attached, are taller.

Enough about all that.

When I received my kegging equipment I became the proud owner of two Firestone Challenger VI kegs. When I disassembled the kegs for cleaning I noticed that the gas-in dip-tubes were these little red plastic things. I was under the impression that all of the dip-tubes in these kegs were stainless steel. A little research revealed that some of the later model Firestone Challenger kegs used these plastic style dip-tubes. For what it's worth Cornelius brand kegs have all stainless dip-tubes as original equipment.

A closer inspection of the plastic dip-tubes revealed that they were in less than optimum shape. They were both warped around the flared end, one much worse than the other.

During reassembly of my kegs after their initial cleaning, one of the plastic dip-tubes split around the flared end and broke. Actually, it became jammed up in the post and poppet valve, it had split when I tightened the post down. The first thing that came to mind was I'll need to replace the dip-tube. Well it was much harder to source the plastic dip-tubes than I thought, the one company I found that sells them wanted $2.00 a piece and had a minimum order amount of $10 (Chi Company). My second thought was I'll just buy some stainless steel dip-tubes, this way I wouldn't need to deal with the plastic dip-tubes breaking. I bought two stainless dip-tubes for $0.99 and found that they didn't fit! The stainless tubes are wider in diameter, and the gas in post is reduced (wider at the top, then narrows half way in).

Regardless, this is what led me to modify my kegs to use the stainless dip-tubes, and that's what this post is all about.

Here are my original guts:

Here is a picture of the original plastic gas-in dip-tube.

The flare on this dip tube was not as badly warped as the first. I needed to modify the first keg right away, and I wanted to make sure this modification would work. I forgot to snap a photo of the other plastic tube, but it was in bad shape.

This is the OE dip-tube, the replacement Stainless Steel dip-tube, o-ring, and the 5/16" carbide drill bit needed to drill out the post. 

The plastic dip-tube fits right in:

The stainless dip-tube does not fit:

Hence the need for the drill bit...

...and the drill.

(I stuffed some paper towels in the keg to catch the oil and some of the metal flash.)

(Make sure to use some lubricant. I prefer vegetable oil over cutting oil, it is easier to clean up).

Almost finished...

I didn't have a round file or better tool to deburr the edges, so I reamed the post out with the drill bit.

A quick clean up and check for fit:

Add the o-ring and it's complete!

This was a very simple modification. It takes about 5 minutes.

Some things to remember:

1. 
   
   Use a carbide drill bit (it will make your life much easier when drilling stainless steel.)
2. 
   
   Use some lubricant (vegetable oil, cutting oil, etc...)
3. 
   
   When drilling - go slow, and use an even steady pressure.
4. 
   
   If you have a round file, or a deburring tool use it, it will make the SS tube slide right in.
5. 
   
   Enjoy that you will never have to dick-around with those plastic pieces of junk!