Keg coversion questions

[Jared311]

So I started converting my 15.5 gallon stainless steel kegs into an HLT and MLT. I used a 4-1/2" angle grinder to cut away the tops as shown in the picture below. However, I can't seem to make the cuts as smooth as I had hoped. If you have converted a keg, I was wondering what you did to make it a little safer. I was thinking about putting something around the rim that could handle high temperatures.

Also, next I am going to be drilling all the holes for the 1/2" NPT couplings. What was your method for drilling the holes? I was thinking about purchasing a bi-metal hole saw or drill bit.

EDIT: Never mind about the pic

 

[FlyingHorse]

https://www.homebrewtalk.com/wiki/index.php/Keggle#Converting_the_keg

 

[The Pol]

cutting the tops sucks, make sure your grinding wheel is not too thick... takes longer. ALSO, use a step drill for your holes... not a hole saw or regular drill bit... on stainless you may never get through.

 

[Denny's Evil Concoctions]

Lower speed on the bits. I used a hole saw for the first keg. It worked but you basically kill the holesaw. SS hardens when it gets hot so go slow and oil often.

I bought a step bit for the other 2 kegs. They work great.

 

[Jared311]

Anything specific such as bimetal, cobalt, or nitrium coated?

 

[MashStirBrew]

Anything specific such as bimetal, cobalt, or nitrium coated?

Nope, just make sure you use oil and low speed. Try harbor freight or other discount tool stores for a step drill. They can be pricey.

 

[limey lou]

that jig in pic is nice looking but i just used 2 X 4 block like this:

..and it cut a beautiful hole!

 

[EvilTOJ]

Dude just do it by hand. What's the worst that could happen?

 

[The Pol]

Dude just do it by hand. What's the worst that could happen?

Actually I did mine by hand and it turned out great.

 

[menschmaschine]

So I started converting my 15.5 gallon stainless steel kegs into an HLT and MLT. I used a 4-1/2" angle grinder to cut away the tops as shown in the picture below. However, I can't seem to make the cuts as smooth as I had hoped. If you have converted a keg, I was wondering what you did to make it a little safer. I was thinking about putting something around the rim that could handle high temperatures.

Also, next I am going to be drilling all the holes for the 1/2" NPT couplings. What was your method for drilling the holes? I was thinking about purchasing a bi-metal hole saw or drill bit.

For the top holes, I did the finishing touches with a series of files and sandpaper. It really didn't take that long and now they're smooth and won't cut me! For the ball valve holes, I'd recommend getting a decent step drill bit and cutting oil. Stainless steel can be a beeyatch to drill through... especially with a cheap hole saw. I had 6 holes to cut (3 kegs, ballvalves and thermowells) and the step drill bit with cutting oil peeled the stainless steel away like it was wood.

 

[Jared311]

I did mine by hand and was able to make a very nice clean circle cut. I think I just need to put some elbow grease into it and just use some fine grit sand paper. I still think it would look really nice to apply some sort of plastic covering around the rim. It would make it look like a perfect circle and ensure no injuries. I will let you know if I find anything of value.

As for drilling the holes, I did purchase a step drill bit from harbor freight the other day, but it seems as though I might want to start a small pilot hole first.

Thanks for all the advice so far.

 

[Bobby_M]

I cleaned up all my cuts with the same cutting disc on the grinder that I used for the cut. It makes quick work of the folded over edge that forms on the underside of the hole. Once there are no more knife edges, I went to sandpaper. A flapper wheel would be nice too.

While people do love step bits, the thing I don't like about them is that you're basically drilling the hole many times, once for each time you reach the next step. If you already have a bi metal holesaw kit, go to one size smaller than you need and clean it up with the step bit to the actual size. I cut exactly 8 holes using a bimetal hole saw and it's still cutting like new. Slow speed, high pressure, cutting oil.

 

[CodeRage]

I hand cut mine with an angle grinder and cut off wheel. Traced it out and and made about 5 light passes.

As for knocking out the holes, I used a unibit step bit. You definitly want to drill a small pilot hole and go slow with the unibit with a ton of pressure. I tried to use one of my hole saws but the damn thing walked around on me marring the surface a bit. I ended up finishing it with a unibit.

I was tempted to use a metal die knockout but was afraid it may demple or flatten out the remaining keg wall.
Something like this
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=91201
Would be much faster than any hole saw or step bit

 

[Jared311]

I am thinking of borrowing a hole punch from work. Anyone have any success with those?

 

[WBC]

Post #7 grinder fixture works well to make a nice round 12 inch hole if you set the radius 1/16 larger than the cover you will be using (ie: 12 inch). I used a 2 inch round delrin material with a counterbore to fit the sanky spear flange which I attached to my wood as shown (post #7) which fits the Sanke keg exactly. I have cut 4 kegs now and you just have to replace the cutoff wheel when it gets too small to cut correctly.

 

[Denny's Evil Concoctions]

I am thinking of borrowing a hole punch from work. Anyone have any success with those?

Yes. I used one for a few fitting a added later. They work great.

 

[Jared311]

Excellent! That would make life a whole lot easier.

 

[98EXL]

I like that jig idea with the angle grinder....seems idiotproof!

 

[conpewter]

The jig works great.

Plus angle grinder and clamps
=

Also I just use these step bits for my Keg conversion and kegorator needs:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96275

use some cutting oil (though in a pinch PAM can work I hear), I did not drill a pilot hole, just used a nail set to put a small dimple in the keg where I wanted my hole to be so the step bit wouldn't wander.


I go around the edge of the top hole with some sandpaper to knock off the burr after cutting, same with the smaller hole after the step bit (to 7/8")

 

[Jared311]

Also I just use these step bits for my Keg conversion and kegorator needs:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=96275

Yeah, I picked up the same set of step bits this weekend from Harbor Freight. They drilled through the stainless steel pretty smoothly. I just made sure to constantly oil it up and go slowly.

 

[Jared311]

Update:

So I tried several different methods to drill the 1" holes for my couplings. I found the best method is using a 1" bimetal holesaw that I picked up from Lowes for $10. The trick is to first drill a hole in a long piece of wood and then clamp that down to the keg on both ends. Now the holesaw can't jump around and eat up the edges. I used oil and went at it slow and was able to drill 9 holes in less then 30 minutes. Then I cleaned up the edges and the surrounding area with sandpaper. Next weekend I am having a guy from work weld them all on for me. The best part is that it will only cost me $35 for filling up the tank of Argon. Of course I am going to bring his a case of beer to thank him for his handy work.