Keg Boiler size 13.5 gallon vs 15.5 gallon?

[J3ff]

I have a couple questions about using a keg as a boiler.

I currently have a 13.5 gallon keg. I know it's an odd size keg, but that's how "Magic Hat" beer is sold in my area. It has a standard sankey flange on top just like a normal 15.5 keg does.

I guess my questions are...

Should I go ahead and and use what I have, or get my hands on a 15.5 gallon? Will the extra 2 gallons in size from a 15.5 make much of a difference? I can obtain a 15.5 for $10, as that is what the deposit on a keg is in my area, and I do own a fridge I converted into a kegerator. That's how I got the 13.5 gallon keg I have now, I just have not been back to get a new keg in a while so it's been sitting empty in the garage.

Also, I have searched a bunch for this and maybe I am not using the right search terms, but how full could I fill the boiler? I have seem some say 1/2 full, others say 2/3rds full, and a post saying they have put 14 gallons in a 15.5 gallon keg. I am not finding any definitive answer.

[Dnderhead]

either keg will work,as for how full it makes a difference what you are distilling as some wash/mash foam so you cant fill as full.

[Coyote]

It will depend on your ferment size along with a 100 other things. Type of heat - Electric vs. Flame ?

I tend to run on the 80% rule and never fill my boiler more than 75 - 80 % full

Bigger is almost always better

and for $10 bucks I'll take 3 or 4 kegs

Good Luck

Coyote

[Boda Getta]

What Coyote said on the 3-4 kegs; in my area deposit on a 15.5 gal Sankey is $50.00

BG

[Bushman]

Keg should work fine, the amount you fill it is relative to the keg size. I am not familiar with that keg is it short and stocky, tall and slender? These questions have something to do with safety as some slender kegs may have a balance problem depending on the type of column you mount on top.

[J3ff]

What Coyote said on the 3-4 kegs; in my area deposit on a 15.5 gal Sankey is $50.00

BG

I am guessing your kegs are much cheaper there. I have read others on this forum talk about how a keg cost 50 with a 50 deposit. The 13.5 gallon keg of magic hat was 110 with a 10 deposit, and a 15.5 of miller lite is 90 with a 10 dollar deposit.....

Here buying a keg only saves you 10-15 over the cost of buying the same amount of beer in cases.

[harmca]

beer kegs can come in
13.21 US gallons = 50 liters or 11.00 Imperial gallons

15.5 US gallons = 58.674 liters or 12.7 Imperial gallons

[freespirited]

I would look into the type of still you are going to do, how long you have to sit a do a run, and what type of heat you are going with. I do 8 gal, takes a long while, I also switched to electric so now to make sure I have the element submerged I add enough water to cover it. Now Im at 11 gallons. Thats more than 75% of the 13.2 gallon keg.