I want a kettle large enough to boil 13+ gallons of wort. Will a 60qt (15 gallon) kettle provide enough headspace or should I look for something larger?
Also, How many gallons will a keggle hold?
A keggle is 15.5 gallons, and will work OK for boiling 10 gallon batches.
There is a very fine line between "hobby" and "mental illness."
The keggle works fine. You can't let it rip full heat and walk away, but a spray bottle and a reasonable amount of attention will prevent boil overs.
That said, I wish I had the cash to upgrade to 20g stainless kettles. I think they look cooler.
I think its time to look into a keggle.