Boiling pot size for single/doube batches ? Aluminum ?

I was wondering around a department store when I happened to find a 68L pot with lid. But its aluminum. The price is right, especially compared to an equivalent SS pot.

I want to brew double batches, 12 gallons racked into the Better Bottle secondary fermentors. With trub and losses and such I figure I need at least 13 gallons into the primary fermentors, plastic buckets. That probably means I need 14+ gallons going into the brew pot at the start of the boil.

Right now I am using a keg cut off below the handles. It holds 14 gallons. Not enough. I have a virgin keg that would give me a 15.5 gallon brewpot, but I figure that is cutting it too close.

So the 68Q aluminum pot would give me 17 gallons.

I also want to brew single batches, using the same kettle if I can. I'd be boiling 7 gallons of wort.

Is 17 gallons too small for a double batch ? Too large for a single batch ?

Does an aluminum pot last as long as a SS pot ?

Does one ever have to worry about overheating an aluminum pot with a big burner ?

Thanks.

are you talking about doing full boils or can you top off later? 15.5 gal won't be big enough for a 14 gal boil. I'm not even sure if you could get that to a boil using normal means.

Maybe check with a restaurant supply store.

I was thinking full boils. Lots of people here brew double batches, right ?