Resin Casting - How large must the compressor be to quickly fill a 10 Liter/2.6 gallon pressure pot at 60 psi?
I have a 2.5 gal pot and use my 21 gal 125 psi compressor. It works with no problem at all. For a smaller and less pricey solution, I would go with at least an 8 gal 125 psi compressor, as it looks like it can provide the pressure for the pot. From the specs I see one like that would give you 5.5 CFM @ 40 PSI. My 2.5 gal pot requires 4.0 CFM @ 40 psi. You'll probably want to run at 30-35 psi, so you'll be good no matter what. 

Depending on where you live, I can say that the 21 gal is worth the money if you're buying from Harbor Freight, as it is only somewhat more than the 8 gal and that 21 gal will keep the thing from running all the time. That's how I ended up with the big one.