I'm getting ready to re-gel my Hondo. This will be my first time doing a full re-gel. Does anyone roughly know how many gallons of gel it will take to do an 18ft boat? Single solid color and a coat of clear? I don't want to run out and will buy what I need to not run out, but at the same time gel isn't cheap and I'd rather not have a bunch left over. Also, I'm guessing that I can add a product like duratech to the clear to help with orange peel and add some UV protection? Thanks!