i'm running a 4gauge wire from my battery to a distribution block in the cab of my truckfrom the distribution block i will have a 200w infinity basslink, a 2000w cont/4000w peak inverter and i will have a crane in the bed with a 2000lb winchvery unlikely i will ever have all 3 things going at the same timebut just in case what size fuse should i have on the 4 gauge wire coming off the battery?
sand lightly, clean and prime.
I believe that painting aluminum entails first coat be an acid based primer, and that should be enough of a prep for paintI think I remember that when I worked in a company building painted aluminum AC rooftop units.
As far as the welder goes, if it does run bead, make sure you get penetration and it doesn't just stick.