Hey there! The first thing you want to do is pressure check your tank, then seal and then paint. Don't want to put on a purdy paintjob and then find out that you have to resolder the fuel outlet or something. You should use a hand pump of some sort since you don't need much pressure to check it. Using a high pressure source is asking for shrapnel! Your bike's gonna look sharp with that tank on it. Keep us up to date.