I use Kleen strip - Prep All and I use lint-less rags, before and after sanding. When I wet sand I don't use soap - just water. I don't find its necessary and adding another variable into the mix doesn't sit well with me. A good wax and grease remover is necessary in my book. It will lower your chances of 'fisheyes'. I wear gloves the whole time to minimize the chance of oils contaminating the paint. Filler primers are quite porus and hold onto contaminates really well. I tend to go a little neurotic and get very meticulous with it because if you use high quality paints you can easily be $500 into a paint job in materials alone, you dont want to do it twice. I'm also hesitant about mixing paint brands / lines as I have had cross-link failure between products that were recommended by the paint shop. A great tip I picked up years ago is to take the time to make a tall stand to hold your gas tank, it makes it easier to spray the bottom edges and prevents dust from blowing off the surface below onto your work piece. I know this may seem obvious but I cannot reiterate it enough, read the tech sheets and follow the flash times
exactly.
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