I have not found anyone in here with this question.This is probably the most important thing in Prepping a motorcycle frame for Polishing.When U folks sand down the frame how do you take out the Black looking this from the crevices of the welds.I know you Polishers know what I’m talking about.When you sand the frame it’s not that bad,then you get to the welds and there deep crevices in the welds,there’s still paint or brush aluminum finish in those crevices and believe me you will not knock it out with a Da sander.I can knock it out but it will make the welds flat,and the welds will get weaker. I s there anyway I can take out the paint or brush aluminum finish in the crevices of the welds. Whats a better way in sand the welds to make it real clean!!