Yeah I second the no sandblasting. A mate of mine is a panel beater and he told me to steer WELL clear of it. It can be done right but you have to use a particular grit - plastic I think but not many people do it right. There is another method using baking soda and water which I have seen used on 20 thou aircraft flight surfaces- no warping at all. BUT it leaves one hell of a mess and the sludge gets in EVERYWHERE. The last time my old boss used it then he finished painting the aircraft - he parked it out side and when it rained it started fizzing out of all the panel joints!
He never used it again.
Gig
