Re: Restoring sanded gelcoat
Like bounder says there are different ways to get there. I'll share mine.<br /><br />Before sanding anything I would use a buffer and abrasive compound to see if the finish can be restored. Without seeing it in person its hard for anybody to know whether you need to sand first. <br /><br />In my younger years when in school I used to glass, sand, compound and polish surfboards as a tradesman...normally 10 a day and probably did 3-5000 boards total. Later I worked in the boat mfg industry doing everything from plugs/molds to final product. With that said...Normal procedure in the surfboard industry was to dry sand (triggering 4500 rpms down)with 400 to get the surface level. Then sand (triggering 4500) with 600 grit to get a smoother finish, then compounding (trig 4500)with an abrasive (such as Dupont 202S lacquer compound) and final was to polish (trig 4500)with a non abrasive polish. Old boat gelcoats were done the same...600 grit max, abrasive compound and then polish. Foam pads were used and rpm was limitied to how much experience the user had. Low rpm polishing was only used on boat molds for wax removal. I still go to boat factories and talk to production types, it hasn't changed. And yes, 320 can be compounded down but its faster to sand it down with 400.<br /><br />I'll add a tip here. If painting over gelcoat...Use an abrasive compound to prepare your gelcoat instead of sanding. It is 10x faster.<br /><br />HarborFreight sander/polisher #46507 is a good one for home use. I bought one last year and have some "miles" on it without problems. The only issue is finding accessories that fit.