Went with: 220, 320, 400, 600. Polished with Surf Polish and McGuires. Original 220 scratches still show thru. I sanded each level complete but I guess I didn’t. Machined all the way. Wet sanded with the 320 on. Any ideas?
It’s hard to see where you’ve hand sanded in the finer grits. Even harder when wet sanding. If you don’t want to live with it as-is, resand it again dry with the sander. I recommend that you make a soft foam disk (at least 2" thick) to fit on a spare sanding pad. The thickness will allow you to powersand the rails without digging in. Take off the gloss with 180, then go 220, 320, 400, 600 dry. Blow off the paper periodically to reduce loading. Cut your gloss with 10% styrene and recoat. Sand the tape lines, and start with 400 lightly, then 600. You can do this wet, because any 400 areas you missed will still buff out.
220, On the gloss coat I wet sand exclusively, and have had good results. The trick to catching those pesky scratches is to rinse the board with water after each grit and wipe it down with a clean towel or paper towels. Before it’s completely dry, and still has a wet shine on it, look at the surface at an angle with good light. You’ll see any scratches, and you can correct them. If done right, you’ll get all the 220 scratches with the 320, all the 320 with the 400, etc. You shouldn’t have to hit any area more than 4 passes with each grit.
A great sanding pad for wet sanding is a wood block with 1/8" cork glued to one side. My block is big enough for a half sheet of sandpaper, and is made from 1/2" by 7/8" mahogony strips epoxied together.
Also, buy high quality wet sanding paper. It’s expensive, but makes a huge difference in the speed and eveness of sanding. Automotive paint supply shops usually have the good stuff. Doug
Howzit 220, First, why did you start with 220, I start with 320 and that’s only on the bottom to make sure there’s no ridges. A good trick is to turn up the RPM’s on the polisher on the last few passes of each sanding phase of the rub out.Aloha, Kokua