I’m going to try my hand at doing a resin swirl on a longboard. When finishing my blank, what grit should I stop at? Is 80 enough or should I take it higher, say 120/180? I’m going to do the resin swirl on the bottom and rails with the deck being clear silane. I normally take my sand jobs to 150/180 to be sure the scratches are gone, as I usually do airbrushing. Resin tinting is new to me so I just want to play it safe.
Here we go again on bonding issues and strength, particularly appropriate for longboards, which aren’t generally glassed in proportion to their area (in terms of bending strength). You need to get a good bond, which generally means a slow lam and not-too-finely sanded blank, so the resin can penetrate a little, and saturate the surface fully. Unless, that is, you don’t want/need the board to be durable beyond a couple go-outs.