I bought these Sanding Blocks from MicroMark.
They work really nicely with the Rounded side. It makes it ideal for getting into the curvatures of the Bow and Stern areas.
They come with these little Wing Nuts and a Dowel for holding the Sandpaper in.
My only issue is that they are too big for standard Sanding Paper that come in Sheets.
So, to remedy that problem, I bought these Sanding Belts that are made for Belt Sanders and I simply cut them up do they’ll fit.
Otherwise, you’re stuck buying them from MicroMark.
I jus at found out something interesting. When you cut a 3″ x 21″ Bent Sander Paper at the same widths as the Sanding Blocks, there’s one each that’s perfect for each Block. One big and one small. I’m sure they made it like that intentionally.