While sanding the layers of epoxy while i apply them to the fretboard of the fretless, is it necessary to use a radius block, or will the sanding be light enough for it to not change the radius.
I had good success just doing it by hand and I didn't notice any change to the radius after it was finished.
I always try to use a block. Changing the radius isn't as much of a concern as accidentally sanding out low spots when you sand by hand. That being said, if you're just looking to rough up the surface and then polish, you can probably get away with a bit of steel wool in your hand. If you're looking to do any levelling, use a block. -Nate
Thing to keep in mind when using a block is that is you don't keep the block straight, you will change the radius. I made a guide... looked kind of like a miter box that the neck sat in, and was as wide as the radius block, to keep it straight. I think any flat sanding block should work for what you want.
Instead of being too worried about your radius, I would use a long flat but narrow sanding block sanding parallel to the neck and move it across the fingerboard gradually spending a uniform time on each area. If you try to use a radius sanding block and it is even slightly out from the radius of the finish, you risk rubbing through some of the finish before touching other areas Jeff
didn't the raduis change from applying the epoxy? I used the system 3 mirror coat. It effectivly flattened the radius by getting thicker at the edges of the fingerboard. I am considering next time building up a dam around the fingerboard then filling it in with the epoxy so I have a few mm of epoxy thick even at the center of the board then re-radiusing the board. Any thoughts? ....t