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For my current project, I wanted to try a compound radius. I thought long and hard about how I wanted to tackle this, then threw it all out the window and did it my hand. I carpet taped the slotted and tapered board to a marble slab and used a plane. I followed the taper and tried to take full strokes along the string paths. I was surprised how QUICK AND EASY it was. I didn't bother to measure the radii but they feel about right and a straight edge shows the board is straight along each string path. The board is fretted and attached to the neck (90% carved) but I am not near ready to put the whole guitar together, so I may run into unforeseen setup problems, But I don't think so.

Well, I did the first 8 guitars with a sanding block. It sucks!!!! 60 grit to hog, 80/100 grit to remove 60 grit sanding marks, 150,180,220,320. The first few grits are going to need a fair amount of human power sanding back and forth, back and forth.....with the remaining needing about 30-40% as much sanding. So after the initial hogging off of material (and during) one needs to stop, brush off the sandpaper of dust, vacuum up the dust off the board and continue, then after one grit is done, you need to load the sanding block with fresh paper of the next higher grit. If stick on sandpaper is used, this is pretty quick but still needs to remove the first grit, clean off the block of any possible glue residue and stick on the next grit etc... everything takes time.

The other factor with sanding in the radius is that it's easy to get the board thinner on one side versus the other (bass to treble side) so a decent sanding jig needs to be made to ensure the sanding block is held parallel to the surface holding the fretboard.

With my jig, I only need to set my router hight which takes about 1 minute (or less) then I'm routing. I can go right to 220 grit backed by my hand after routing... Once my board is thicknessed, tapered, slotted and bound, it only takes me about 3-5 mins to get the jig down, tape the board in place (vacuum would be quicker), set the router bit height and route (4-5 passes is all it takes). So for me at least, this is much easier and quicker and I like it

The other factor with sanding in the radius is that it's easy to get the board thinner on one side versus the other (bass to treble side) so a decent sanding jig needs to be made to ensure the sanding block is held parallel to the surface holding the fretboard.

If all you are doing is trying to sand off the tool marks using 320 grit paper, wouldn't a soft foam/sponge type sanding block be all you need?

Here's Virgil's rig - viewtopic.php?f=10123&t=33929

This one makes it a snap to do compound radii-- simply put the appropriate radius forms on either end, and bob's your uncle [:Y:]

I plan to build one similar this weekend. As a matter of fact, this weekend will consist of plenty of jig-making and tool tune-up activities.

I never knew radiasing a board could be so complicated

I sand a short section on the nut end with a 16" radius block, sand a short section on the bridge end with a 20" block and then connect the two sections with whatever plane is sharpest at the time.

works fine with slotted or unsloted baords
easy to make a whatever compound radius you want
only needs short radius blocks
gets a nice surface with a minimum of sanding

-jd

Roger, this type of jig will only do a cylindrical radius, not a compound.

Roger, this type of jig will only do a cylindrical radius, not a compound.