Question on sanding FB radius

[Steve Sawyer]

On a test piece, I epoxied the MOP inlay into the FB after roughing the radius, then sanded both the inlay and the FB to the final radius.

This seemed to work ok, but I only had two of the 9 inlays to deal with on this test piece. Is it wiser to plane and sand the FB to the correct radius first, then glue in the inlay, sand the inlay flush, then sand everything for the final finish?

Also, how fine a grit should I use to sand the inlay? Seemed to look pretty good at 180 on the test piece, so I'm guessing 220 should be adequate.

Thanks!

[Barry Daniels]

Radiusing the fretboard before or after inlaying is kind of a personal choice. Back when I was doing a semi-production run of archtop necks with block inlays, I inlayed into a flat fretboard and then planed the radius with a router in a radius jig. Then broke out a long sanding radius plane to do the final sanding.

I think 220 grit is WAY too coarse for MOP and especially ebony. You may want to break out an Optivisor and take a close look because I am sure you will see sanding scratches. I take my fretboards up to 600 grit and then even turn the 600 paper over and burnish the fretboard with the paper backing of the sandpaper. This really makes a nice even buffed surface. Try it and see what you think. The only other place that I sand up to 600 grit is acoustic guitar bridges which are also left unfinished.

[Steve Sawyer]

Thanks, Barry. First time working with MOP, and first time working with ebony (at least on a fretboard). My test piece was using hickory as I didn't want to waste an expensive piece of ebony!

[Barry Daniels]

Yeah, hickory would probably look Ok at 220 grit. Ebony is a whole 'nuther ball game.

Question: Are you going to tint your epoxy? I use a little bit of ebony sawdust in my epoxy for inlays.

[John Clifford]

Steve, I assume you are routing the inlay cavities while the FB is flat? If you do that, it really shouldn't make any difference whether you glue in the MOP before or after radiusing, since the same thing happens to it either way. You can definitely see sanding scratches in MOP with anything under 600 grit. However, I personally prefer not to burnish an ebony fretboard. The thing about doing that is it looks great at first, but then everything that touches it leaves visible marks. Depending on the piece of wood, ebony can look really nice at 400 grit - kind of satin as opposed to high gloss.

[David King]

1200 grit for MOP and then a quick buff with 0000 steel wool.

[Steve Sawyer]

Steve, I assume you are routing the inlay cavities while the FB is flat? If you do that, it really shouldn't make any difference whether you glue in the MOP before or after radiusing, since the same thing happens to it either way. You can definitely see sanding scratches in MOP with anything under 600 grit. However, I personally prefer not to burnish an ebony fretboard. The thing about doing that is it looks great at first, but then everything that touches it leaves visible marks. Depending on the piece of wood, ebony can look really nice at 400 grit - kind of satin as opposed to high gloss.

Thanks, John. Yes, inlay cavities were done on a flat FB. However, seems it would be hard to sand the MOP to 600, and the surrounding ebony to 400!

[John Clifford]

With block inlays it's actually not that hard to polish the MOP a little beyond where you sanded the wood. If you go over the line a little, it's not a big deal.

[Steve Sawyer]

Decided to partially radius, then glue in the MOP, then finish up. Brought the fretboard itself to not-quite-done with 80 grit (there are still a few pencil lines down the center), so I'll take it the rest of the way with finer grits to remove those enormous scratches and get it to the final 12" radius.

I don't get to use this plane often. Went on a tear a few years ago and built three wooden planes - a 22" jointer, a jack (pictured here) and a scraper. The scraper didn't work very well as I didn't have the right angle for the iron I used, so it ended up as an ornament on my desk at work until some a-hole stole it <grrrr...>

Anyway, this one is perfect for roughing-in a fretboard. It is padauk and has a lignum vitae sole and a 1/4" thick iron. Like butter - made beautiful little curls of ebony.

If you've never done it, making your own planes is quite easy and very enjoyable, and you get to use the end product. These massive plane irons are amazing, but even a nice thick Hock blade will work well.

With block inlays it's actually not that hard to polish the MOP a little beyond where you sanded the wood. If you go over the line a little, it's not a big deal.

Thanks, John. Good to know.

[Steve Sawyer]

With block inlays it's actually not that hard to polish the MOP a little beyond where you sanded the wood. If you go over the line a little, it's not a big deal.

Thanks, John. Yeah - that wasn't a problem. MOP sands really nicely, so it was easy to get rid of those last scratches.

Only problem (and I knew this was going to happen) it appears that gold MOP is dyed to achieve that color. As a result the dye may not penetrate deep enough to persist once sanded flush. I had a neck that I was using to get some practice with MOP block inlay, and experimented with using a tiny artist's brush to apply some Transtint lemon yellow dye in alcohol. Seems to work ok, and after it dried and I applied some feed-n-wax (what I use to finish my fretboards) the color remained and did not rub off.

The first pic below is the 5th and 7th fret inlays showing how the 5th fret is ok, but the 7th has become "silver" instead of gold. The second pic shows my test neck with block inlays only at the 3rd and 15th fret. They were both somewhat washed out after sanding flush. The pic shows the 15th fret inlay before application of the dye, and the 3rd fret after the dye.

Anyone see any issues with this?

By the way, it seemed easier to rough-sand the FB close to the finished radius, then glue in the block inlays, then sand those flush, then proceed up through the grits until everything is smooth, flush and radiused at 400 grit. YMMV.

[Bryan Bear]

Are you using that plane on the board after the pearl goes in or just roughing in before you inlay?

[Barry Daniels]

It's got to be before inlay. A plane flat will not work on shell.

[Steve Sawyer]

The planing us done on the bare wood, after the inlay cavities have been cut. The MOP goes in after the fretboard is almost fully radiused. In the pic above, the FB has been planed roughly to 12" then rough-sanded with radius sanding blocks, and the inlays glued in.