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This weekend I put new frets on a persimmon FB for an acoustic nylon/folk gtr, that I am building.Usually I fret with the fb glued to the neck, and then I do all my fret prep work . This time I decided to do it differently, by using my arbor press with stew- mac caul, instead of pounding the frets into fb after it was glued to the neck. Noticed that there was a slight wedging action by using the arbor, each end of the FB was abt 5-10 thou higher at the ends than the middle . When using a straightedge on the bottom of the FB. I have only knocked the edges off of the frets to eliminate the burrs, an polished the long edges. I/m guessing that by epoxiing the fb on my cherry neck, that I can flatten the frets , and then proceed with rounding the fret tops using a fret file , and polishing . Your thoughts or methods please ??Thanks

If I am reading that correctly, your fretboard is bowed up at each end? Normally when I fret off the neck the middle of the FB is raised off the bench when I am done. Either way, if your neck is straight and flat, you should have no trouble gluing the FB to the neck blank using a good sturdy caul and leaving it clamped overnight. Once you remove the clamps, everything should be right as rain.

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PMoMC

Yeah that's odd, usually your FB will be high (bowed) in the middle and not the ends. But it doesn't sound like much. Just use a nice flat clamping caul radiused to your fret board and notched out where the frets lay. FWIW this is why I always fret after the neck is set. I've done it a few times this way and while it's a lot easier to fret it's a bit awkward gluing it down.

I think his board is bowed the direction you would expect, but he is measuring from the back side. After I fret a board, I raise the ends up off the bench with 1/4 inch shims and clamp the center down overnight. Then it is pretty flat and glueing to a carved neck is no problem. Grumpy taught me that trick.

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Bryan Bear PMoMC

Take care of your feet, and your feet will take care of you.

your right brian , I measured looking from the back.I made a sturdy red oak caul with cutouts for frets , an will epoxy and leave on caul for 24 hrs to flatten.I can see some advantages to fretting using the arbor, but will probably glue on fb in future right after fretting with the arbor press, It looks like it creates a wedging action rt in the middle of the fb as both of you mentioned, making the bottom come up abt 5-10 thou at each end,

Although I'm a maker of fretboards, I'm not much of a guitar maker but here's some tips I picked up over the years from reading and discussions with David Collins, a long time guitar repair guru.

Basically in his opinion, the typical fretboard slotted at .023 is a little tight and although it holds frets very well, it does create a bow in the board when fretted. His suggestion is to slot closer to .025 and use either CA or HHG to help lubricate the frets on the way in and hold the frets when they're in. He feels that un-glued frets will eventually work free well before a glued fret (and Dave, if you're reading please chime in if I mis-stated something).

As to boards that are already bowed from this exact mechanism, Grumpy passed along these two tidbits:

1) when pressing in the frets, hold the caul in the pressed position for several seconds once it's seated (Edit: several minutes is better, see post below). If I recall correctly, he has a jig that uses toggle clamps to press the frets. He presses one fret down and toggles the clamp to hold it down. He then moves to the next fret and does the same. When he's done with the second, he moves the first clamp to the subsequent fret and repeats this process until the board is fully fretted.

2) If the board does have some bow to it, he'll raise the nut and end part off the bench and put a weight or clamp in the center and let it sit overnight. By morning the board is usually flat.

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I copied Mario's jig and use it all the time-

I press in with HHG and leave pressed (at lots of pressure) for 1/2 hour or so. After doing all the frets this way the board stays perfectly flat after. When I just pressed and held for a few seconds I did get a bow. I deal with squeeze out at the very end and it pops off easily with a chisel as the squeeze out was never clamped.

Doing it this way lets me work on other stuff while also installing frets. I am looking around for a photo but can't find one at the moment, I am sure there is one in the big docu-build I did in the tutorials section.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

It creates the same stress whether you fret it on the neck or off. Although either way can work, one advantage of fretting off the neck is that you can take the stress out before gluing the board to the neck.

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Thanks guys, I just finished epoxying the fb,If anyone has a copy of that jig I/d like to make one , so basically each fret is clamped in individually with hhg, an clamped for 1/2 hr.Have used elmers glue in the past to seat frets.This time by using the arbor press and a 1 lb harbour freight plastic hammer , used a combination of arbor press, hammer , and clamping with a fret caul to get the job done .Will check tomorrow to see if the FB has flattened out.