I just refretted an old acoustic. I expected it to cause some back bow but not as much as I'm seeing. Looks something like 1/32 to 1/16 or more like .020-.050 gap on either side of the middle hump. That seems like a lot for string tension to overcome. The neck had a very slight back bow before fretting which I left thinking it would make it somewhat easier to get the frets in. Any advice??
Refretting
- Thread starter zepfan59
- Start date
keith.rogers
Well-known member
You need to have the neck straight before you refret, unless you are putting in tight frets to try and fix a neck that has too much relief.
Non-adjustable truss rod?
Pull the frets, and see if it will pull into correct relief without the frets when tuned. If it does, you need that to be the state when frets are put in, i.e., get a fret slot saw that fits the frets you are installing. Or, correct the backbow without the frets, so putting them in does not cause a backbow that the string tension can't overcome.
Non-adjustable truss rod?
Pull the frets, and see if it will pull into correct relief without the frets when tuned. If it does, you need that to be the state when frets are put in, i.e., get a fret slot saw that fits the frets you are installing. Or, correct the backbow without the frets, so putting them in does not cause a backbow that the string tension can't overcome.
Thanks Keith. Adjustable truss rod. To begin, this is a Sigma, Martin spec D28. I was given this guitar already stripped of hardware. It was damaged with body cracks that I fixed. However the previous owner said he had the fret board sanded and it was pretty darn straight. I had it for over a year while I worked on the body. When I started on the frets there was still some glue and trash that I filed out. Once clean I measured the slots at .020-.025 wide. I also filed a slight edge bevel on each slot. By the time I got around to fretting I notice a slight back bow, very slight. I bought the Stew-Mac, medium (#152) that was supposed to be like martin, for .023 slots, but with the taller fret crown. MANY people said they made this change successfully. I've done fret work before, levelling, crowning, but never installed or pulled. I'm real leery about pulling them - Or more honestly, scared shitless. There was already some fretboard scars from the previous pull.
keith.rogers
Well-known member
I'd put a nut on and get it up to tension, let it sit for a couple days and see where you are at. You might have to pull some frets to determine if it's a fret slot width problem or the neck needs some other kind of work.
Those #152 frets are probably similar (tang width) to the Jescar 43080, which is a bit narrower but more standard Martin fret size - what I've used the last few times I've done frets, so probably not the wire, per se, that's the problem. A good fret saw is an investment, but if the wire is the right size, I've gotten away with just cleaning the existing slots out well.
Keep track of the chips and stick them back with a dab of superglue, and save the sawdust (or make some more from scraps) if you need to do any more filling.
Steenamaroo
...
I'm no expert on the topic, far from it, but I did refret an old Yamaha last year.
It didn't matter much if I made a mess of it so it was a good learning experience but, as it happens, it went really well!
For removal I adjusted the truss so the neck was pulling back, effectively opening the slots a bit.
I went over each fret with an iron and lifted them one by one with a razor blade, going in flat then levering slightly along the length of the fret, so as to lift the fret ends out slightly.
That way if I was going to leave a mark on the fretboard it was going to be the point of the blade under the fret.
Once de-fretted I adjusted the neck to get it perfectly flat and, in my case, did have to sand a little to smooth it out properly.
My understanding is that fitting new frets should be done with a flat neck and they should go in quite easily.
That way the new frets aren't forcing the neck back, or holding it back.
As I said - I'm no pro...If someone wants to correct anything up there I'm more than happy ^.
If you're interested but worried about it get some old second hand piece of crap and refret it for the experience.
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Well it turns out I actually found one of the old frets in a bag of parts in the case and its exactly the same fret tang. So it's not all the frets. However I probably did make a mistake in that it sat without tension for a long time while I worked on the body and then put it away for the summer. I didn't recheck the neck, it was fine when I stuck it in the closet. Pretty stupid.
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Just to cap this one off, I did finally get the neck fairly straight by adding a new nut and saddle, stringing it up with a heating pad on it for the past 3 weeks, with a lot of tension on it lol.. Levelled, crowned and polished the frets. Singing like a bird now but I also have new tuners and bridge pins on the way.
Steenamaroo
...
Nice work!
Glad to hear it all went well.
There's little more satisfying than a job like that working out as you hoped.
Glad to hear it all went well.
There's little more satisfying than a job like that working out as you hoped.