Fretting - How Much Wider Should Barb Be Than Slot? Also, Crack Question

[Robbie Collins]

I have an HD-28VS in for re-refretting and crack repair. I am charged with undoing someone else's work.

Fretboard:  Previous repair person chipped up the fretboard (40+ fills), widened the slots to .024", and left the fingerboard with an S-curve.

I am using StewMac #0141 fretwire which is .095 x .045. The tang is .020 wide and the tang plus barbs is .036.  Recall the slot is now .024".  My first step was to see if the fret would hammer or press in as is. Definitely too wide. I used the StewMac Fret Crimper to smash the barbs lightly which brought the tang + barb to .029. I pressed a fret in strongly and there was still a .004" gap under the fret.

Is there an optimal width for the tang plus barb relative to the slot width?

Crack:  Also, they repaired what appears to be an impact crack on the right rear waist. Running my finger over the crack I can feel that while the apex of the crack is aligned the crack is the point of an angle. This suggests to me that a brace probably has glue/debris underneath. The crack was cleated with thin rosewood strips. I'd like to remove these but I  wasn't able to wedge a razor, a small chisel, or a feeler gauge underneath. Should I set a damp sponge on top of the cleats, steam them loose, or should I try purely mechanical methods?

All comments appreciated.

You can see the light reflects differently on each side of the crack indicating that the crack is like a roof ridge with each side falling away.

[Mark Pollock]

I recently dealt with some bendy cracks by clamping the wood to a warm chunk of granite surface plate. I heated it on a gas barbecue (really high tech).

You might first try just getting a very warm flat surface and somehow clamping this cracked part down on it and leaving it for a day. I liked using the granite because it released heat for a couple hours, and didn't cause any damage. This might be enough to flatten the crack out, at least it won't cause further damage. It also would help you avoid having to do any scraping or cleaning in a challenging spot. If it doesn't work, then you could just proceed as normal...

[Luke Single]

I can't be of any reliable help on exact barb width... However make sure they aren't too deep :/ we all forget things now and then.
As for the crack you may try taking your soldering pencil underneath and burning a piece of glue to determine hat kind of glue it is. I would attempt to steam it or heat it a bit if it is a glue capable of being loosened, as you steam it slip a feeler gauge or thin razor blade in there and wait for it to come loose. I imagine trying to chisel it underneath would be quite difficult. But that is another option if the glue is not capable of being loosened with heat/steam.
Be careful if you steam it not to bubble or smoke the Finish on the top side. Keep and eye on it the whole time you are steaming or heating. Heating it with an element or maybe a wide soldering gun or home made peace of metal between the two legs of the gun that is the approx size the cleats.
Again If you have to chisel it you could use a small sharp scraper or curved homemade chisel but that process may take a while but it's better then ruining the finish. Slow and steady wins the race.

[Robbie Collins]

Thanks, Luke. That's a scary thought for me...putting a soldering iron inside a guitar.  But, as I think about it, with the proper safety precautions it shouldn't be a big deal. Knowing the type of glue would be very helpful.

I was thinking about cutting a piece of 1/4" brass to the right size, heating it, and plopping it on to the cleat. Your idea of heating it using a soldering gun with two legs is genius.

A bespoke chisel is definitely in the works.

[Robbie Collins]

I should clarify my tang/barb question.

What I know about fretting, I learned from watching Erlewine's 'Fret Basics,' 'Advanced Fretting I,' 'Advanced Fretting II,' a half a dozen times and by reading and re-reading Erlewine, Teeter, Sloane, & Kamimoto. I've also watched innumerable YouTube videos and read every article on Frets.com. What is difficult about this method is determining the state-of-the-art as well as correcting my misconceptions.

Erlewine and StewMac seem to be pushing a fretting paradigm that includes the neck jig, pressing tools, fret crimper and fret barber. The implication is that matching the tang/barb to the slot is unimportant and, indeed, StewMac doesn't provide this information.

It seems to me, however, that extra work can be avoided by matching the fretwire to the slot. Nothing beats a fret that seats perfectly and stays down. Consequently, I'm trying to figure out the best way to match a fret to the slot.

It doesn't help that I'm also chasing my misconceptions. I think I found another one and you guys probably discerned it in my initial problem description. Several times when frets wouldn't go down or stay down I've thought that the tang/barb was too wide and was wedging itself in the slot like a tapered plug. In each case, the problem was either that the slot wasn't deep enough or the barbs weren't grabbing the sides of the slot. Nevertheless, it seems to be a persistent error in my judgement.

[Robbie Collins]

I did some homework:

Erlewine: 'Guitar Player Repair Guide' ©2007
                 Ebony-.001 larger tang. Rosewood - .002" larger tang. Maple - .002" larger tang.

                'Fretword: Step-by-Step' ©2010. No mention except for compression fretting.

Sloane: 'Guitar Repair' - "Next size gauge for ebony. Two degrees up for rosewood."

Kamimoto: "Fit tang to slot.

Teeter: n/a due to his gluing method.

So, from these masters it would seem that tang width and not barb is what is important. My problem with the HD-28 was that I was expecting vintage Martin fret slot width and ordered the fret wire accordingly. My bad...I should always measure.

I've noticed that in newer editions of StewMac published books that some information is left out. For example, DIY jigs are missing if there is a StewMac jig available. I'm wondering if the Fretwork book leaves out tang sizing for the same reason that tang size info isn't available on the website: because in SM's fretting paradigm, sizing the tang to the slot is not necessary (and would reduce demand for the crimper and fret barber).

               

[Robbie Collins]

Stew Mac tang widths:

PMC is company said to make StewMac fretwire.