WARNING: Super-long post. Please just skip it if you're not interested.
TLDR: Refret and other BTB fixes.
So ... back in June last year, with regard to a newly-acquired 2007 BTB 555 MP, I said ...
the only thing I don't really like is the medium frets. I tend to prefer jumbos and 6105s, and have consequently developed a fairly light-fingered fretting style. If you're playing stiff-ish flatwounds on mediums, you sometimes have to bury the string into the fingerboard to get it to ring true, whereas with taller frets you can just give them a light squeeze, sometimes not even touching the fingerboard. Nothing that a change of fretting style can't adjust for, but I still prefer my J's for that. I'll refret it with 6105 stainless at some point, and then the issue will solve itself, but I'm in no particular rush as it plays and sounds fine with a slight style adjustment.
Over time, the above issue got far too annoying for me and I decided to do something about it. In addition, my eyesight is getting worse as I get older, with the result that seeing the 2mm white plastic side dots in dark conditions / stages was getting increasingly difficult; so, when the family decided to visit some in-laws for a weekend, I decided to solve the issues once and for all.
I got hold of some
jumbo Jescar stainless steel fret wire, removed the strings from the bass, and measured the fret radius. Fortunately, despite what I said in the previous comment, the fretboard is a 20" radius all the way down, so I only needed one curve. I then stripped the bass down and got it ready for action ...
I then used my defretting pliers (just a cheap pair of end-nippers with the ends carefully ground flat and thin) to remove all the frets. Mercifully, when WMI in Korea had put them in, they hadn't used any glue and the slots were not too tight. They all came out very cleanly ...
I then used a field-expedited filing jig and a pair of safe-edge files to 'nip' the ends of the tangs off. Strictly-speaking, you don't need to do this on a non-bound fingerboard, but the originals were done like this and it helps the fret-end bevelling if you remove some mass first, especially with stainless. The de-tanged sections look quite large here, but that's because the frets are oversize; most of the extra overhang is going to get nipped / ground off ...
Frets all cut to length and ready to go. I'm sure I don't need to point this out to fellow BTB owners, but the 24th fret is there, it's just rather ... short.
Kindly excuse the abysmal state of the workshop in the following pics, but I was doing this in parallel with a commission for building a custom-sized 5-bar gate and an outdoor bench, so the place is in mid-chaos state.
I put the frets in by gently hammering the ends into position, then using a fretting caul in the drill press as a fret press. If you ever do this on an already-carved neck, be aware that the neck is going to need some fairly-substantial in-situ support, otherwise you can flex / bend / break the neck / trussrod. Fortunately, I home-tech both my and some friends' instruments, so I have some support blocks already built. I also used walterw's method of using three small strips of fine gel CA glue (one at each end, one in the middle) to make sure the frets stayed down.
Be aware also that using the drill press as a fret press is prone to cause issues with cheaper drill presses. There are multiple reports of people breaking or bending their drill press tables, especially if they're made of pressed metal sheet instead of cast iron. Even the cheap cast iron ones will break under pressure, so be cautious. In the second pic below, you can see a block of wood just below the drill press table. this is a piece of 4 x 3 beam that I recovered from a family member's demolition site. It's been built into a supporting T-bar brace that's exactly the correct height for the 'fret press' table and spreads the load down to the feet of the press and into the floor. My drill press table's probably rugged enough, but I'm not taking any chances ...
I did the fret end nipping and beveling without taking any in-process pictures (sorry), but the results were pretty decent. I used a high-leverage end cutter (
not ground as a fret cutter) to cut them as close as possible and then used an 80-grit carborundum and a 220-grit diamond stone to get them beveled. Stainless can be a beey@tch on files, so I try not to use them for heavy jobs.
I used blue sharpie to aid in the leveling process. I used kovax adhesive-backed 320-grit paper on the bottom of a spirit level as my leveling beam / straight-edge. The process takes longer with 320 grit than with the heavier grits that some use, but I prefer it because (a) it gives you more control (you can stop as soon as the frets are level without taking any extra off) and (b) it cuts down the amount of extra abrasion / polishing you have to do to get the scratches out as the scratches are already somewhat fine to begin with. The fret rocker confirmed when everything was dead-on.
After getting the frets level, I taped-up the fingerboard and used a pair of single-cut triangular files (bahco 186 series) to do the fret crowning. The files have had safe, rounded-smooth
corners ground into them with a bench grinder. This prevents / reduces the files biting into the fretboard during crowning and end-rounding. After I had the frets decently crowned and the ends rounded, I used good-quality wet-and-dry paper and went up through the grits (400, 600, 800, 1200, 2000) to polish them smooth. I didn't bother buffing them this time as I could both see and feel that they were already smooth enough after 2000-grit. The flatwounds can finish the burnishing process ...
With the re-fret pretty-much finished, it was time to deal with the side dots. I decided to replace the 2mm dots with 4mm aluminium
tubes that had a 2mm bore. The idea was that I would use the tubes as the 'major circle' and then fill the inside of the tubes with strontium aluminate crystals ("glow-in-the-dark powder") and low viscosity CA glue. This idea came from Highline guitars and he has a good video on it for more information. The great thing about this is that you end up with a 4mm dot even if you never use the luminosity feature. You can also re-up the strontium aluminate if you want to (in a decade or so) by drilling out the CA and re-packing it.
Given the edge thickness of the fingerboard, to get the position correct, I had to start the drill roughly 0.5mm above the bottom edge of the existing dots so that I didn't stray too far into the maple neck. I used a bradawl to make a starting hole in each dot and then used a 2x6 as a jerry-rigged right-angle jig. It worked surprisingly well. The holes themselves were drilled with 4mm brad point bit at something approximating the right speed.
I then used a spare piece of aluminium shim stock to act as a cutting guard and used a small modelling saw (zona) to cut the tubes almost flush.
You then alternately pack the tubes with strontium aluminate and CA glue. This needs some care and patience as the powder will almost insta-cure the glue unless there is excess glue. It's a good idea to fill the tube up to
just below the surface of the neck wood and then fill the rest with CA glue. This ensures there's a thin CA 'cap' over the powder-glue composite. You can't see it in these pics, but I drilled 4mm holes in a strip of blue painters' tape and put the tape over the tubes when I was doing the packing job. This way, even if you over-flow, no CA glue gets on the neck -- very important! It's also useful to have CA Accelerator to hand if you do this job. It stops things running and can ensure things are solid.
I then used files and sandpaper to bring the dots down to level.
You can charge up the strontium aluminate from any light source, but UV light is especially effective. In normal circumstances, I usually use a bright white-light flashlight but, in this case, the suppliers of the strontium aluminate also sold a reasonable UV LED keychain light, so I used that to charge the powder and test it out. If you charge the dots for about 10 seconds each they stay visibly illuminated for about 55 mins, although the light intensity fades constantly during that time. At 3 seconds each, you'd get about 35 mins. For a gig, you'd have to recharge at least once.
Fortunately, in my case I don't even really need the luminosity. Increasing the side dots from 2mm to 4mm (double the radius, four times the area) and, with the aluminium tube itself reflecting more ambient light than the previous white plastic dots, the markers are already readily visible in the contexts where I was previously struggling. The glow-in-the-dark stuff is a bonus.
WMI used some kind of polyurethane / polyacrylic on the neck, and I'd slightly caught the neck with the sandpaper here and there, so I bit the bullet, smoothed the transition between the fingerboard and the neck, and recoated the half inch nearest the fingerboard with wiped-on water-based polyurethane. I sanded down between coats. The interesting thing about the matt finish on the neck is that 600 grit was too smooth -- the poly was noticeably shiny and smooth enough to be tacky. The correct texture was somewhere between 400 grit and 600 grit (nearer the former than the latter). Immediately after I did it, the poly was a little bit gummy, as it tends to be, but poly essentially keeps curing forever and, after a month (I did this about 5 weeks ago) it's absolutely fine. I know from experience on another, similar, neck that it'll take about 4-5 months to harden to the point where you can't tell the difference, but that's just the nature of this domestic-grade formula. If I'd used 2K, it would be back to normally rigid within a week.
The supernaturally sharp-eyed among you may notice that the machine heads are different in this final pic. That's because, as I was restringing the old ones, I noticed two of them were worn and slipping badly. I managed to re-condition one of them but the other was sadly beyond repair. It was only the string tension that had been holding them in the correct orientation for function. It also turned out that, perhaps unsurprisingly, the Korean BTBs didn't use genuine Gotoh tuners. They used the local made-under-license ones from JinHo (who make some of the Wilkinson stuff). So I bit the bullet and ordered a full set of genuine Gotoh replacements. Unfortunately, this meant that I lost the sick-looking bead-blasted-style finish that is also on the matching knobs and had to settle for regular chrome but, on the up side: genuine Gotohs. The difference is not remotely close; it's night and day in terms of feel and stability.
I also used the hiatus to make a brand-new nut out of TUSQ plastic. This was also an additional improvement.
Anyway, I cleaned / oiled the fretboard and strung her up. She's been playing beautifully ever since and the jumbo frets make playing a joy with stiff flatwounds.
Back in business:
