Refinishing a damaged Koa / Mahogany Soloist with Tru-Oil (by a beginner)

Any fellow Brits here will know that last night's weather was very 2020 (as in weird, uncomfortable and unexpected).

With a temp of high 30's and close to 100% humidity it felt like Atlanta here, not the UK. While ATL has air con, and buildings designed to stay cool, here our buildings are designed to stay warm. Needless to say it was impossible to relax, sleep, do anything useful without sweat pouring out of my eyes.

As you may have gathered from the whole grain picking that went on, I can be a tad obsessive and like things just right. Alignment of my pickups is something that has been giving me nightmares. In the past all the screws have already been there for me, I've never had the responsibility of getting that straight, and that posed a few issues to me in how to do that.

You see two trains of thought here, get them straight to the guitar or straight to the strings. I thought long and hard and as I may change pups, straight to guitar is probably the cleanest (and works with my OCD).

So how do you get them perfectly straight to the pup routs when the ring obscures them? Centre lines? Could do, but I thought of another way while I was planning to mask the body (to avoid scratching).

You see as the tape I have is fixed width, if I laid it straight along the edges of the routes I could then measure the edges of the rings to the edges of the tape, mark my screw holes and then confirm the measurements of the holes with the schematics I have for the rings to confirm. That's what I did and yep, it totally worked.





As for drilling the holes. I did the common sense approach of measuring the screw core and finding a drill bit that size and practicing on a scrap piece of wood to make sure the thread wood bite. For my screws I used a 2.34mm drill bit (that's I'd bought for the tuner location pins).

Used tape on the bit etc. etc.

Now, don't go taking the mickey, but my dremel's slowest speed is too fast for this, and my hand drill is a bit big so I opted to take it slow, and old school with a hand drill. Never really used this before despite owning for years but my feedback is that I should use a handdrill more often, far easier to keep straight and in control and ended up making some very very neat screw holes.




And how does it all look?




May seem trivial to most, but this step (and doing the tuning heads) straight gave me more anxiety than anything else. I think I must be on the spectrum.

Finally, it appears being diligent with tolerances pay off (even getting the pups nice and straight within the rings) as the strings are perfectly straight on the poles too. Success!

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Getting everything straight and square goes a long way toward improving the overall look of the guitar. Good job!    :icon_thumright:

Carry on being trivial, it's the way to good results :icon_thumright:

I am not in the UK at the moment but it ain't half hot mum.

I've had a bit of an idea.

I was gonna add some resistors to the coil split circuit to let some of the coil still through even when split (PRS style). Those resistors are usually 1.1 and 2.2k, but people do mess around for different tone and values. Also they're not usually used with the really hot HFS (15k) and VB (8k) so I'm unsure how / what values to use and so would take some experimentation with different resistors.

Then I had an idea, rather than use resistors I'm gonna get two pots (a 10k and a 5k) and put them inside the control cavity inline, then I can configure the split resistance anywhere from 0 - 5k (or 10k for my hot bridge).

Plenty of room in the cavity for two pots and would be quite a cool hidden feature. The outside switches would still do the switch on / off, but you wouldn't be set to whatever the resistor value is, you could flex that ground circuit to whatever sounds good, put the panel back on and then just use the switches until you fancy a change.
Welcome to what is probably the penultimate update for this axe. I have been kind of busy.

With all electronics in hand I was making a nice little template from cardbaord but tbh I find soldering quite difficult, cardboard moves about and getting measurements right can be tricky, so.... to make my life easier I 3D printed this little soldering rig that had the controls already spaced appropriately (well the concentric pots, the switch and the jack).

You'll notice the 2 other pots and the switches. They dont really form part of the main circuit so it's really just a holder for them. Has to be soldered in situ.


As I've mentioned, this will have quite a lot of custom electronics. Plus the addition to concentric pots (with volume bleed caps) adds a bit of complexity so I sketched it all out, and decided to try and get the pots and their caps soldered up before adding to circuit.


Meanwhile I remembered that my 3d printed covers weren't shielded. Luckily shielding paint actually adheres to PLA quite well.


So after a lot of headscratching, and some tricky situations with the caps on those pots (see plectrum for scale) I got the bones of the circuit wired up. I was using my new funky tiny TS100 soldering iron. Man that makes things so much easier.

Also, I always thought flux was for cleaning older boards and reflow etc, but I've learned here that a dab from the flux pen, even on new joints can really get that solder flowing faster and avoid component overheating. I did a lot better here than expected.


You may be asking, what are the two white wires for. Well they're pickup live. I know I could just add the pickups directly but this circuit is sensitive and on those pots the volume live lug is like 1mm and already has 2 wires soldered through it. I decided to join a cable to it and this way should I swap pickups, or do anything really I don't have to go anywhere near the pots. In fact that is my ethos throughout all the soldering I'll be doing. Not so much tidiness, but modularity.

Should anybody be mad enough to use concentrics like this, bare in mind the circuit is much easier if volume is top knob (bottom pot), otherwise you're going to have quite a hard time getting your iron and wires in place easily.


I'm so glad I planned and redesigned this part. Without the channel the wires would never have been able to get into the hole. Seems obvious, wasn't so much before.


Woop we're getting there. Not too bad considering the complexity of the components.

Due to the size of the pots, didn't seem sensible to use that as a ground junction so I used my old method of creating a temporary (which will never be replaced) "ground king" (like a rat king).

This is dirty. Effectively from the switch ground (which is connected directly to jack ground also known as "ground") there is a single wire that runs to the king. The pot grounds are attached to the kind. Then the pickup grounds are twisted together, soldered and then soldered to the king, the tremelo, soldered to the king, the new coil tap circuit, also soldered to the king. It's a big old ball of groundy goodness lol.  I probably should have used a washer or something but tbh it works.

Now the crazy inside pots and coil tap, let me explain the logic. On a PRS Tremonti / any PRS single cut that uses this kind of config, which is largely what I based the core here on, when you tap the neck pickup there's actually a 1.1k resistor in place to feed back in just a little of that tap (or rather not allow that to escape to ground), same for bridge but at 2.2k.

These values of course though could be varied, with a variable resistor, also known as a potentiometer. So that's what I have here. a 5k for the neck (which is a VB pickup, with a single coil resistance of about 3.5k, total 7k) and a 10k in the Bridge pot for the  HFS (with a single coil of about 7k, total 15k).

Theoretically I can have that resistor at 0, so full coil split, 1.1k / 2.2k (as PRS) or full, and so effectively not grounded. The key word here is theoretically. Will it work, no idea worth having a try. Worst case scenario is I pull the pots and add resistors. As I mentioned it's an entirely separate circuit and the pots are held in with mounting tape. I'll tidy the wiring when all confirmed working.

OK so we're close now, real close. Next update will be setup and glamour. SO EXCITED!

I'm strangely really happy and a little upset about this part coming to an end. It's hard for me to articulate what this guitar actually is. It's not so much the salvaging the good from bad situations, it's more how it's given me so much to do, and so much escape from the consequences of Covid. The hours of cathartic sanding, picking out grain, oiling, grinding, reading. It's given me so much distraction from the difficult times both internationally, but also personally.

When I was sanding this thing down, it was as much about having something to do in lockdown and getting some space physically and in my mind as it was about refinishing a guitar.

What's also been super cool is ever since buying this body from Paul (Nexrex), we've stayed in touch, we probably chat about guitars every day. He lives in Aus, I'm in the UK so in reality we kind of update on our projects 1/2 times a day and it's been great sharing the journey. Especially as this was his body which he had some connection to (he had it custom made), that it got lost and then damaged in transit, and that then some mental British guy started taking 80 grit sandpaper to it.
It's coming along nicely. That 3-D holder for wiring things was a good idea. Nice work. Looking forward to the finished pics.
quote author=Dr Excess link=topic=31762.msg451820#msg451820 date=1598006938]

As I've mentioned, this will have quite a lot of custom electronics. Plus What's also been super cool is ever since buying this body from Paul (Nexrex), we've stayed in touch, we probably chat about guitars every day. He lives in Aus, I'm in the UK so in reality we kind of update on our projects 1/2 times a day and it's been great sharing the journey. Especially as this was his body which he had some connection to (he had it custom made), that it got lost and then damaged in transit, and that then some mental British guy started taking 80 grit sandpaper to it.

Always a pleasure to help out mate, great to see she went to a good home,  and its coming along so well 😉👍
Looks great! Congrats on a fine job. :icon_thumright:

Are those full comics or just scanned images of the covers? I see a couple of the first Luke Cage issues when he was called 'Hero for Hire'.
Outstanding Sir, you should be very proud of your efforts. I entered the Navy right out of high school, while I was gone my dear Mother helped me by tidying up my room and in doing so threw out my comic books, including the entire first year of both Spiderman and Daredevil.  :sad1:
Thanks Fellas!

re: comics, grew up on comics and just love the whole art aesthetic. I'm not a massive comic book expert or anything but I do have a bit of a soft spot for some retro DC and have a fairly decent collection of early editions of this and that.

Loving the guitar, can't get over how small and light it is compared to my Strat or even my PRS. I need to weigh it.

Finish isn't 100%, but if I take myself back to picking the white bits from the grain I think it's pretty good all things considered. Also Tru-oil is as repairable as I hoped it to be (don't ask how I know).

I think my biggest learn here is how nicely engineered the VS100 is, it's clearly been designed by an engineer who plays guitar rather than a guitarist who can do some engineering. It's a very slick thing. Coupled with the Sureclaw (which is exorbitantly expensive for what it is) it really is the best setup I've certainly ever owned / seen. Adjusting your tremelo tension via an allen key is so much easier than fighting with two wood screws lol.

I was wondering if the concentrics would be easy to get used to. I think they work great. Took all of 5 minutes for my brain to rewire itself but it's second nature now. Its a shame the full sized version also have giant knobs (which look dorky), but these mini's surprisingly do a nice job and I've no issue with quality of output, although the volume (top) isn't quite as smooth as the bottom yet, still needs to be worked in as it's effectively held in place with a spring clip on the bottom which has friction against the bottom of the pot casing. A little lube there though made a ton of difference though.

Still yet to split the coils in practice and certainly haven't made any resistance changes. I think that area of functionality was more of a "because I can" than a "because I should" but I guess that's still a good enough reason. All good skills to learn.