Need advice - '73 JS Bass II with a neck issue

[jthrel]

Hello LTG'ers,

I've just located and purchased a '73 JS Bass II. HOWEVER, she has a bowed neck that needs your advice.

First the GOOD. This is a cherry, short scale bass with two Guild humbuckers and the original hardshell case. The bridge, saddle and tuners appear original and the electronics work.

The front of the body has some wear but overall looks good. Note that the hardware store nut on the splitter switch is not correct.

The back of the body has a fair number of "careless" scratches from buckles and buttons.

The lower, back edges of both the upper and lower bouts are kinda’ banged up.

The headstock laminate is intact but a little wrinkled (heat damage I think) and the tuners work well.

Now for the BAD. The neck is bowed as you can see in the series of pics below. Compare the string action at the the 1st fret and 12th fret in the first picture. The action at the 12th fret is slightly more than 1/4". This provides a negligible string angle across the saddles and the bridge is as low as it goes. Yep, the strings pop out of the saddle grooves when the strings are plucked with gusto.

I have not tried the truss rod adjustment as yet but the nut looks like it has been adjusted previously (cracked truss rod cover and a lot of thread rod protruding from the nut already). I’m hauling the bass to a luthier for a consult this week but would appreciate your opinions and experiences with neck issues such as this.

Thoughts? Kudos? Tomatoes? Junk? WHAT! I'm torn between the joy of discovery and buyer's remorse.

Al

 

[fronobulax]

Good catch on the "nut" on the bass boost switch. I wasn't sure you were right until I looked at pics of mine.

As for the neck, you might as well get a pro's estimate. It does sound like someone has been down the truss rod adjustment path before.

I will say that I have found two kinds of people. One kind has to have something fixed if they know it is wrong. The other kind only fixes what makes a difference. There is a dent in your car's door and the repair cost is just about what your deductible is. Do you fix it anyway (first type) or not (second type)? So I have to ask, can you play the bass in tune for the type of music you play? If yes then you might be safe ignoring the bow if your temperament will let you.

 

[Happy Face]

For what it is worth, I'd find that action very aggravating. The action on these should be a lot more friendly. Hopefully there is not a problem with the truss rod itself.

Please let us know what the luthier thinks!

 

[jthrel]

...you might be safe ignoring the bow if your temperament will let you

I am temperamentally (and perhaps genetically) unable to allow an instrument under my protection to continue in such a state. :!: This pretty girl spent most of her last 11 years locked in a closet - waiting on a rescue - waiting on someone to help her sing again. I will have to get this neck repaired or let the instrument move along to another caretaker.

 

[Fixit]

If the truss rod is functioning, looks like all it may need is a truss rod adjustment? What is under the bridge? Did someone put something under to raise the bridge, or is that supose to be like that?

 

[jthrel]

Thanks Fixit,

If the truss rod is functioning, looks like all it may need is a truss rod adjustment

I'm really hoping that the truss rod will do the trick... but there is a LOT to be done. Given the amount of adjustment already done on the nut, I am hesitant to start cranking until the luthier has a look. If the truss/nut is seized or at the end-of-range, I risk splintering the neck THEN I would have to throw myself off of a cliff.

What is under the bridge? Did someone put something under to raise the bridge, or is that supose to be like that

....... What you see immediately against the guitar is the plate that acts as a fulcrum for the bridge and protects the wood from the threaded allen bolts that raise or lower the angle of the bridge. These allen adjustment bolts are the threaded posts immediately behind the rosewood saddles in the pic below. The second (upper) plate holds all of the mechanical adjustment parts of the bridge. Both plates are integral to the bridge.

Al

 

[fronobulax]

If the truss rod is functioning, looks like all it may need is a truss rod adjustment? What is under the bridge? Did someone put something under to raise the bridge, or is that supose to be like that?

Mine left the factory with that "plate".

 

[The Guilds of Grot]

The plate under the bridge is for there bridge elevation adjustment screws to bear upon.

 

[jthrel]

...against the guitar is the plate that acts as a fulcrum for the bridge

For those of us that want to know :lol: a correction to my observation about the JS Bass bridge function. After more creative peeking-about, the fulcrum (axis of rotatation) for the bridge seems to be a pair of rubber bumpers at the far tail of the bridge. The two screws at the far tail pass through the uppermost plate of the bridge near the string anchor then through some rubber washers. This is the axis around which the bridge rotates up and down. The lower plate (against the wood of the guitar) apparently is there to prove a surface to protect the wood from the pressure of the allen bolts and from the bolts holding the intonation positions of the saddles.

A least that's how it seems without an autopsy. FWIW (for what it's worth)

Al

 

[mgod]

Unless the bass is damaged that neck bow is an easy fix and designed to be easy. Now me, having played these damn things for over 40 years, I won't dare do it myself. But that's because of my fearsome prowess with tools, etc. I can still barely change a set of strings, which is is how I ended up with so many basses. But it doesn't take much competence to tweak a neck, if you live near a mildly helpful luthier.

 

[jthrel]

Update on the bowed JS Bass neck........

Had a nice visit with a good luthier yesterday evening. The nut on the truss rod has already been tightened quite a lot - however it does not seem frozen. The length of threaded rod extending above the nut is just at the surface of the truss rod route. We don't know how much more thread is on the rod and there is a LOT of adjustment needed to decrease the forward bow of the neck. We came up with two affordable approaches:

- Hardware store approach - remove the truss rod nut and slip several small washers onto the rod. Reinstall the nut which will then be at the beginning of the available thread. Place increasing tension on the truss rod over several days to allow the neck to accomodate. If the ensuing neck adjustment works, a small piece of the threaded end of the truss rod can be cut off to allow the truss rod cover to be reinstalled. :idea:

- Brute force and barbecue approach - put the neck in clamps and apply an iron. Cook it, bend it and let it cool for 8 hours or so and see if it will straighten out. :!:

If neither of these approaches work, then this bass may have to find a new owner that REALLY likes the notes available at the first 5 frets.

This is gonna take awhile with the backlog/holiday/vacation schedule......... further updates in mid-January.

Al

 

[jthrel]

January Update......

After a couple of gentle reminders, my luthier has begun fussing with the neck of my JS Bass II. As of now, the hardware store approach is yielding modest results on correcting the forward bow in the neck.

- He removed the truss rod nut, inserted a couple of washers to gain some thread length and retightened. This has significantly reduced the forward bow and the string action above the 5th fret is markedly improved. There is some buzz on two strings above the 12th fret. The huge upside is that the neck is still capable of moving , however, the bridge is as low as it will go :? . The rosewood saddles have been swapped around to minimize buzz.

- I provided a set of Thomastik-Infeld flatwound strings (JF324; .043 - .106 gauge) for restringing but these might be too heavy. On the luthier’s recommendation, we are going to try restringing with a lighter gauge and play the bass for awhile to see what happens to the neck.

- I’ll provide some Before/After pix after I retrieve the bass this week.

- If the hardware store approach doesn’t provide satisfaction (and frankly this looks like a temporary fix :roll: ) we will have to go to the NECK IRON – basically a 3 point bending jig for the neck with application of heat. The iron melts the glue between the neck components and allows bending of the wood to occur. The iron is removed and the neck cools off in the jig. There are a lot of interacting factors between the bending jig, the wood of the fretboard/neck and the glue. The luthier sees the outcome of this process as matter of luck with about 40% of guitar necks requiring another session or two of HEAT IT UP AND HOPE FOR THE BEST.

Sometimes guitars need a lot of love…….

Cheers,

Al

 

[fronobulax]

Thanks for the update.

 

[gilded]

January Update......

- He removed the truss rod nut, inserted a couple of washers to gain some thread length and retightened. This has significantly reduced the forward bow and the string action above the 5th fret is markedly improved.

This is a 'fix' that my luthier has used on occasion.

There is some buzz on two strings above the 12th fret.

The buzzing above the 12th fret just means that the fingerboard has 'humped-up' at the neck join. There are a couple of reasons for this, but usually it's just a symptom of the plasticity of wood under 150+ pounds of string pressure at the neck join. The cure is to dress the frets.

The huge upside is that the neck is still capable of moving ,

Great!

however, the bridge is as low as it will go :? . The rosewood saddles have been swapped around to minimize buzz.

Sometimes the necks are underset from the get-go, sometimes the neck has literally torqued-up at the join (actually, the luthiers I know call the phenomenon 'neck-dive', because it looks like the neck is diving into the body at the join. It's a common thing on Gibson SG/Guild JS basses). Usually the fix on the that is to remove the neck and reset it at a steeper angle. My luth' did that for me on a JS fretless I owned a few years ago. In terms of the impact on the lacquer finish, it would be very hard to make that an invisible repair.

On the other hand, if you like the way your bass sounds with the corrected action, I wouldn't bother with a neck re-set.

- I provided a set of Thomastik-Infeld flatwound strings (JF324; .043 - .106 gauge) for restringing but these might be too heavy. On the luthier’s recommendation, we are going to try restringing with a lighter gauge and play the bass for awhile to see what happens to the neck.

I remember thinking that the Thomastik Jazz Flats that you are talking about would be too heavy for my '66 Starfire bass. I thought that, because the string diameters were so large compared to most light guage sets, the tension would be extremely high and my bass would suffer. Once I put the strings on, I realized that Thomastik Jazz Flats are a low-tension string, regardless of the size. It's just the way they are made. Put 'em on, you'll like 'em.

If you don't want to use them and they are unused, sell them to me! I need another set for my Dearmond Starfire Bass (I'd keep them though, if I were you).

- I’ll provide some Before/After pix after I retrieve the bass this week.

- If the hardware store approach doesn’t provide satisfaction (and frankly this looks like a temporary fix :roll: ) we will have to go to the NECK IRON – basically a 3 point bending jig for the neck with application of heat. The iron melts the glue between the neck components and allows bending of the wood to occur. The iron is removed and the neck cools off in the jig. There are a lot of interacting factors between the bending jig, the wood of the fretboard/neck and the glue. The luthier sees the outcome of this process as matter of luck with about 40% of guitar necks requiring another session or two of HEAT IT UP AND HOPE FOR THE BEST.

Sometimes guitars need a lot of love…….

I think that I'd rather re-set a neck than try to re-heat it. Re-heating works, sometimes. It may not be the long part of the neck that needs reheating. It might be that neck has torqued at the body join; 'neck-dive'. In my experience, a neck re-heat won't be able to address that issue. Ask your luthier to evaluate your bass based on those variables, maybe?

Cheers,

Al

Good luck with your bass!

 

[jthrel]

Gilded,

Many, many thanks for the in-depth commentary! Your opinions and experience with this type of problem (forward neck bow) provide me a much better perspective on managing the repair of my JS Bass.

The luthier got as much out of the truss rod adjustment as possible, dressed the upper frets and finished the set up. He then parked the bass on a stand for three days to see if the neck would drift back. I'll be paying him a visit today to evaluate the results. "Before/After" pix to come.

Al

 

[gilded]

you're welcome!

 

[DKB]

I have a '72 JS II that is a house fire survivor. The original Cherry finish was destroyed from the heat and is sanded down but the good news is, all the electronics survived, as did the headstock original finish.

So, the reason I brought this all up is, this bass has the "neck dive" option described above. The bass plays and sounds great until you get to the 12th fret or thereabouts and then it's all pinched off buzzy notes. When you sight down the neck, you can really see it. So, my trusty guitar tech did as much as he could with it but recommended I go see one of the best luthiers in the Chicago area to see if it can be saved / fixed. I haven't been able to go do that because I am sidelined with a broken ankle that is on the mend.

I've recorded with this bass several times already because it has such a good sound for what I am working on and if I don't need to go above the 12th fret, it is serviceable.

It was very useful to read this thread with some of the very good and detailed responses on how to address the neck dive problem. I'd say my bass is a candidate for the iron or neck reset treatments. No worries about the finish, it's mostly all gone.

 

[jthrel]

Before/After Photos. The luthier did a great job with the setup.

- Inserted 2 washers under the truss rod nut to provide more working thread. The rod still required a LOT of adjustment to move the neck - so much that the truss rod protrudes from the route in the headstock.

The forward bow of the neck is improved.

The action at the 12th fret has been markedly lowered. If you look closely, the fret dressing is also apparent.

He also deepened the string notches in the saddles.

The G-string saddle required a lot of lowering - so much that the intonation claw holding the G-saddle in place had to be filed down and the entire saddle shortened.

Bottom Line - I'm still trying to wrap my brain around how a bass guitar is supposed to feel. The new setup is light-years better than the woeful shape she was in when purchased. At the risk of sounding like a spoiled whiner guitar player :lol: , the action above the 5th fret still feels uncomfortably high. I get a lot of "string slap" when I fret the higher regions (the string strikes the fret just a little after I pluck the note - it's a coordination thing).

I'm still considering the neck iron treatment (for the bass, not me). Most of the bow seems to be at the headstock end of the neck starting at about the 7th fret. I'm not seeing deformation at the neck/body joint that would indicate "neck dive" as the culprit. Since the bow is not smoothly distributed across the neck, I don't think a neck reset would really help.

Al

 

[hagmeat]

Thanks for the update, that is a vast improvement. Your luthier has done well.

 

[jthrel]

OK, I'm obsessing over the obvious here.... But to corroborate my eyeball impression of the forward neck bow after the setup, I measured the E string relief at each fret (action) and measured the distance of each fret from the nut. The results plot as such : :shock:

I think a neck ironing will be the next step........ :?


Al