#1
Hello fellow guitar enthusiasts,

I have a 1965 Teisco MJ-2L that is in nice condition and sounds unique but with only one problem - a neck back-bow.

I have already tried to bring it forward by trying the following home-made neck press attempt: clamping it into a forward bow using nylon bands (with an already-loosened truss rod, of course) and running a hot but dry iron on a dry towel placed over the fretboard. This warmed up the fingerboard considerably and was done in hopes of creating the necessary forward bow permanently. It possibly made some slight improvement but not enough.

So now I am considering taking the following more drastic steps, in order of preference/invasiveness:

1) Do the same with the hot iron but use a moistened towel so that steam is injected into the fingerboard, then quickly clamp the neck into a slight forward bow and wait until everything settles and cools. I am hoping this would reverse the bow and then could be fine-adjusted using the truss rod.

2) Perform a full fret job on it, correcting the slight back-bow by a combination of reshaping the fingerboard and further dressing the new, higher frets. [This can only be done for very slight change over what is there and will likely also be insufficient.]

3) Remove the fingerboard (and probably the frets), re-glue it back onto the neck but clamp it using a form with the same slight forward-bow that I want (I have the same form with which I used this technique on my homemade guitars and it has worked, giving two-way adjustment). Then, of course, install and dress new frets.

Is there any advice out there from the experts?

[This guitar is fun, sounds quite good and has *the* best whammy bar design I have ever tried for my tastes (including Fender and Bigsby). I know it is not an heirloom-quality instrument and I do not want to pay anyone to do this for me, but I would enjoy it a lot if I made it play well.]
#2
It's a job for a skilled luthier IMO. None of your fretboard heat tricks will bear fruit as this guitar neck has warped as the wood continued drying and seasoning over many years. It may only cost a few hours labor to get this done by someone with the tools and the talent. Get a quote first before turning that axe into a hopeless science experiment gone bad.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Guthrie on tone: https://www.youtube.com/watch?v=zmohdG9lLqY
#3
Thanks for the input. I hear you - I have some build experience (talent, maybe some), but few exotic tools.

If the job can be done inexpensively by a pro then I will look into that first. If it requires a serious expenditure, I might just take my chances on my own experimenting. As I said, not an heirloom.
#4
It depends on how severe the back bow is. If it's slight, you can correct it with the truss rod. Keep in mind that the truss rod on its own won't bend the neck. You'll need to flex it a bit.

If it's really severe, I would remove the fretboard, clamp the neck to a rigid straight edge (like a steel bar or something), then replace the trussrod with a modern 2-way one and reglue the fretboard. I'm no expert, though.
#5
My inexpert advice would be to try fairly drastic clamping in a warm place for an extended period, keeping an eye on progress, then use heavy strings to stop it creeping back. If it doesn't work, nothing lost except a little time, and you can then take it to a suitable repairer or try more drastic methods. - Heat and clamp worked well to remove excess relief from my old National.
#6
Quote by Blademaster2
Hello fellow guitar enthusiasts,

I have a 1965 Teisco MJ-2L that is in nice condition and sounds unique but with only one problem - a neck back-bow.

I have already tried to bring it forward by trying the following home-made neck press attempt: clamping it into a forward bow using nylon bands (with an already-loosened truss rod, of course) and running a hot but dry iron on a dry towel placed over the fretboard. This warmed up the fingerboard considerably and was done in hopes of creating the necessary forward bow permanently. It possibly made some slight improvement but not enough.

So now I am considering taking the following more drastic steps, in order of preference/invasiveness:

1) Do the same with the hot iron but use a moistened towel so that steam is injected into the fingerboard, then quickly clamp the neck into a slight forward bow and wait until everything settles and cools. I am hoping this would reverse the bow and then could be fine-adjusted using the truss rod.

2) Perform a full fret job on it, correcting the slight back-bow by a combination of reshaping the fingerboard and further dressing the new, higher frets. [This can only be done for very slight change over what is there and will likely also be insufficient.]

3) Remove the fingerboard (and probably the frets), re-glue it back onto the neck but clamp it using a form with the same slight forward-bow that I want (I have the same form with which I used this technique on my homemade guitars and it has worked, giving two-way adjustment). Then, of course, install and dress new frets.

Is there any advice out there from the experts?

[This guitar is fun, sounds quite good and has *the* best whammy bar design I have ever tried for my tastes (including Fender and Bigsby). I know it is not an heirloom-quality instrument and I do not want to pay anyone to do this for me, but I would enjoy it a lot if I made it play well.]


basically none of the steam-and-bend-and-clamp tricks work for very long. the neck will pretty much go back to where it was. injecting water/moisture/steam into a neck swells the wood creating even more back bow

a key question: how much back bow do you have? also a picture would help.

have you considered pulling the fretboard and installing a two way truss rod?

were it mine i'd look at doing the following:

-stabilize it's moisture content. keep it in a room at 45% rh for about three weeks. observe any change.
-pull the frets.
-pull the fretboard and possibly do some planing to the neck shaft.
-install a two way truss rod. i'm guessing there's a compression rod in there. you may have to make a shim for the bottom of the pocket if you have to cut it straight. as compression rod pockets are usually arched or shimmed with a radiused insert.
-level the fretboard.
-re-fret. you're probably going to have to widen the fret slots and glue the frets in if the above tricks didn't make a decent improvement. you don't want to induce further back bow by pounding new frets into tight slots.
-level, crown, dress, and set up.

the two way truss rod should give you a good amount of adjustability, probably on the order of 1/8" to 5/32" i would expect on an installed neck. any more then that after all of these fixes then i don't know.
#7
Agreed that a dual truss install is the best option to save this neck, or cut it off and start over. It seems like a lot of trouble for a Teisco when a really nice, straight, MiM Strat/Tele could be found for $250 used. I guess if you have the tools and the time...

Teisco guitars are strictly wall art for me because the necks and hardware are generally pretty terrible quality.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Guthrie on tone: https://www.youtube.com/watch?v=zmohdG9lLqY
Last edited by Cajundaddy at Nov 19, 2015,
#8
Thanks for the valuable advice, everyone.

The back-bow is pretty small, probably less than 1mm from flat across the full length (it is difficult to measure precisely. It has crept up on me over the years, and as I already maintain a 40% to 50% humidity year round I cannot see what else I can do external to it.

I do not want to be too invasive since it is not a valuable instrument (but I do like its unique, warm tone) and also it is not so bad now that it cannot be played and enjoyed - I am only trying to make it better. It was also my first electric guitar, so it is of sentimental value mostly.
#9
Quote by Blademaster2
Thanks for the valuable advice, everyone.

The back-bow is pretty small, probably less than 1mm from flat across the full length (it is difficult to measure precisely. It has crept up on me over the years, and as I already maintain a 40% to 50% humidity year round I cannot see what else I can do external to it.

I do not want to be too invasive since it is not a valuable instrument (but I do like its unique, warm tone) and also it is not so bad now that it cannot be played and enjoyed - I am only trying to make it better. It was also my first electric guitar, so it is of sentimental value mostly.


oh, ok. less then 1mm is not much -<.039 actually. you should be able to deal with this through re-planing the fretboard and then re-fretting. you will need to deal with the nut also.

maybe i miss-understood, but your post made it sound like it was way worse.
#10
@Cajundaddy

Yes, for this Teisco the machine heads and switches are the weakest parts. On the positives, the body is solid mahogany, the pickups have a nice tone and the whammy bar is the best I have ever tried (comparing to Bigsby and Fender Stratocasters). The electronics are serviceable and are not too bad afterward.

I have used it in recordings when I want its unique tone - to sound different from my Strat.
#11
@ad_works

Thanks. Since the frets are pretty well near end-of-life (and are too skinny for my taste), and the nut is already a bit chewed that might well be the most satisfying option, and leaves the wood shape alone.
#12
Quote by Blademaster2
@Cajundaddy

Yes, for this Teisco the machine heads and switches are the weakest parts. On the positives, the body is solid mahogany, the pickups have a nice tone and the whammy bar is the best I have ever tried (comparing to Bigsby and Fender Stratocasters). The electronics are serviceable and are not too bad afterward.

I have used it in recordings when I want its unique tone - to sound different from my Strat.


Understood. Lots of personal history and a usefulness all it's own. I have a 67 SG that is nearly played out after 5000 gigs but I have owned her since 1970 so she's family now.
"Your sound is in your hands as much as anything. It's the way you pick, and the way you hold the guitar, more than it is the amp or the guitar you use." -- Stevie Ray Vaughan

"Anybody can play. The note is only 20 percent. The attitude of the motherfucker who plays it is 80 percent." -- Miles Davis

Guthrie on tone: https://www.youtube.com/watch?v=zmohdG9lLqY
#13
I've reversed a back-bow, but it took time. I just clamped it to a known straight piece of metal, steamed it (the BACK of it) occasionally and left it for a few months, readjusting the clamps occasionally. Straight as an arrow.

Applying a hot iron to the fretboard side will usually loosen the fretboard glue and/or any glued frets. Not the first choice.