Fender Jazz neck bowed

[James G]

I bought a Fender Jazz off Ebay "MY MISTAKE" anyway I noticed the neck was pretty bowed so I took it to the local guitar repair guy I use alot, he got it better but wasnt what he liked and the strings are pretty high up because of the bow, my question is, is it possible to repair the bow by clamping it to a flat surface to where its flat and apply heat from a heat gun etc up and down the neck? or leave it clmaped with heat lamps on it for a matter of time. If this is a way of re[pairing it how many days should I do it? Thanks guys.
james

[jazzyitalian]

No...a heat gun won't work. You might be able to take it to a luthier to see if heat lamps will work. But that's a gradual process and there are never guarantees.

The rod may be busted in which case, you'll have to buy a replacement neck.

Jazz

[James G]

The rods functioning properly. I have nothing but time so I may try the heat lamp thing, maybe light it up with about four lamps and heat the heck out of it for a few days and then let it cool down the at its own. Got nothing to lose... I'll let everyone know how it goes.

[Pilgrim]

I've tried this and you have to be very careful...and it may take a few weeks or longer.

Remove the strings - remove the neck - loosen the truss rod - clamp the neck into the appropriate position, which may be one of your most significant challenges, and do not twist the neck. Pad any clamps so that you don't mar the wood (ACE hardware carries some small rubber sheets about 5" x 5" used in plumbing that make good firm pads between clamps and wood). Set up one or two heat lamps and make sure that you have light fixtures that are rated for the heat - the base of those lamps gets REALLY hot, and you can fry the light fixtures. (I didn't check this and completely fried one of those clamp-on work lights - the base fell apart when I turned the lamp off, and the whole light could have failed!) Also, make sure there's nothing in the area heated by the light that could catch fire from being exposed to the heat lamps for hours.

Don't get the lamps too close - about 8-12" is good. You'll probably want to do this either in a basement or garage workshop, because it's going to be set up for some time.

Then be patient. I did this to correct a twist on the neck on a Kay bass but it took about 3 months! And I over-corrected, so I may have to heat it again and go back the other way. don't forget that you have to figure the wood will spring back at least a little bit when you remove the heat and release the clamps. I just over-compensated.

[jazzyitalian]

Hey back...Pilgrim has just given you a very complete and accurate description of the process. It is very involved. The two items he didn't mention which should be obious:
1. Make sure you have plenty of extra bulbs.
2. Budjet your utility expenses accordingly because your electric bill is going up.

[GlennW]

You can do it in one day with two heat lamp bulbs from HD. The bulbs and the holders (the kind construction guys use) will cost less than $30.

[JustDavid]

Originally Posted by GlennW

You can do it in one day with two heat lamp bulbs from HD. The bulbs and the holders (the kind construction guys use) will cost less than $30.

I've not done the procedure, but one day seems incredibly fast on something we recommend 1/4 turn of adjustment a day.

[GlennW]

The heat allows you to reshape the wood, to a degree. That is, you back the adjusting nut way off, jig/clamp the neck to give a slight backbow, let it it heat for 6-8 hours during which time the wood fibers become soft and are reshaped to the backbow, turn off the lights and let it set over night while still clamped. During the overnight cooling the wood fibers take a set. It will go back to the original shape a little, IOW if you have a 1/16" backbow while it's hot and let it cool you wont have a 1/16" back when you remove the clamps. You might have to give it another session or two to get it like you want it.

The goal is to have a straight neck, or a neck with a slight backbow, when there's no pressure on the adjusting nut and no strings on the bass. That way all the adjusting nut has to do is counteract against string tension instead of fighting string tension and a bowed piece of wood.

62Bass, who posts here, explained the process to me and I've had success on 5 or 6 necks.

Thanks again, 62Bass.

[James G]

I pretty much had in mind exactly what you told me to do with the exception of "the time frame" when to add heat and when to turn off the heat, very very helpful stuff, THANK YOU! Im sure others with my problem will also find this very informative, Im going tomorrow to get a couple heat lamps and some hard wood to use for clamping. I think I got it and I'll let you all know how the process is going.

Thank you all again.
James G

[GlennW]

You're welcome. Here're a few more things that might help.

The heat lamps I use are "clear 250 watt", found at HD. I like to set it up with the head and the heel of the neck setting on chairs, fretboard up. The light pattern is like shining a flashlight at a wall, like a big donut. Situate your lamps to get the most of the neck you can in the brightest light (see pic).

Set your clamp/s so the neck has a slight backbow. The pic shows how I do it, but that's by no means the only way. Set it up so you have enough clearance to lay a framing square (or something else thin and straight) on the frets, that way you can "read" what's going on.

You DON'T want it so that the square only rocks on one fret; as if the square will touch the 1st and 6th fret, then rock on the 6th fret and touch the 6th and 20th frets.

You DO want to induce an arc; as if the square will set on the 1st and 5th fret, then rock and touch the 5th and 8th frets, then rock again touching the 8th and 20th. Those frets aren't "the ones", but you get the idea.

Once you're set up, start with your lights about 8" or 9" from the neck, use a tape to measure this. Pay attention to the finish on the neck; you don't want it to bubble. If after a 1/2 hour or so move them to about 7"; watch the finish. It'll get hot. I think I usually end up with them about 6 1/2", but can't say for sure. You want it almost as hot as it can get without messing up the finish.

Check the arc with the square. All this has been foreplay. Start your 6-8 hours of cooking once it's hot and set up how you want it. If you need to move and/or tighten the clamps do it. You don't have to stare at it all day, but it does need to be monitored.
Don't panic if something doesn't look right; keep it hot and make the necessary adjustments. While it's hot it's like "putty in your hands".

[James G]

Well I bought the amber lamps, didnt know which ones to buy. I set mine up a little different but I am right on the distance and I made a small jig to put the neck in. I been checking on it often and its pretty warm. I measured and put the backbow at 1/16 of an inch, so far so good. My body end of the neck is resting in between the frets so its resting on the fretboard and not the frets, the other end is resting where the nut goes. I made good use out of the mic stands too. I opted to go with the hose clamps that have a heat proof wrap section that sits atop the bottom of the neck, you can see them in the pictures, this way I can easily adjust the tention with the turn of the screw.
Thanks for the info too.

[GlennW]

If that was mine I'd regroup and have it so the bright light is focused on the center 1/3 of the neck as I illustrated. What you have now might work, but I wouldn't bet on it...then again, I've never done it that way. Good luck.

[JustDavid]

What prevents the neck from bending the frame instead of vice versa?

If you wanted to direct the heat away from areas you could shade them.

Just ideas. Good luck with!!

[James G]

The magic marker mark on the neck between the two hose clamps is where the bow "WAS" I did two heat cycles and cooldown cycles and the second cool down I adjusted the truss rod and the neck went straight. I was pretty happy with my results, I checked it when I got home after about 6 hours of setting with the strings on it and at a440 and its still straight as an arrow, I was lucky, its plays really sweet the action is low I had one buzz on the 16th fret a string so I raised the saddle a tad and NO buzzes. Thanks for the help guys. The arrows in the pictures are where it was bowed the worse. I am fricking stoked guys! Thanks a million!!!!!!!!!!!!

[James G]

Originally Posted by JustDavid

What prevents the neck from bending the frame instead of vice versa?

If you wanted to direct the heat away from areas you could shade them.

Just ideas. Good luck with!!

I compensated for the frame bowing also, both neck and frame bowed a tad, the jig is glued and screwed. However it worked!!!! Oh I did the adjustment at 1/16" at a time the worse of the bow was just a little over an eight inch Thanks

[rdpbass]

Good job!!!!!!!!!!!!!!!

[James G]

Well crappers guys, I put the bass away for a few days and when I went to play it I noticed the strings had raised, enough to where Im going to redo it again. I was hoping for a quick fix and it looks like thats NOT the case, I will disasemble it and start all over again but this time with much much more patience. Seeing how its 2 degress here in Ohio I may move the jig inside the house this time. I will keep you posted.
JamesG

[dennispotter]

For what is't worth, I'll post this. In the gunsmithing business, we sometimes bend a shotgun stock to adjust the dimensions to the shooter. The bending is done at the wrist of the buttstock, which is about 1 1/8 inches wide and maybe 1 1/2 inches tall. The technique is to use cotton (not synthetic) rags wrapped around the wrist area (where you would grip the shotgun), tie up with string. These rags are saturated with oil, some use raw linseed oil, it's traditional, but a lot of people now use cooking oil as it smells a lot better. Like french fries. Anyway, heat is applied to the oil soaked rags. Some use heat lamps like described here, other, like myself use an electric heat tank to heat the oil and drip it over the rag area. I have not used lamps, but a lot of gunsmiths do. The oil only serves as a heat transfer medium, rather than direct contact, to minimize damage to the finish. When I do this I heat the oil to about 400 degrees F and dribble (scientific term here) it over the ragged area for about 20 - 30 minutes before applying any force to actually do the bending. I apply the force gradually; over 10 minutes or so, oils still flows (collect used oil ad put back in heater and let flow) After ten minutes or so, when you have the amount of bend you want, you can shut down oil flow and let the whole thing cool down. I like to leave it over night. Yes, you do get some initial spring-back, which is hard to estimate, but this is a permanant bend. Now this heat can do some damage to the finish and touch up may be needed. My personal opinion is that the moisture in the wood is what is heated and allows the bending. This much heat on a guitar neck is probably severe, especially for the finish on a vintage instrument as you are probably going to mar the finish. Only experimentation here will tell. I have a 69 P that I am trying to straighten out myself, and I don't want to damage the finish, obviously. I am not sure what course of action to take as yet. I only post this to contribute to the bending process. But heat will allow one to bend permanently the wood. I had posted about what kind of glue that was used to glue on the rosewood fingerboards, as I suspect the fingerboard in working against the bend, and against the truss rod in making an adjustment. A question,: do maple boards develop this up-bow as much as rosewood?

I would suggest anyone trying this to use a heat lamp and proceed carefully. But it does need to be HOT to bend.

[James G]

I know I am going to take slow steps and document any changes in more detail, and be more patient. I have confidence it will work if i do it right this time.

[thisSNsucks]

Does the Truss rod work? If it does, why dont you just remove the truss rod nut, add a few washers, then put the truss rod nut back on and then try to adjust it?

Seems like going to heat lamps right away was a bold move IMO.