Options for neck with too much relief?

[lark_z]

I found this Yamaha RBX260 leaning against a dumpster in February. Been happily playing it since then, even though the setup is lacking. There's just too much relief in the neck. The plan (here - "P-Yama" - Second Build - body only) was to use this neck on my second build. I'd really only be out a few bucks for a pickguard and would strip everything else from the Yamaha.

Since I finished my first build, it's very apparent that the Yamaha neck just isn't as good as I thought. First bass was a late 90s Squier P-Bass Special (PJ with J neck) that always seemed to me to have a bit of a ski jump. Point being - the new build neck is likely the first time I've really played a decent setup.

So - to the issue at hand. I take the neck off the Yamaha. Remove the truss nut. Drill out two nuts that will fit into the truss rod recess and install both nuts on the rod. Then I clamp the neck at both ends and really go at the one clamp until I get the neck to a back bow of maybe 0.25". Then tighten the truss nut as much as humanly possible, short of hitting it with a hammer. Unclamp it and the neck is pretty close to flat. String it up (Ernie Ball rounds .050-0.105) and the relief is still pretty bad. Almost 2 mm (~0.075) with the E string fretted at 1 and at 22.

I guess I'm to the point that I just punt and get rid of it for (likely) next to nothing. Are there any other options? BTW - money is definitely an issue.

Thanks

 

[dwizum]

Build your own! Necks are cheap in terms of material, especially if you can strip the tuners off the old neck. You're out maybe $10 for a truss rod, $8 for fretwire, a few bucks for a nut, dot marker plastic, finish, and whatever you need for wood. The rest is just time and effort. Fretting and neck shaping can seem intimidating but it's a lot easier than it looks once you get the hang of it and you can get by with a few cheap tools which you may already have vs needing to buy the "real" luthier tools.

Or you can try to heat-set that neck. Clamp it with a reverse bow like you did, and expose it to low levels of heat for several hours (I've seen people use a 100w incandescent lightbulb). At this point you don't have much to lose.

 

[lark_z]

Interesting....

I'm sure I've seen a steam chamber at the community woodshop. Looks like a big piece of PVC pipe, maybe 8" diameter. If I can figure out a means to clamp it in a backbow and steam it in there, is that an option?

I hear you on making a neck, going to have to really ponder that. I'm afraid I'll end up in wood tool GAS.

 

[dwizum]

I wouldn't use steam personally - I'd be nervous about impacting the glue joints and/or finish.

Then again I've never heat-set a neck...

 

[T_Bone_TL]

Interesting....

I'm sure I've seen a steam chamber at the community woodshop. Looks like a big piece of PVC pipe, maybe 8" diameter. If I can figure out a means to clamp it in a backbow and steam it in there, is that an option?

Standard methodology for steam bending would be to prepare and test your clamping arrangement, steam the wood, remove and quickly clamp, come back in a day or three and unclamp; rather than trying to clamp and steam. However, the impact of steam on glue is a concern, and steam-free (dry) heating is more common in luthierie.

 

[Tim Barber]

Or you can try to heat-set that neck. Clamp it with a reverse bow like you did, and expose it to low levels of heat for several hours (I've seen people use a 100w incandescent lightbulb). At this point you don't have much to lose.

I've done this. Well, actually, I overshot and ended up with a back bow . The theory is sound though, you just want to heat-soften that fingerboard glue line until it will slip a bit. I used careful application of a clothes iron, just getting it "slightly uncomfortable" hot - not "ouch" hot - and then clamping until completely cool. YMMV and not all types of glue respond as well.

 

[lark_z]

Thanks all. I think I get it. Steaming is for raw wood, not a glued neck/fretboard. Dry heat may be an option. Pondering for a few days. Thanks.

 

[lark_z]

I'm going for it. I loosened the truss rod, then clamped it in a back bow. Went at it for 10 minutes with a hair dryer (the boss would have a coronary if she caught me carrying her quilting/sewing iron into the garage). Then I decided to put it in the attic, still clamped. It'll be almost 90 here (central TX) today. I figured if leaving an instrument in a hot car trunk for hours causes too much relief, maybe one afternoon in the attic at >100F might work to straighten it.

 

[cholyoke]

Good luck! I used a clothes iron set to polyester to heat treat an old fender neck. Worked like a champ.

 

[dwizum]

Good luck! I used a clothes iron set to polyester to heat treat an old fender neck. Worked like a champ.

Definitely want to set it to polyester if the neck was from the 70's...

 

[cholyoke]

Definitely want to set it to polyester if the neck was from the 70's...

Lulz. Those thin Geddy jazz necks are gonna need to be reset after a while.

I have no idea what temperature the polyester setting corresponds to, but it is the last setting before the steam settings start on my clothes iron. Unfortunately, the people that make clothes irons don't have a "relaxes wood glue" setting. You might be able to get away with a lower setting. It did darken the clear coat on the maple fingerboard on a neck I did recently. Not totally brown, but very slightly darker than the rest of the board, like it was specially aged. I'd use lower temperatures in the future when doing this treatment to a finished fretboard.

Maybe a hair dryer works better, but I don't have one of those and don't want to use my heat gun.

I also put a 1/8" (~3 mm) layer of aluminum on the fretboard before clamping to help distribute the heat.

 

[rojo412]

I frequently set necks with too much front bow into what I call a "torture device." It's just clamping the neck to a bench with some blocks to hold it up on both ends. Here's a recent victim of it, a Heartfield DR6 neck for @rogerbmiller ...

Same process you guys described, a hair dryer and time (no, not the creme brulee blowtorch seen in the pic). This one came out really nice with a couple of days of minor torture.

 

[lark_z]

Unclamped just now. It's dead flat with the truss rod loose. I'm not convinced it's enough, so it's back in the attic for another day. I hit it with the hair dryer again for 10-15 minutes. Started thinking about using the heating pad, as it could be wrapped around the neck.

 

[rojo412]

When you unclamp, give it almost a day to come to rest with no tension. I've had these come out looking straight at first, but curve again once freed.

 

[Arie X]

if this bending thing doesn't work out 100%, it's possible to pull the frets and re-level the board. might get you where you need to be.

 

[lark_z]

if this bending thing doesn't work out 100%, it's possible to pull the frets and re-level the board. might get you where you need to be.

When I saw this (Baileigh Edge Sander) at the shop today, I thought about just that. Pull the frets and nut and go to town on this bad boy. We'll see. Redo-ing frets scares the heck out of me.

 

[Arie X]

on a free dumpster bass neck what have you got to loose? fretwork requires a small focused skillset, some specialized tools, and a lot of consistency. once you get into it, it's not that hard.

otoh, i wouldn't use that sander unless you have your technique down. an appropriate radius block/s and a contour gage would be a safer choice to start out.

 

[lark_z]

Yeah - I probably wouldn't be happy with a flat neck with no radius. Thanks for the voice of reason.

 

[rudy4444]

Anyone who is using the method of clamping in back bow to remedy excessive relief should be aware that it's a technique that can easily result in loosening the frets in their slots. When frets are installed they are often over-bent slightly so they will be tight to the board when they are pressed or hammered in. If you over-bend the board and they pop up you might run into an entirely different set of problems to deal with.

Sometimes "simple fixes" come with unforeseen resulting problems.

 

[byacey]

Bending a neck with dry heat is the same process as re-cambering violin bows. The wood has to be heated completely through to the core, otherwise it won't stay bent (or straightened) when it cools. To get the heat to permeate completely through, it will take moderate heat (but not enough to scorch the wood, and considerable time. I would estimate at least 3 to 4 hours for a bass neck.

With a violin bow, you can feel it go limp when it's ready for bending. With a bass neck, it will take more force to feel when it's ready. There is always a little bit of spring back, so I would over bend it slightly and clamp it until it's completely cooled.

A medical heating pad set to high and wrapped around the neck should work well enough for this.