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| Author: | Rocker [ Thu Feb 09, 2006 4:14 am ] |
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Hi. I just made my first neck for one of my electric guitars. Overall, it turned out pretty well and very playable. One thing that bugs me though is it had some initial backbow in it. Luckily, I used a Hot Rod 2-way adjustable truss and was able to set the bow to where it needed to be once it was strung up. The strings don't have enough tension to put enough foward bow in it, so it needs some preload from the truss rod. This is an electric guitar with a 25.5" scale length. I bought the fingerboard pre-radiused and slotted and made sure it was flat before I glued it on. The same for the neck. I clamped it to a perfectly flat hardwood board. The only thing I can think of is either the stresses in the neck wood caused it to bow backwards once it was shaped and thinned down, or something was goofy in my clamping. I modelled it similarly to the Jackson-thin necks which I prefer for my playing style. I actually made it about 0.050" thicker, though. I generally use a 9-42 or 9-46 set of strings, so very light. I laminated the 3-piece neck with 2 pieces of maple sandwiching a 1/2" wide piece of walnut in the quarter-sawn direction. This should be stronger and less warp-prone than a single piece of flatsawn chunk. I want to start on another neck using a standard truss, but am afraid I will have the same problem again and won't be able to compensate with a single rod. Any ideas? Thanks for your help. |
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| Author: | Michael Dale Payne [ Thu Feb 09, 2006 4:29 am ] |
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Is it back slope or bow. In other words if un-stung is the neck set with too much back angle or is there a bow in the middle? if there is a back bow in the middle un-strug then it was there at assembly or is imparted by the fretboard after fretting. I have seen this when the slots were too tight for the fret tangs. causing the fretboard to spread as the frets were installed. |
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| Author: | Rocker [ Thu Feb 09, 2006 5:38 am ] |
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There is a bow in the middle. The frets are a likely possibility, I suppose. But, I got the frets and the fingerboard from Stewart. They didn't appear to go in too tightly, or require excessive force. But, this is my first neck, so what do I know? Purchasing a slotted board is a waste of time if I have to re-slot them. Not to mention a chance for me to ruin it. Has anyone ever ran into this with a pre-slotted board? How do I avoid this in the future? |
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| Author: | Michael Dale Payne [ Thu Feb 09, 2006 6:01 am ] |
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I would not have re-sloted, I would have thinned the fret tang. I believe SM even sells a tool to do this. SM's fretboards are a bit tight depending on the fret wire you use, but is to insure that they will work with a wide range or fret wire. Therefore it will be tight on some and a tad lose on others. Plus there is a upper and lower tolerance on the wire it's self a couple of thousands can make the difference. |
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| Author: | Laurent Brondel [ Thu Feb 09, 2006 8:14 am ] |
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Like Michael says, also what and how much glue did you use to glue the fretboard to the neck? The water from yellow or white glue can help create a backbow also. |
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| Author: | Wade Sylvester [ Thu Feb 09, 2006 8:44 am ] |
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Laurent is correct. Mr. Cumpiano lays a damp cloth on the back side of the neck when clamping to glue the fret board. This way the swelling gos both directions so you don't end up gluing a bow into your neck. It works for me. |
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| Author: | Rocker [ Thu Feb 09, 2006 9:28 am ] |
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So much to learn. I will look into thinning the frets next time. I did not use any glue for the frets. I've read various methods of installing frets from dry to using water as a lube to gluing them in. The frets I used have the little "teeth", so I assumed they needed no glue unless I have an end that won't stay down. The damp rag idea sounds like a smart thing to do. Makes sense since there is quite a bit of glue on the board side. I will definitely do that next time. Thanks again. |
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| Author: | Michael Dale Payne [ Thu Feb 09, 2006 9:50 am ] |
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Glue acts as both a bonder and a lub but does add to the total thickness microscopicly. It is a common re-fret procedure to glue due to the micro opening of the slots when frets are pulled. Also like I said with any extruded material like fret wire there is a min/max tolerance that the material is manufactured to. So if they are on the small side of that tolerance they will fit losser and vise versa. and one end of a roll of wire may be on the low side and the other on the high side, and you will not be notified by the vender as which they are. I always measure the tang so that I know what the fit will be like. |
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| Author: | Rod True [ Thu Feb 09, 2006 11:43 am ] |
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So I've heard of others using epoxy to glue the board down, this would eliminate the moisture issue I would think yes? What else do people use for gluing the fretboard to the neck? I've used titebond 1 and am just experiencing this problem with #4 guitar. The back bow is slight but there, hoping that it will come out with the string tension. So now I'm thinking of doing the frets after the neck is attached to the body after finishing, like Tim McKnight's tutorial on the "jigs, tools & techniques" page. |
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| Author: | LarryH [ Thu Feb 09, 2006 12:16 pm ] |
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StewMac shows a technique where a compensating bow is set into the neck when gluing the fret board. I ignored it and have fought a slight back bow that is now finally relieving itslef from string tension, since I only have a single action truss rod. I won't ignore this step next time. Check page 21 Stew Mac PDF File |
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| Author: | LarryH [ Thu Feb 09, 2006 12:18 pm ] |
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[QUOTE=Rod True] So I've heard of others using epoxy to glue the board down, this would eliminate the moisture issue I would think yes? What else do people use for gluing the fretboard to the neck? I've used titebond 1 and am just experiencing this problem with #4 guitar. The back bow is slight but there, hoping that it will come out with the string tension. So now I'm thinking of doing the frets after the neck is attached to the body after finishing, like Tim McKnight's tutorial on the "jigs, tools & techniques" page.[/QUOTE] I've been fighting a slight backbow on my first guitar and it makes the buzzes SO hard to cure. The string tension WILL take it out with time. I left some medioums on for along weekend and that did the trick. And LMI sells an epoxy just for such things. haven't tried and probably won't but will use the echnique described above. Larry LMI Epoxy |
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| Author: | JJ Donohue [ Thu Feb 09, 2006 12:31 pm ] |
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I use regular hardware store epoxy...30 minute cure stuff. After gluing my 1st with HHG and getting the backbow, I've been epoxying FB's. Lesson learned! |
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| Author: | Michael Dale Payne [ Thu Feb 09, 2006 1:19 pm ] |
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I believe I read where Sir William pre-loaded his truss rod before installing the neck and leveling the fretboard to help eliminate this issue. I need to go back and re-read T&T again, it has been a while and I could be mistaken. |
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| Author: | RussellR [ Thu Feb 09, 2006 8:13 pm ] |
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Your Right Michael He does describe the process in his book. |
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| Author: | Daniel M [ Thu Feb 09, 2006 9:07 pm ] |
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Up 'till now, I have used single acting truss rods & I have had good success cranking the neck back a bit prior to levelling. So far, it has never been a problem for me to get the relief I wanted using this method. String tension usually takes care of it, but once i had to ease the truss rod during setup. |
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| Author: | LarryH [ Fri Feb 10, 2006 2:10 am ] |
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[QUOTE=Daniel M] Up 'till now, I have used single acting truss rods & I have had good success cranking the neck back a bit prior to levelling.[/QUOTE] Daniel, What does "cranking the neck back a bit prior to levelling" mean? And how would one do that? Sorry to be a stickler but I am a bit new and don't know some terms or techniques but am very interested. Larry |
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| Author: | Rocker [ Fri Feb 10, 2006 2:50 am ] |
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WOW! This has turned out to be a great thread. There are some really good tips here and that article from StewMac is great reading. Thanks LarryH. As a couple of people mentioned here, the back bow does seem to be coming out from the string tension with time. Every day I have to retune up about a half step and now it looks like I can relieve the truss rod some. It was nice in the sense that I was able to add forward bow when I went to level my frets at the beginning. The main disadvantage I see with the double truss is unless you cushion the center of the rods well, they rattle when there is little or no tension on it. I did put a little caulk in the bottom of the slot before installing, but didn't think about between the two rods and between the top rod and the fingerboard. That kind of discouraged me from using one again. That, the added cost and weight and lots of material removal all seem to be big disadvantages for my application. I will save any more about the truss for a new thread. Please keep the back bow tips coming. Thanks again. |
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| Author: | Michael Dale Payne [ Fri Feb 10, 2006 3:03 am ] |
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I use the TRSD Double acting truss rod by LMI on 25 guitars now. I have never had a single rattle. Of course, the next one up will now that I have said that   . so far I have had no issues on back bow and I do not preload. I try not to impart any relief if possible. I did have one that I had to remove sone excess relief.
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| Author: | Daniel M [ Fri Feb 10, 2006 4:59 am ] |
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Larry; When I'm getting ready to level the fingerboard, I tighten the truss rod enough that the neck takes on a visible back bow, then I level & arch the board. This pre-stresses the neck so that if the neck takes on a back bow when it is fretted, there is enough built in "spring", to allow it to straighten out again when the rod is eased off. As mentioned, if you use a double acting rod, this isn't necessary. |
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| Author: | LarryH [ Fri Feb 10, 2006 2:49 pm ] |
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[QUOTE=Daniel M] Larry; When I'm getting ready to level the fingerboard, I tighten the truss rod enough that the neck takes on a visible back bow, then I level & arch the board. This pre-stresses the neck so that if the neck takes on a back bow when it is fretted, there is enough built in "spring", to allow it to straighten out again when the rod is eased off. As mentioned, if you use a double acting rod, this isn't necessary.[/QUOTE] Thanks VERY much Daniel for the reply. I just wasn't gettin the picture. Larry |
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