Guitars by Jake Posted April 22, 2009 Report Share Posted April 22, 2009 (edited) I am buiding a four string bass, and after gluing up the fretboard, I ended up with a bad back bow. I am using a double acting truss rod, but I pretty much max it out trying to correct it. Also, I dont want this bass going out to the world and suddenly falling apart due to the fact that it is under stress from the truss rod. I have made many necks this way, and never had anything this bad happen. Should I steam off the fret board? And if so, what is the best technique/tools. I have seen it done, but Im kinda nervous about trying it myself. Edited April 22, 2009 by Guitars by Jake Quote Link to comment Share on other sites More sharing options...
aggravated_alien Posted April 22, 2009 Report Share Posted April 22, 2009 (edited) I am buiding a four string bass, and after gluing up the fretboard, I ended up with a bad back bow. I am using a double acting truss rod, but I pretty much max it out trying to correct it. Also, I dont want this bass going out to the world and suddenly falling apart due to the fact that it is under stress from the truss rod. I have made many necks this way, and never had anything this bad happen. Should I steam off the fret board? And if so, what is the best technique/tools. I have seen it done, but Im kinda nervous about trying it myself. I see you haven't put the frets in yet. I would just level the board with a leveling block. Edited April 22, 2009 by aggravated_alien Quote Link to comment Share on other sites More sharing options...
Guitars by Jake Posted April 22, 2009 Author Report Share Posted April 22, 2009 I am buiding a four string bass, and after gluing up the fretboard, I ended up with a bad back bow. I am using a double acting truss rod, but I pretty much max it out trying to correct it. Also, I dont want this bass going out to the world and suddenly falling apart due to the fact that it is under stress from the truss rod. I have made many necks this way, and never had anything this bad happen. Should I steam off the fret board? And if so, what is the best technique/tools. I have seen it done, but Im kinda nervous about trying it myself. I see you haven't put the frets in yet. I would just level the board with a leveling block. I have thought about that, but I have some rather nice block inlays in there. The fretboard is probably thick enough, but I am not looking forward to sanding through, and replacing inlays. I am considering taking it apart, and salvaging the fretboard and truss rod, but making a new neck blank and starting fresh. Quote Link to comment Share on other sites More sharing options...
aggravated_alien Posted April 22, 2009 Report Share Posted April 22, 2009 I am buiding a four string bass, and after gluing up the fretboard, I ended up with a bad back bow. I am using a double acting truss rod, but I pretty much max it out trying to correct it. Also, I dont want this bass going out to the world and suddenly falling apart due to the fact that it is under stress from the truss rod. I have made many necks this way, and never had anything this bad happen. Should I steam off the fret board? And if so, what is the best technique/tools. I have seen it done, but Im kinda nervous about trying it myself. I see you haven't put the frets in yet. I would just level the board with a leveling block. I have thought about that, but I have some rather nice block inlays in there. The fretboard is probably thick enough, but I am not looking forward to sanding through, and replacing inlays. I am considering taking it apart, and salvaging the fretboard and truss rod, but making a new neck blank and starting fresh. What is your relief on the neek. Have you measured it. Quote Link to comment Share on other sites More sharing options...
Guitars by Jake Posted April 22, 2009 Author Report Share Posted April 22, 2009 The neck is in mid-build. As far as relief goes, If I max out the truss rod, and check with straightedge, I still have a bit of a back bow. sort of a hump in the middle section. Quote Link to comment Share on other sites More sharing options...
Keegan Posted April 22, 2009 Report Share Posted April 22, 2009 What kind of glue did you use? Titebond? I've heard of this happening with water-based glues because they cause the wood to expand. Quote Link to comment Share on other sites More sharing options...
Jaden Posted April 22, 2009 Report Share Posted April 22, 2009 ive had this happen once to me recently, its only happened once and I couldnt get to the bottom of why, I make all my necks the same and it was one of a batch to a customer, it backbowed and others didnt. I steamed off the board and used the board again, threw the neck on the fire. Quote Link to comment Share on other sites More sharing options...
Guitars by Jake Posted April 22, 2009 Author Report Share Posted April 22, 2009 Thanks everybody. Yeah, Ive never come across nothing like this, and I have built quite a few necks using the exact same method. I guess I either missed something along the way, or the wood just had a bad attitude. Jaden, I think thats exactly whats going to happen. I am considering heatlamps however. Luckily I have just enough wood left over for the headstock veneer! Quote Link to comment Share on other sites More sharing options...
NotYou Posted April 23, 2009 Report Share Posted April 23, 2009 (edited) Before you do anything drastic, let it sit for a few days. I've heard from some well respected builders that they come across this exact issue all the time and it corrects itself in a about a week, after the wood dries. That doesn't seem to make sense, but I can't argue with them if it works. Edited April 23, 2009 by NotYou Quote Link to comment Share on other sites More sharing options...
Kenny Posted April 23, 2009 Report Share Posted April 23, 2009 this happened to one of my necks, but the effect was multiplied by the fact it didn't glue correctly in the middle either; let it sit for a while, if it doesn't fix itself rip it off, save the rod and make a show out of it Kenny Quote Link to comment Share on other sites More sharing options...
SJE-Guitars Posted April 23, 2009 Report Share Posted April 23, 2009 Steaming off fret boards with a steam iron is a doddle . . . just follow the tutorial on the project guitar home page with a razor and a sharpened scraper and once you get used to doing it you'll be getting a board off in about 20 minutes. Quote Link to comment Share on other sites More sharing options...
Rista Posted April 23, 2009 Report Share Posted April 23, 2009 What kind of glue did you use? Titebond? I've heard of this happening with water-based glues because they cause the wood to expand. Yep, this happened on my first build. I used Titebond to glue on the fretboard and it did move although nowhere near as much as in those pictures. I saw people recommending epoxy for attaching the board to the neck because it doesn't introduce any moisture so I tried that on my latest build. It worked great and I'll definitely be using epoxy for fretboards from now on. Quote Link to comment Share on other sites More sharing options...
Vinny Posted April 23, 2009 Report Share Posted April 23, 2009 Fellas, use the add reply button at the top or bottom of the page. When you hit reply inside the thread box you're dragging up the pictures again and again. Thanks, Vinny Quote Link to comment Share on other sites More sharing options...
SJE-Guitars Posted May 9, 2009 Report Share Posted May 9, 2009 I think there must be something in the air for this problem! I had a neck do this last week - however I discovered once I removed the fretboard the neck actually straightened up alone. I can only assume then when I clamped the fretboard in place during glueing I somehow bowed the neck so when the glue dried it held it in the bowed position. I steamed off the fretboard left them settle over night and hey presto all was straight again, cleaned up the old glue and reattached fretboard and it's perfectly straight. Quote Link to comment Share on other sites More sharing options...
Woodenspoke Posted May 9, 2009 Report Share Posted May 9, 2009 You could try heating up the fingerboard and clamping neck until its straight again. I would suspect it is a clamping issue rather than glue moisture. You can use a shop lamp to heat up the board to about 250, use a surface thermometer. may save you lots of extra work and will give you some neck straightening repair experience. Couldnt hurt to try. Quote Link to comment Share on other sites More sharing options...
Guitars by Jake Posted May 9, 2009 Author Report Share Posted May 9, 2009 I managed to get the fret board off the neck using a heat lamp, cost me all of 5 bucks. I decided to replace the neck however, just to be on the safe side, as this was for a client. I too believe it was just a clamping error. This time around, I glued the fretboard on before shaping the neck, and it came out perfect! Only really lost a couple of days, and that was only because of glue dry time. (normally I like to shape the neck a little first, but due to this experience, I think I have a new method.) Quote Link to comment Share on other sites More sharing options...
supplebanana Posted May 27, 2009 Report Share Posted May 27, 2009 2 things spring to mind - (i know its too late now coz you've already pulled the board - but for future ref.) 1) will the neck not pull straight under string tension? & 2) if not - what about using Dan Erlewine's method for straightening a back bowed neck? The video I saw of him doing this was on a guitar that had a back bow just as bad as that & he got it straight. also - when I clamp a f/b i start in the middle & work to the ends coz if you start by clamping each end 1st you can introduce a bow as you clamp the rest (kind o'like a bi-metal strip action) sb Quote Link to comment Share on other sites More sharing options...
SJE-Guitars Posted May 28, 2009 Report Share Posted May 28, 2009 2 things spring to mind - (i know its too late now coz you've already pulled the board - but for future ref.) 1) will the neck not pull straight under string tension? & 2) if not - what about using Dan Erlewine's method for straightening a back bowed neck? The video I saw of him doing this was on a guitar that had a back bow just as bad as that & he got it straight. also - when I clamp a f/b i start in the middle & work to the ends coz if you start by clamping each end 1st you can introduce a bow as you clamp the rest (kind o'like a bi-metal strip action) sb 1) Maybe - maybe not. But if it's a new neck you still need beable to check the fret levels and the only way you could it would be when it's strung up . . which ain't easy . . . or purchase one of those darn expensive jigs that Stumac sell. 2) I've not seen this method . . is there a video? The thing is however that the problem on this thread was a new neck which seems to have been clamped when attaching the fretboard to have the back bow - rather than the wood altering over time. So the neck was never straight to begin with. The one I did was exactly the same - I know I tried a different method of clamping and most likely artificially bowed the neck - so when the glue on the fretboard set it held the bow in the neck. Just removing the fretboard and reattaching it fixed the problem. Quote Link to comment Share on other sites More sharing options...
Woodenspoke Posted May 28, 2009 Report Share Posted May 28, 2009 2 things spring to mind - (i know its too late now coz you've already pulled the board - but for future ref.) 1) will the neck not pull straight under string tension? & 2) if not - what about using Dan Erlewine's method for straightening a back bowed neck? The video I saw of him doing this was on a guitar that had a back bow just as bad as that & he got it straight. also - when I clamp a f/b i start in the middle & work to the ends coz if you start by clamping each end 1st you can introduce a bow as you clamp the rest (kind o'like a bi-metal strip action) sb I think what SB is trying to say and what I tried to say is if you heat up the fretboard and put a bit of a reverse bow in the neck using clamps the heat will have softened up the glue enough to allow you to adjust the neck back to where it should be. Since it is a clients guitar then your fears of a problem piece of wood were justified. Quote Link to comment Share on other sites More sharing options...
Guitars by Jake Posted May 29, 2009 Author Report Share Posted May 29, 2009 Funny I see this post up. Client just walked out with the bass 5 minutes ago! The new neck worked out perfect, and I think I even changed my method on future builds, because of this experience. (what doesnt kill you only makes you stronger, right!) Honestly the only thing that bugs me now is those block inlays. Not that they were jumping off of the fretboard or anything, but I added some # 10 super glue around the edges, hoping it would soak up a little, just in case. (very happy client by the way.) Maybe I will put up some pics soon. Quote Link to comment Share on other sites More sharing options...
supplebanana Posted May 29, 2009 Report Share Posted May 29, 2009 Jake - PM fer ya sb Quote Link to comment Share on other sites More sharing options...
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