Mickguard Posted October 16, 2008 Report Posted October 16, 2008 Some time ago I picked up an old Norman B30 (1970s Canadian dreadnought, spruce top, laminated maple back and sides, bolt-on maple neck) at a yard sale for 10 euros. There are a couple of questions buried in the description below, so bear with me... The guitar had massive issues -- much of which were caused by someone's attempt to "fix" the guitar before. Which involved flattening all of the frets way beyond the playable range. Lots of other mistakes were made. They'd stripped the bolt on the truss rod too, so that was jammed and unusable. The biggest problem with the guitar though was that the neck was warped -- at first, I thought it was twisted, but that turned out to be mostly because of a bad shim job under the neck (and it's the table that's warped). But the main problem with the neck was that it had a weird bow to it -- you could see clearly a dip from the the nut end of the fretboard to about the fifth fret. I'm assuming the thing was leaned up against a wall (probably in a closet) supported by its headstock for many years.... But I need a beater guitar to bring around, and I have a case that fits this one (my other guitar is a too-nice-to-leave-the-house Takamine jumbo and I don't have a case for it) . So first I defretted the neck. Then I used a dremel to cut slots for a flathead screwdriver in the truss rod bolt. Then I clamped the fretboard to a square steel beam. That flattened the neck enough to allow me to free up the truss rod. I left the neck clamped like that for a couple of days. I then cleaned up the fretslots a bit, adding indents. And I polished the fretboard with micromesh pads -- I really like a mirrored fretboard. The dip in the neck was still there, but the clamping and the workable truss rod did help a bit -- I had planned on using normal acoustic fretwire, but I happened to have enough jumbo wire on hand. Since the tang was wider than the original frets, the idea was that the compression of the new frets would lift the dip in the neck (picked this up from a recent discussion about that elsewhere in the forum). And that worked, between that and having a working truss rod again, the neck is much straighter than before...although it's still not possible to get it perfectly flat. In the meantime, I cut a new bone saddle for the guitar, replaced the tuners, added a new nut. I spent the last week or so working on the adjustment of all the different components -- in the end, I developed a new shim for the neck that lifts the bass side (by about 0.5 millimeters) leaving the treble side a bit lower. I must have tuned and detuned the guitar a couple dozen times, went through two sets of (used) strings in the process. The shim is necessary because the top of the guitar has a slight warp in it --raising the entire bridge, so that there wouldn't be enough downward tension on the bridge saddle if I kept the neck flat and adjusted things at the saddle. But I went a little too far with the new saddle (it's the first time I tried making one), it doesn't follow the radius exactly-- I'll have to cut a new one eventually. I'm thinking I could better have left the bridge taller and added notches for the individual strings? Why don't I see other acoustics with saddles like that? ... Anyway, the issue with the bridge is mostly because of the issues with the neck -- since I haven't gotten rid of that dip completely, I've had to achieve a compromise with the other components of the action. This means that the action is within a fraction of where I like it, but that allows a bit of fret buzz --mostly on the G string -- which forces me to use a lighter hand when I play...not a bad thing, but still. One thought I had was to try to use heat to move the neck the rest of the way flat -- can anyone give me thoughts on that? I'm thinking I can clamp the fretboard to a straight block of wood, and heat the back of the neck in the area of the dip. That should encourage the wood there to flatten out again, right? As it is, with medium strings (13- 54) on there, and the working truss rod, I've managed to make a very playable guitar out of this old thing. And surprise, surprise, it's even intonated (it was far from that before). Just a bit more tweaking will make it an excellent player --it's a maple body, so the sound is never going to be that great). But I like it so much, I'm considering selling off the Takamine (and start saving up for a higher-end spruce/rosewood guitar). I'm actually kind of proud of the job I did, and being able to put to work all the things I've learned from hanging out in this forum. Now I have to clean up the rest of the residue left from the glue from the old pickguard (which had warped and lifted off). Quote
truckjohn Posted December 13, 2008 Report Posted December 13, 2008 Some time ago I picked up an old Norman B30 (1970s Canadian dreadnought, spruce top, laminated maple back and sides, bolt-on maple neck) at a yard sale for 10 euros. There are a couple of questions buried in the description below, so bear with me... The guitar had massive issues -- much of which were caused by someone's attempt to "fix" the guitar before. Which involved flattening all of the frets way beyond the playable range. Lots of other mistakes were made. They'd stripped the bolt on the truss rod too, so that was jammed and unusable. The biggest problem with the guitar though was that the neck was warped -- at first, I thought it was twisted, but that turned out to be mostly because of a bad shim job under the neck (and it's the table that's warped). But the main problem with the neck was that it had a weird bow to it -- you could see clearly a dip from the the nut end of the fretboard to about the fifth fret. I'm assuming the thing was leaned up against a wall (probably in a closet) supported by its headstock for many years.... But I need a beater guitar to bring around, and I have a case that fits this one (my other guitar is a too-nice-to-leave-the-house Takamine jumbo and I don't have a case for it) . So first I defretted the neck. Then I used a dremel to cut slots for a flathead screwdriver in the truss rod bolt. Then I clamped the fretboard to a square steel beam. That flattened the neck enough to allow me to free up the truss rod. I left the neck clamped like that for a couple of days. I then cleaned up the fretslots a bit, adding indents. And I polished the fretboard with micromesh pads -- I really like a mirrored fretboard. The dip in the neck was still there, but the clamping and the workable truss rod did help a bit -- I had planned on using normal acoustic fretwire, but I happened to have enough jumbo wire on hand. Since the tang was wider than the original frets, the idea was that the compression of the new frets would lift the dip in the neck (picked this up from a recent discussion about that elsewhere in the forum). And that worked, between that and having a working truss rod again, the neck is much straighter than before...although it's still not possible to get it perfectly flat. In the meantime, I cut a new bone saddle for the guitar, replaced the tuners, added a new nut. I spent the last week or so working on the adjustment of all the different components -- in the end, I developed a new shim for the neck that lifts the bass side (by about 0.5 millimeters) leaving the treble side a bit lower. I must have tuned and detuned the guitar a couple dozen times, went through two sets of (used) strings in the process. The shim is necessary because the top of the guitar has a slight warp in it --raising the entire bridge, so that there wouldn't be enough downward tension on the bridge saddle if I kept the neck flat and adjusted things at the saddle. But I went a little too far with the new saddle (it's the first time I tried making one), it doesn't follow the radius exactly-- I'll have to cut a new one eventually. I'm thinking I could better have left the bridge taller and added notches for the individual strings? Why don't I see other acoustics with saddles like that? ... Anyway, the issue with the bridge is mostly because of the issues with the neck -- since I haven't gotten rid of that dip completely, I've had to achieve a compromise with the other components of the action. This means that the action is within a fraction of where I like it, but that allows a bit of fret buzz --mostly on the G string -- which forces me to use a lighter hand when I play...not a bad thing, but still. One thought I had was to try to use heat to move the neck the rest of the way flat -- can anyone give me thoughts on that? I'm thinking I can clamp the fretboard to a straight block of wood, and heat the back of the neck in the area of the dip. That should encourage the wood there to flatten out again, right? As it is, with medium strings (13- 54) on there, and the working truss rod, I've managed to make a very playable guitar out of this old thing. And surprise, surprise, it's even intonated (it was far from that before). Just a bit more tweaking will make it an excellent player --it's a maple body, so the sound is never going to be that great). But I like it so much, I'm considering selling off the Takamine (and start saving up for a higher-end spruce/rosewood guitar). I'm actually kind of proud of the job I did, and being able to put to work all the things I've learned from hanging out in this forum. Now I have to clean up the rest of the residue left from the glue from the old pickguard (which had warped and lifted off). I think my #1 earliest lesson so far has been that Playability is by far #1 consideration for a Guitar. A smooth, easy, comfortable neck, properly levelled and crowned frets, and proper action make up for a whole lot of "Boxy" Cheap Chinese evil. On the string setup... Basically, the relationship between the strings heights makes a significant difference in the sound. If one string is too high, it makes the guitar sound weird and bad. If the profile of "High" to "Low" is off -- like one of the treble strings is taller than one of the bass strings -- it throws the whole sound out of whack. I got a ton of good information over at Bryan Kimsey's website. My short answer when working on a "Beater" is to spend the $6.00 and get yourself a set of Automotive feeler gages to do string height setup at the 1st and 12th frets. A ruler is just not accurate enough. http://www.bryankimsey.com/setup/index.htm This is not the only way, but it is probably the only place on the web that gives numbers for each string height rather than "Match the fingerboard radius then sand it a little lower on the Treble side" -- That way works too.... and literally millions of guitars are shipped to happy customers like that. My trouble was "How good are you at hand sanding the profile?" Good luck John Quote
soapbarstrat Posted December 13, 2008 Report Posted December 13, 2008 (edited) One thought I had was to try to use heat to move the neck the rest of the way flat -- can anyone give me thoughts on that? I'm thinking I can clamp the fretboard to a straight block of wood, and heat the back of the neck in the area of the dip. That should encourage the wood there to flatten out again, right? Most of the time the heating method is a waste of time. But to even do that method properly, you need to have a surface thermometer or two laying on the neck to keep from damaging the neck, because the amount of heat you will need will be right on the border of causing damage to the neck. Plus, the neck would need to be held in a back-bow while doing it, because you need to over bend a little in the direction you're trying to get the neck to go into, because it's going to still want to spring back to how it had been, so you hope that by over-doing it, it will end up close to where you want it. *And* usually the heat method is chosen because a neck doesn't have an adjustable truss-rod or is valuable enough that you want to try to avoid removing fret-board wood as much as possible. You should measure that dip with an SE and gauges. If it's not extreme, it can be leveled out. If you do level the board, maybe try a Martin repair department trick, where you have support under the headstock and about 12 pounds of weight on the body to simulate string tension (I don't know how they came up with 12 pounds, but I just take their word for it, since I never experimented with how much downward weight one would place on a body to simulate string tension) You probably already did this, but, if you can take the t-rod adjusting nut off, do that, clean threads with a pipe cleaner, and a little thick lube on the threads and the bearing face of the nut. Put the nut back on, but leave it loose. Clamp or pull neck into a generous backbow, hold it there and tighten the t-rod nut as much as possible (yes, a chance you'll bust the rod, just quit when it feels like any more turning and something is going to bust) Edited December 13, 2008 by soapbarstrat Quote
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