Wednesday, July 10, 2013

Oooops. I over-thinned my back plates!

I live all the way over here in Ireland. I'm in the process of building the steel string guitar from your book and have just noticed that I have planed the back too thin (0.085"- the dimension as the sides)
I am using Amazaque for the back and wondering am I wasting my time completing the build with this back and just bite the bullet and purchase a new set of plates. I don't need my first build to be perfect but still don't want to be disappointed when the build is finished due to this error of mine

Hope you have the time to reply to this. I just want to say that your book is brilliant and has given me a new addiction and already planning future build. 


I seem to be getting a lot of mail from Ireland lately!

I don't know if you've bent or assembled the sides yet.  Or what size the guitar is to be. Or how coarse the surface grit pattern is, that you'll have to remove with sanding. Also, I've never faced the precise dilemma that you're facing. So I can't vouch for the quality of my advice. But i can think of some potential disadvantages to making a guitar with a back that is no thicker than .085".

1- If it's the large guitar precisely like the one in my book that you're building, the back is likely to sag somewhat between the back braces and look somewhat lumpy and peculiar.

2- If it's a very dense wood, it is likely to crack easily, like a thin sheet of glass--either spontaneously if you let it dry out, or after a gentle impact.

3- Acoustically, the effect of thin plates on a large guitar is to drop the resonant frequency of the sound box, likely lending the guitar a somewhat tubby sound.

If I was given a set with a thin back plate to make a guitar from it, I would choose to make a 13-14-inch parlor guitar. A back of that thickness would not be disproportionate. But I don't know how far along the rest of your project is, so I don't know if that's very useful advice. Sorry.

Will a 3-piece neck solve my action instability problems?

I live not far from you in New England... therefore.. yes I am experiencing neck warping and bowing issues. I have sent the guitar to Fender, who says they have kept the original Guild Custom Shop, and they bleeped me royally. They agreed that the neck was a warranty issue, but claimed that because the TOP had a little wear on it they wouldn't do the warranty work unless they replaced the top at a cost of $500.00 to me. I fought and fought, but they held fast, and because I love the guitar, I agreed to let them do it. They did and rebuilt the neck, replaced the top and bridge and saddle. I got it back and 3 weeks later had to send it back to Nashville for a neck reset. Horrible craftsmanship. Anyway they fixed it and I played it for 6 months and here I am again with the neck problem. I have made three custom saddles varying in height to be able to adjust the action, and it seems to work okay. 
     What I am looking for from you is, (I am a carpenter by trade), [is a solution] to remove the neck and fret board, take 1/2" out of the middle of the neck, replace the cutout piece with a piece of blond maple, lose the truss rod, and laminate the three pieces together, mount the fret board and remount the neck to the soundbox. In my 35 years experience with wood, I feel there is a 70% chance the problem will be permanently resolved. And if I have to go back to using the different saddles then so be it, but I would like to try my idea. Can you hint to me in yes or no fashion if my idea of a three piece laminated neck may solve this issue?


Can I hint whether inserting a 1/2 inch maple spline in the neck--in replacement of a steel truss rod--is going to resolve "neck warping and bowing issues"? Well, to have an opinion I would have to know for certain if your action-height instability problems are in fact the result of a neck that is insufficiently stiff, and whether removing the steel truss rod and replacing it with a maple spline would in fact make it more stiff.

Well, maple is stiffer than mahogany but not as stiff as steel. Mahogany is only "moderately" stiff while maple is of "high" stiffness. On the other hand, mahogany is far more dimensionally stable than maple (as regards to changes in environmental humidity fluctuations). Your plan to replace steel with maple to make the neck both stiffer and more stable seems a bit iffy. I don't know how massive or how flexible your steel truss rod is--I don't keep track of the nature of every truss rod on every guitar model in the industry. But I've seen some truss rods that are enormously stiff while I've seen others that seem as stiff as a limp noodle. So I can't opine in that regard without knowing what's being replaced.

But consider this: your problems with action-height instability can happen even if the neck itself remains perfectly straight and un-bowed. For example, a perfectly straight neck can rotate upwards at the heel. That is, the entire neck AND headblock can rotate upwards in the soundbox--with everything stretching around it. The soundboard itself can rise and drop in a variable climate, independent of what the rest of the guitar is doing. The entire guitar from tip to tail can stretch like a long bow--every element between tip and tail stretching just a tiny bit, to add up to a noticeable action-height change. So what is the likelihood of a 1/2-inch maple spline inserted laboriously into your neck, in order to resolve action-height instability? Not very high, I would guess.

What is indeed seriously troubling is that Fender convinced you to replace the entire top to resolve action instability problems because it "had a little wear" on it--at your expense. Either you're not telling me the entire story, or they really have taken you for an innocent rube on this. If they knew that your action instability was the result of your top collapsing--this would warrant a new top--it is they who should have picked up the tab. They may not have told you the real reason WHY the top needed replacement (a "little wear" is ridiculous) but if they noted serious distortion on the soundboard they should have owned up to the situation--instead of telling you that a little wear had to be resolved before they could solve your action problem. Very troubling. Shame on them.