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kestrel
Jan-20-2008, 10:22am
I have an old Ibanez classical guitar that Iíve no desire to play, for numerous reasons. Iím firmly entrenched in mandolin and mandolin family instruments. For me, the thing is virtually unplayable. Itís 2-1/6Ē wide, at the nut, making it feel like the width of a football field, compared to even my octave mandolin and tenor banjo. I have arthritis in my left wrist, that makes it impossible for me to reach the sixth-string, and the fifth is an uncomfortable struggle on this wide neck. The neck is very thin, with no truss rod, is straight, but angles way too much upward (Itís a bit high at the first fret, and 3/16Ē high at the twelfth.).

I donít believe the instrument is of any great value. Iíve checked with some of the guitar forums, and no one has even been able to tell me that the model and S/N ever even existed. Iíve owned it for nearly thirty-years. The thing I do believe is that it has a really nice solid box Ė very pretty mahogany back and sides, and a really fine, tight-grained cedar (I think.) soundboard. It is bound, top and bottom, and has a very nice inlaid rosette. The thing has a fine, full sound.

Iím considering building a new neck for this instrument, and converting it into a tenor guitar Ė or mandocello. I would imagine that Iím going to have to add to/change the bracing pattern, and probably build a new head block. Since I guess Iím going to need to remove the bridge, I think Iíd like to go with a tailpiece and a floating bridge.

I would really appreciate some comments and suggestions regarding the feasibility of such a conversion, and any suggestions you might have as to bracing pattern. Would you recommend structural alterations to allow for steel strings, or would I be better off going with nylon. This will be for playing for my own pleasure, and occasional jamming with a guitar-playing friend, not for gigging or big-time jamming. I play mostly Irish Traditional and Oldtime, and am starting to delve into Blues and a little bit of Jazz. I finished my first scratch-built oval-hole mando, in November, and this would be more or less a learning project, with the hope of making an instrument which has seen no use for thirty-years into something I could have some fun playing.

Thanks in advance for advice/suggestions.

Gene

Bill Snyder
Jan-20-2008, 10:49am
I would think it would implode. The fan bracing on classical guitars is not intended to hold up to much tension. While the braces are many they are light.

kestrel
Jan-20-2008, 11:30am
Uh-h-h-h-h-h...

"I would imagine that Iím going to have to add to/change the bracing pattern, and probably build a new head block."

"and any suggestions you might have as to bracing pattern. Would you recommend structural alterations to allow for steel strings, or would I be better off going with nylon."

Gene http://www.mandolincafe.net/iB_html/non-cgi/emoticons/biggrin.gif

markishandsome
Jan-20-2008, 11:58am
If it has a Spanish heel like many classical guitars, you'll have to saw the neck off and bolt the new one on. Add to that removing the bound top and completely re-bracing it... probably easier to make a new top, or a scratch build. I think the whole point of these conversions is that it's supposed to be EASIER than making a new instrument from scratch.

kestrel
Jan-20-2008, 3:52pm
Actually, I suppose my primary reason for this, would be to use it as more of a learning experience, and practice repair work. I'm not really in the market for a tenor, or 'cello, but I doubt that there would be any value in selling or trading this instrument, and it's just hanging around gathering dust. I think it would be a fun project, but I would like to end up with a playable instrument, that I could enjoy.

So-o-o, let me rephrase my initial post: I AM going to convert a classical guitar into a tenor guitar, a mandocello, or I am going to take it apart and recycle the top and back to build a mandolin or mandola. I would prefer to do the former.

I am requesting some input regarding the best way to go about it - not reasons why I shouldn't do it, unless someone tells me it is a valuable instrument. I'm sure that with diligent searching, I'll be able to find the information I need. I just thought that this community might offer some constructive suggestions.

Thanks,

Gene

Jim Garber
Jan-20-2008, 5:25pm
I would really appreciate some comments and suggestions regarding the feasibility of such a conversion
I know you rephrased your question later, but considering your OP, you can't get annoyed at folks for discussing the feasibility, right?

Anyway, I think that there were valid points made. Frankly I like your second possibility much better: using the top and back wood to make an mandolin or mandola.

Red Henry
Jan-20-2008, 6:13pm
I suspect that a tenor guitar or octave mandolin project would work better on that testbed than a mandocello. I believe that a mandocello normally puts a lot more string-tension on the instrument than even a steel-string guitar would have, so putting that amount of strain on that guitar might not last.

Red

Bill Snyder
Jan-20-2008, 8:36pm
Gene you are correct that there are some of the fine luthiers here that can offer some advice. Another good resource would be the Musical Instrument Makers Forum. (http://www.mimf.com) Like this forum most of them are friendly people willing to share their knowledge in order to further the craft and art of instrument building.

markishandsome
Jan-20-2008, 8:38pm
How about a nylon strng tenor guitar? Then you wouldn't need to redo the top bracing or bridge. Depending on your neck joint, you may not even need to remove the top, which could get ugly. If you really want the challenge and experience of retopping a guitar, then more power to you, but why waste so much time on an instrument you may not end up playing any more than you do in its current state? If you make a new neck you'd have some flexibility in the scale length and could go GDAE or CGDA. If you stuck with nylon you may be able to modify the existing neck rather than making a new one. Again, you're welcome to dump more effort into the thing if you want, but you could probably pick up more practical repair experience doing refrets etc on your own instruments or yardsale specials AND get a playable instrument from your guitar in the time it would take you to make a silk purse out of it.

allenhopkins
Jan-20-2008, 11:53pm
Concur with the general drift of the responses. #Classical guitars are very lightly built compared to steel-strings -- thinner tops, lighter bracing. #Once you put the new 8-string neck on, which won't be all that easy to do since you probably don't have a dovetail joint to steam apart --

AND you build and install a new neck block and end block, since I imagine you're planning a tailpiece/floating bridge set-up --

THEN you'll probably have to re-brace the top to take the tension of eight steel strings. #Most of the mandocello or octave mandolin conversions that have been proposed, have been of inexpensive arch-top guitars, which are braced for steel strings, and already have the tailpiece/floating bridge configuration. #

I like M-handsome's suggestion of the nylon strung tenor. #You reduce rather than increase tension, you can use the existing bridge configuration, you don't need to make a new end block. #Basically you'll be making and installing a new neck, which is no trivial task, but you can be relatively confident the resulting hybrid won't tear itself apart under string tension.

kestrel
Jan-21-2008, 8:34am
"I like M-handsome's suggestion of the nylon strung tenor. You reduce rather than increase tension, you can use the existing bridge configuration, you don't need to make a new end block. Basically you'll be making and installing a new neck, which is no trivial task, but you can be relatively confident the resulting hybrid won't tear itself apart under string tension."

Yep, I definitely agree with you both, and I do like the idea of a nylon strung tenor guitar. Like I said, it will be just for my own messing around. I don't need a bunch of power, just to sit around and noodle by myself, and I think my bum wrist will also be more agreeable to a narrow neck and nylon strings.

I am going to have to do some engineering to attach a new neck, though. It appears that the existing neck was originally mis-set. It's straight, there is no separation between the neck and body, and there is no evident slippage between the head-block and the top or bottom, but there is an upward angle from the join to the peghead. The fingerboard rises above the plane of the soundboard - which is also very straight and flat. Am I making any sense, there?


I'm thinking - saw off the old neck at the body join, then cut a simple straight mortise into the head block? That way, I wouldn't need to remove either the top or back. Then, adjust the new neck angle in relation to the plane of the top, and the existing bridge? I think I'll work in some sort of inlay, or pick guard design to cover the difference between the narrower neck, and the old wide one, on the soundboard.

I would think that, by staying with nylon strings. and reducing the number to only four, a simple mortise and tenon would be a more than adequate attachment? Would I be best in maintaining the same scale length, or is some other scale considered to be more optimal for a tenor? Would a truss rod be advantageous, or would a piece of carbon fiber be adequate in a mahogany neck?

I know I've got a lot of questions. The woodworking skills and the equipment, I have. It's the instrument dynamics that I'm just now learning, and I've found no better place to get good advice, than here.

Thanks,

Gene

Bill Snyder
Jan-21-2008, 8:59am
While there is no hard and fast rule for a tenor scale 23" seems to be the most common. Classicals are frequently greater than 25 1/2". If you are building a new neck you can shorten it up to 23".

delsbrother
Jan-21-2008, 4:41pm
Wouldn't it just be easier to give the guitar to someone who wants a classical guitar and practice on something more suitable? It just seems like you're intent on destroying the guitar for no good reason.

There are nylon string tenor guitars in Brazil, (violao tenor) but I don't know how they're tuned or used. I would love one. But I wouldn't think to modify a 6 string classical to get one. YMMV.

kestrel
Jan-22-2008, 1:18pm
"I am going to have to do some engineering to attach a new neck, though. It appears that the existing neck was originally mis-set. It's straight, there is no separation between the neck and body, and there is no evident slippage between the head-block and the top or bottom, but there is an upward angle from the join to the peghead. The fingerboard rises above the plane of the soundboard - which is also very straight and flat."

I've thought about doing just that, but I've had a few guitar players claim that the instrument is virtually unplayable, due the the way the neck rises so badly. It would need to have the neck re-set, to make it playable, and if I'm going to go to that trouble, I might as well make it into something I can enjoy.

Gene

delsbrother
Jan-22-2008, 4:59pm
The more correct logic would be "if I'm going through that trouble, I might as well build a new guitar."

Also realize if you go with a tenor scale (but leave the bridge where it is) you will have a short, thin neck sticking out of a big classical body (i.e. fewer than 12 frets clear).

Look up martinjonas' neck "build up" repair to his mandolinetto as another option. You might be able to plane/remove the fingerboard and then replace it with a shimmed one at a better angle. While you're doing that you can decide whether to keep it as a six string or thin the neck for four.

Bill Snyder
Jan-22-2008, 6:17pm
Gene post pictures when you are done. If your guitar currently joins at the 12th fret (most classicals do) and it has about a 25.87 scale length now and you put a 23" scale neck on it without moving the bridge the neck will join between the 9th and 10th frets. I suppose you could just have a really long scaled tenor(?) and leave the scale length like it is. You might end up tuning it a bit differently but keep it in fifths.
You will figure out what you want to do and how to do it. You can always come back here are go to the mimf and ask if you need to.

kestrel
Jan-24-2008, 8:08am
"Look up martinjonas' neck "build up" repair to his mandolinetto as another option. You might be able to plane/remove the fingerboard and then replace it with a shimmed one at a better angle. While you're doing that you can decide whether to keep it as a six string or thin the neck for four."

Tried a search, but it just brought me back to this thread. I like this idea, though. I'd still need to narrow the neck. It's so wide that I cant make my arthritic wrist bend to reach the bass strings.


"You might end up tuning it a bit differently but keep it in fifths."

Tuning it in fifths was a primary consideration - so I wouldn't need to re-learn. Lazy, I guess. I'm now thinking I may try the build-up; narrowing the neck, but keeping it a six string; put in a carbon fiber reinforcer; stay with nylon strings, and just make my old mind learn guitar fingerings. They say that new challenges help keep us old folks from getting Alzheimerís.

I've got some more pressing projects underway in the shop, right now, so it will be a while. I'll yell if I run into difficulties, and will post pics when I'm finished.

Thanks a lot for the suggestions.

Gene

Bill Snyder
Jan-24-2008, 9:12am
Gene I believe THIS (http://www.mandolincafe.net/cgi-bin/ikonboard.cgi?act=ST;f=15;t=47061;st=0) is the thread delsbrother was refering to.