Issues with converted mandocello

[Michael T]

Hey! I've enjoyed the Cafe for a long time, but am just posting for the first time now that I need your input on a question I have. :)

About two years ago, I bought a mandocello that had recently been converted from an old 1950s archtop Kay guitar. I was hoping to try out a mandocello for cheap, and I had seen several really nice archtop conversions here before I bought this one. I found out that I really loved the sound. The problem is, this thing is a bear to play.


Here are the problems that I have with it. The neck has gotten really bowed, so that even in first position, the action is really high. The instrument doesn't have a truss rod, which I think has contributed to the bow getting even worse over time. The string height at the 12th fret is almost 1/4", and it is already 1/8" by the fourth fret. It is currently strung with 59-44-34-18 gauge strings, which it looks like are already a pretty light compared to the D'Adderio mandocello strings, for example. The person who did the conversion also thought that the guitar had a neck reset at some point, so I don't know if this is contributing to the problem as well.



The other problem that I frequently have with it is that the string pairs split around my finger when I am fretting. I think a new nut with better string spacing might help with this, but I haven't played other mandocellos to know if this is a common problem.


With these issues, do you think this mandocello could be made playable? What repairs would it need, and would it be worth the cost considering it was an inexpensive guitar to begin with?

Thanks!
Just for fun, I thought I'd throw in a sound clip from when I first got the mandocello and was playing it more. This is me fumbling through some of the Bach Cello Suite in G. :)
mandocello sample.mp3.

[stevojack665]

Welcome to the Cafe!
I used to have a Harmony archtop that was converted to mandocello. Good, but not great.
Here is what I would recommend:
Remove one string from each of the C and G courses. These guitars were never well made, and certainly were not made to withstand that much extra tension.
It will also no longer be a problem of fingers slipping between the strings, as you'll only have one on each of those courses.
That will help some with the neck.
Then see if there is any way to get the bridge lowered, without causing buzzing, to help with the rest of the action issues.
You likely will never get it to be great, as a guitar it was probably not great to begin with.
Hope that helps!

[rcc56]

The string tension is more than instrument can stand.
Try going down to 32's for the D's and 17 plain for the A's and see if it helps.

The fingerboard can be removed and the neck reinforced, but that's several hundred worth of work. Add another $75 to $90 for a nut, and the repairs are going to approach or exceed the market value of the instrument. And we don't know if the neck would have to be reset, or if the braces are snug.

Lighten the load and cross your fingers. If it doesn't work out, you may be better off looking for another instrument. Remember that most Kay's were budget instruments when they were new, and were not built as well as most of the higher priced US instruments.

[belbein]

My take? Whatever you paid for it is a sunk cost. No sense in regretting it. You thought you were buying a mandocello, but you were buying an experience. Now you have two years of experience with a mandocello. Did you find that you liked it? If so, buy a better one; if budget is an issue (isn't it always?) buy mid range and buy used. If you didn't like it--as my sons say, "if it's not a fxxx yeah!"--then let it go. It's not worth the trouble. And I never, ever say that.

[pops1]

I would remove the fingerboard, straighten the neck, and reglue the fingerboard. Use lighter strings and it will last for a while. Less money than adding the stiffener in the neck, but will give a lot of results. If you are able to do it yourself then definitely add a stiffener in the neck, or if you want to use a heavier set of strings then add it also. It won't be as strong without a stiffener, but will cost less and with new glue shouldn't creep for a while. If you can use Hot Hide Glue.

[CES]

Unless you want to play slide mandocello, I agree with belbein...unless you want to learn some hard core luthiery. Eastman is making some nice MCs under 2 grand. There’s also David Wishnevsky, who builds unusual looking but very affordable instruments (last time I checked his MCs were in the 600-700 range, but I admit I haven’t looked in a while). You can also find some conversions with more modern guitars that can handle the string pressure better, sometimes pretty inexpensively.

I had a similar issue with an Ovation (Applause) guitar I bought cheaply to learn slide on without beating up my nicer guitars (before I was educated about nut widths; the internet was in its infancy at the time). It didn’t handle the heavier gauge strings well at all, needed a neck reset (not happening on a < 200 dollar instrument), and it found its way into a fire pit when I downsized (I recycled the back and hardware). The education I got from it was worth it...

If you have the budget, Weber Yellowstones are wonderful instruments...

[Richard500]

Random thought: since you actually had contact with the fellow who made this, he might even appreciate knowing where the problems are, especially if he did, or does, more of these. In my business, I’d usually benefit from knowing about customer failures, and happy to fix them when it made sense. Usually, if not always at no cost.
Otherwise, what we know is that you like the sound, or the tonal range, and would like to keep playing, so even a total write-off is not the end of the world.
As far as an ‘engineering’ fix, I have the same doubts as the builders here and no good ideas since the bend is progressing, unless you’ve got excellent woodworking skills and the motivation.

[Nevin]

A couple of thoughts: Have you checked with a straight edge that the neck actually is bowed. It is hard to tell from the pictures but it looks like the neck angle is bad. Kay instruments are notorious for bad neck joints.

[Michael T]

Thanks everyone! These are some good ideas, and I'm not exactly sure which one I will go with yet. Since the instrument isn't very valuable, I think it would be kind of fun to try and work on it some, and at least learn a little bit along the way even if I don't get it into a playable condition. I guess I do have more time to mess around with it now than I would normally...

[MikeEdgerton]

Looking at the neck joint in your your picture full size appears to show that the neck joint failed at some point in the past already. That looks a whole lot like someone shoved some sort of putty or filler in there already. Can you move the neck with the strings off? There are some fairly easy alligator dentistry type fixes for that as long as the value of the instrument isn't an issue.

[Richard500]

Looking at the neck joint in your your picture full size appears to show that the neck joint failed at some point in the past already. That looks a whole lot like someone shoved some sort of putty or filler in there already. Can you move the neck with the strings off? There are some fairly easy alligator dentistry type fixes for that as long as the value of the instrument isn't an issue.

Mike, alligator dentistry is very easy since they regenerate their teeth. We used to call the process ‘agricultural repair’ although that might insult a few folks. Since Nevin hasn’t reported back on whether the neck itself is bowed, and it does look like neck joint failure, I think you’re right, and some added metal would do the main job. Even the nut problem might be tolerable once the strings come back down, as the strings would have less spreading going on. If it had an oval port instead of f’s, I’d even call it trivial ag work.

[MikeEdgerton]

I created this rudimentary drawing years ago to illustrate how to fix the problem in a cheap mandolin. If you were really good you could use it to hold a strap button in place, again assuming the problem is a loose neck. If the neck is bowed it's a different story.

[Michael T]

Looking at the neck joint in your your picture full size appears to show that the neck joint failed at some point in the past already. That looks a whole lot like someone shoved some sort of putty or filler in there already. Can you move the neck with the strings off? There are some fairly easy alligator dentistry type fixes for that as long as the value of the instrument isn't an issue.

Mike, you are correct about the neck joint failing in the past. I went back to the original add from when I bought the instrument and saw that it was described as having "a screw in the neckjoint covered with putty to hold a reset in place." Is that the same as the alligator dentistry fix that you were describing? When looking inside the instrument, I could clearly see a large screw coming through the neck block. I tried to get a picture, but it was easier to see in person.



I did check the neck the neck more carefully for a bow, and there is some, but maybe not as much as I originally thought. If the neck angle has changed over time even with the screw in place, then that is probably not a good sign. I can't get the neck to move now, so the screw seems to have stabilized it. I guess it is possible that the original neck reset also wasn't at quite the right angle. Either way, I'm thinking that the neck angle is more of an issue than I initially guessed.

Thanks again everyone for the responses!

[Nevin]

Since Nevin hasn’t reported back on whether the neck itself is bowed, and it does look like neck joint failure,

Not my mandocello. I suggested the OP check on the straightness of the neck.

[Richard500]

Michael, first, sorry, didn’t use your name on my post. Anyway, the photo tells all. Whomever ran that screw in did not pre-drill, and it looks very much as if it split the block, which has grain running left-right. It may or may not have ruptured the glue to the interior as well. This is sort of bad since you now have two, disconnected blocks. The head of the screw is probably buried under the ‘putty’, but you can find it by excavating with a knife. All may not be lost.
The simplest version with the least tools is, I think:
Find the screw head and back it out. It should come out very easily. Also dig the putty or filler off the neck and inspect for busted glue in the joint.
If you had a hypodermic and some very thin tubing, you could squirt some into the cracked block, but that’s difficult, so we have to do something else.
The else is seeing if you can bend the neck to the proper angle. Not being a luthier, and not having a special jig, I’d loosen the strings a little, not completely, strap the body to a table and use weights on the neck, or whatever you can rig. I’d say far enough so the strings are actually parallel and touching the high frets, because there will be springback.
If that’s working, now take a 1/4” or larger drill and drill back where the screw was, all the way through. (17/64” if you have one). At the hardware store, buy a 1/4-20 hex head bolt, nut and two washers, longer than that screw by, say, 1”. If you can find a nut with an attached flange, so much the better.. To do it right, you’d want to carve the neck around the hole flat as big as the plain washer is. Then the tricky part: Put the plain washer under the bolt head, put the bolt through the hole to the interior.
If you can get that far, you’d have to get the serrated washer and nut, or flanged nut onto that bolt, which can be done with some frustration, using a long tweezer, a piece of wire and glue, or whatever. You could also, with slightly less difficulty, put the bolt in from the inside, with the washer on. This leaves a trimming problem outside.
To tighten the bolt, you need a small 7/16” wrench, or preferably a socket, and you have to keep the nut inside from turning until it catches on the wood. There is no common tool for this, but you can lever the outside washer so it pulls the inside nut against the wood while you tighten. I did say tricky.
Once the bolt has a light grab, then adjust the neck to the better angle, run glue into any exposed crack, using a thin blade to force it in if you can, and tighten the bolt. Check the angle again.
Variants: 1)Drywall bolt anchor - which comes in different sizes. The interior piece has wings that grab very easily, and any suitable bolt can be used. 2) Particleboard bolt anchor (don’t know this thing’s real name, but the hardware person does). This requires bigger drills, and maybe a specialized tap, but can be done entirely from the outside. 3) The really gross and visible solution: Two small angle brackets, one on each side of the neck at a thick point, wood-screwed through the body into the block and into the neck. Requires predrilling, is not adjustable, and will look horrible. 4) As recently mentioned, if there’s a tail pin work can be done through it, or an enlarged hole. Requires very long and appropriate tools, And skill. 5) setting the neck at the proper angle, drill and run close-fitting dowels in a few places.

If this all seems unlikely, as it probably does, just loosen the strings alot, find that screw head and take it out. If the neck then comes completely or nearly loose, you’re in very good shape since you then can take the neck off, dowel, screw and glue it back together and even repair the cracked block.
Again, I’m no way in the trade, so anything I say is not based on relevant experience.