OK the K-5 Mandocello project is back on!

[Bernie Daniel]

I found another L-50 today and bought it.

This one is a 1942 model with a broken headstock. Pics included below. The luthier I use here in Ohio will be doing an intensive repair on the headstock -neck break.

First he will eveluate the current repair and probably re-glue it as it looks absolutely horrible in the pics.

Then he either mill or cut 1/8 inch thickness off the entire top of the headstock - I want him to cut is so I can save the silkscreen "Gibson"! Then he'll overlay the entire top with a 1/8" panel of ebony -- it will be cut to leave 1/16" on each side of the headstock to provide a binding channel. The headstock will have "The Gibson" and the flowerpot like the K-5.

The back side of the break on the neck will also be milled out and a fresh piece of mahogany glued in an then reshaped and refinished. When done this area will probably be stronger than it was before the break.

Then the "usual" will happen:

1) replace the old rosewood fretboard with an ebony mandocello board adding a StewMac hot-rod for a truss,
2) then bind it with the old binding (we'll need to find a little extra for the extension), add the frets,
3) make a new mandocello trapeze tailpiece (I'm getting better and better at that), make a new mandocello nut and bridge.

I'm debating whether to go with gold or nickel hardware - I like gold but the K-5's were silver. But I'm thinking gold because it is not my intention to MAKE a K-5 but to make a mandocello that LOOKS like a K-5.

Pics of the guitar before the conversion starts. I'm going to try to get photos of every step of this conversion as I have had a lot of email expressing interest in the process.

I'm excited about doing this project without taking a good L-50 out of the market.

[Rvl]

I wish I had a luthier that would do the work
I asked a few here in Japan and they were like.....huh
I tried to do the work myself ........ahhh

[Jim Garber]

3) make a new mandocello trapeze tailpiece (I'm getting better and better at that)

I may have missed your trapeze work on your other conversion threads. How do you create a new one? I would think to use the existing and replace the crosspiece with hardwood or metal and 8 holes for strings. Or do you replicate the K5 tailpiece?

[Bernie Daniel]

I may have missed your trapeze work on your other conversion threads. How do you create a new one? I would think to use the existing and replace the crosspiece with hardwood or metal and 8 holes for strings. Or do you replicate the K5 tailpiece?

Hi Jim! You missed my trapeze work? The Barmum-Bailey/Ringling Brothers circus came through the NY area last week and you could have seen me in action. I have stayed on past normal retirement age because in trapeze work your duty is to catch young women in swim suits all day.

I make them from a regular Gibson style tailpiece and some 1/8" metal round stock -- either brass or steel. These two mandocellos have tailpieces that I made. You probably saw this pic but was not looking at tailpieces specifically.

I have some better pics of these but you get the idea. The one on the Epiphone is nickel with gold on the Vega. I have been practicing engraving and will put a big Epiphne "E" on the nickel one and "The Vega" on the gold one.

Oh the cross piece? In the case of brass I merely add an another length of metal stock at the junction of the two ends and solder it. For the steel I braze it.

[Barry Wilson]

I love watching this stuff, living vicariously through the thread. I did one build and am still cleaning sawdust in my garage. I'm no woodworker...

[j. condino]

The Stew Mac "hotrod" is quite a beast of a truss rod. You'd be fine with a simple compression rod like the original style. As much as I like a solid neck, it always bums me out a little when I see what was once a nice old instrument with a few neck issues that someone else decides to "fix" and then it goes to the other end- massive truss rod, multiple oversized carbon fiber beams, giant new stainless steel frets. et al. Then they bring it by for me to check out and you can tell that the neck issues have been corrected.... but now everything is so out of balance that the neck and body no longer couple and you have a " dead", unresponsive instrument.

Technical nerds may argue my jargon and methodology, but someone who actually plays the instrument can tell instantly.

So what does a fellow do with that many mandocello conversions? I believe you are up to four now!

j.

[Rvl]

The Stew Mac "hotrod" is quite a beast of a truss rod. You'd be fine with a simple compression rod like the original style. As much as I like a solid neck, it always bums me out a little when I see what was once a nice old instrument with a few neck issues that someone else decides to "fix" and then it goes to the other end- massive truss rod, multiple oversized carbon fiber beams, giant new stainless steel frets. et al. Then they bring it by for me to check out and you can tell that the neck issues have been corrected.... but now everything is so out of balance that the neck and body no longer couple and you have a " dead", unresponsive instrument.

Technical nerds may argue my jargon and methodology, but someone who actually plays the instrument can tell instantly.

j.

I have 2 archtops with bowed necks and lifting frets
I was thinking of doing the same thing and installing a new trussrod ,carbon fibre and ebony board
How far would you go to modify old instruments?
Sorry to take this off topic

[Bernie Daniel]

.....So what does a fellow do with that many mandocello conversions? I believe you are up to four now! j.

Odd that you should mention that -- my wife asked me the same thing when the latest arch top guitar came through the door this week.

I appreciate the advice on the truss -- I do think you have a point there. When I started this "conversion obsession" was thinking that any minute the top would deform or the neck would bend -- especially since I was slimming down the necks. So I was thinking I need a lot of help with controlling deformation. Actually none of that has proven true and so far --knock on wood -- no problems. So maybe the hot rod is "overkill" indeed.

What am I going to do with these mandocellos? Well if this current project to make a Gibson K-5 succeeds and the instrument sounds as good as a mandocello as L-50s' do as guitars then I'm finished.

I will be trying to sell or trade away the other three shortly thereafter I expect.

[j. condino]

I have 2 archtops with bowed necks and lifting frets
I was thinking of doing the same thing and installing a new trussrod, carbon fibre and ebony board
How far would you go to modify old instruments?
Sorry to take this off topic

It really depends upon the individual instrument. Not much will help out an old Kay or Harmony guitar neck made out of tulip poplar with a poplar neck block. I've been in the same shoes in the past and WAYYYYYYYYYY overbuilt the inside of a neck, so much that the weight shifted and the neck was so stiff that nothing moved and I eventually wound up cutting it off and using it for a door handle. 'Funny thing is that 20 years later I have another neck in use as a door handle in the current workspace!

As much as anything, your choices in neck construction have a lot to do with how everything works. I've used a number ( maybee 50-100) of the double action guitar truss rods, often with good results; occasionally with less than ideal. The last one I used broke inside the neck, so I've cussed a lot and sworn the commercial ones off. A big concern with those is how much weight do they add to the neck and how big are they. The LMI tend to be more low profile and smaller in the threaded area than the Hot Rod. As somone who always prefers to make instruments at the low end of the weight specrtum, that makes a big difference. It only takes a little bit on a longer necked instrument to suddenly make a balanced guitar body drop at the neck end (not ideal for me).

I use carbon fiber from LMI, Stew Mac, and Dragonplate / Gemini. In a guitar sized neck, the LMI stuff seems to be much more flexible, hence the common use on either side of a truss rod. When I've used the Stew Mac carbon fiber in that manner, the neck refused to move even a tiny bit; no relief, lots of frustration. Maybee that is why their hot rod is so beefy. I use the Stew Mac carbon almost exclusively doubled up for my personal mandolins. It seems to be perfect for what I am looking for and I've removed Gibson style truss rods and installed this type of carbon in that manner and I could tell a positive difference in the sound of the mandolin- not huge, but still better to someone who already knew the voice of that mandolin; 'like you stepped on a small preamp and gave it a tiny boost. I've used solid titanium bars in a similar fashion with excellent results. I no longer use Ti bar stock, mainly because of some undescribably internal thing that just intuitively likes the idea of soundwaves hitting the the carbon a bit more than a big solid metal bar in the neck. Lots of people do it successfully...it just has my name on the headstock these days...

For my big double basses (42" scale) and almost all of the restoration work I do, I use two of the Stew Mac carbon fiber beams inside the neck. It works perfect for that, and allows me to plane the neck perectly straight on the workbench and then strung up to tension, I get just the right amount of relief (under almost 300lbs of tension with medium Spirocore strings!). No adjustability is the standard for double bass necks, so an adjustable truss is not part of it.

I also have used some of the Dragonplate / Gemini carbon fiber hollow half tube type stiffeners. They are VERY rigid and work well, but I have some aversion to having a half inch hollow channel inside my necks (on any instrument) and I have not yet worked out a way to get a good adjustable truss rod inside the whole hollow thing and then sealed up without a big mess of epoxy or such.

On the next batch of necks I'll make up in a few weeks- two mandolins, one octave mandolin (22.5"), one guitar(25.4"), and one fanndocello / cittern (27-25"), all will have a traditional Gibson style compression truss rod made out of titanium round stock with low profile LMI barrel nuts, that I make. Low mass and high tech marketing bs. Maybee 20+ (or more) years ago, I had a broken instrument with a standard Gibson style rod and I thought they were all junk and only worked in one direction. It was a huge step in my development as a builder when a grey haired old mentor looked at me and said, " Look kid... these ARE two way rods, and light ones at that. Make sure you put your best wood into your necks, and then give the damned thing a couple of turns tight before you do the final neck level and glue the fingerboard on. That way you can always loosen or tighten it...". Funny as it sounds, I somehow never got the message before that day....

Last year I had several restorations, all with different types of broken truss rods. I asked probably ten of the best living makers in the world for advice on necks and truss rods; they all gave me about fifteen different answers. I made up a half dozen test necks- all with the same high quality seasoned wood that I use for the real deal ($$$-ouch!), put different truss rods in each, and then made up a very controlled test situation and measured all the results. Guess what- almost every one of them performed the same....

'Hope that helps the six people who actually read this section of the cafe! Your results and mileage will most likely differ. If you are in the local area, stop by for a visit and you can test out a few and make up your own opinion, while we pick a few tunes and laugh a bit..

j.
www.condino.com
www.kaybassrepair.com

[Bernie Daniel]

I bumped this thread back up because I "officially" started working on the project this week. I've taken all the hardware of the L-50 and Mark Keiser will start working on fixing the broken headstock next week. I am having this done by a pro because someone needs to decide if the poor glue job needs to be broken and re-glued properly before doing the mahogany underlay and ebony over lay on the break. Here are the steps I anticipate in the conversion. I am going to call the finished project a 1942 Gibson K-50 mandocello -- designed as a K-5 but given a more accurate model name in that it came from a '42 L-50 not and L-5.

Steps I plan on (keeping in mind there will be some I don't plan on) -- I listed them as this is what I have found to be the case for the two pilot projects and also because someone else might be interested in doing it. Obviously suggestions or cautions are welcomed:

Gibson K-50 Mandocello Project Plan
Goal to create a genuine Gibson mandocello in the style of the Loar K-5 model that was made from 1922 to 1924. Gibson continued to make mandocello on an as requested basis until 1940 when the instrument was removed from the catalog. This mandocello will be made by conversion of a 1942 Gibson L-50 guitar that was purchased with a headstock break.
Steps in this conversion are expected to be as follows:
1) Redo poorly repaired headstock break with ebony overlay and mahogany underlay and re-contour and finish.
2) Inlay 1930-43 style “Gibson” script, and Gibson flowerpot in gold MOP shell (see pic -- do not why some of the MOP came out white but its all uniform gold color).
3) Bind headstock in “cream” plastic binding (or better alternative material if available) .
4)
5) Drill 0.25” diameter holes spaced for a standard mandolin tuner spacing (29/32”). Graphic mock up of headstock below:
6) Remove guitar fretboard, and replace truss rod with new two –way design.
7) Cut out new mandocello fretboard from ebony blank (slotted to24.75” scale with 25 fret slots).
8) Sand in a 12” radius to fretboard surface (may consider 9” radius?).
9) Bind fretboard with cream plastic binding (or better product if available).
10) Press in fret from Evo gold wire—guitar size (wire supplied).
11) Prepare neck surface and glue on new mandocello fret board.
12) Trim neck to fit new mandocello fretboard (note this fretboard with binding is expected to be 1.62” at the top (i.e., 1.5” ebony board and 0.125” of binding) and the existing L-50 neck at the nut is 1.74” so it is anticipated that there will be about 0.06” (1/16”) to remove from the each side of the guitar neck to fit the mandocello fretboard.
13) Refinish the exposed areas on either side of the top that was covered by the wider guitar fretboard.
14) Add gold MOP fret board markers (anticipated to be 0.25” diameter “dots” at frets 3, 5. 7, 10, 12 (two), 15, 17 and 19
15) Add black plastic “dots to the bass side of the fretboard biding exactly as indicate above.
16) Fit headstock with gold=plated Grover 309 A style tuner machines, and bushings.
17) Prepare a bone mandocello nut with a bias toward maximum separation of the two strings on the C-course
18) Make a gold trapezes (Gibson K-5 style) tailpiece, mount and adjust as required
19) Fit ebony bridge, slot to get proper string separation on each course and cut back for intonation as necessary.
20) String up with D’Addario J78 mandocello strings.
21) Tune up and play!