It all started with a little unexpected package I picked up the day before Christmas Eve 2015.
Nothing less than a Levin guitar mandolin from 1901! Hermann Carlsson Levin took one patent on the 1897 while still working as an instrument manufacturer in New York, USA. It is the oldest Levin instrument I have come across. This very special variant was made quite a lot by the very beginning of the Levin era when the factory was started in 1900 in Gothenburg.
It had some obvious issues that needed fixing. The paint was "improved", cracks were both repaired and new, the stable was replaced and the specially made string holder for the mandolin neck was missing. Most problems caused by an amateurish and unfinished "renovation". The owner gave me free hands to get it playable again.
Even before I started working on it, I very much believed in the instrument type. Ordinary harp guitars with bass strings are a failed instrument when I think too many string reverbs from the bass strings, the short menstrual clock on the Mandolin strings does not swing by as much.
A study inside with the hand revealed that it had the same knit in birch / birch during the guitar stage as all early Levin parlor guitars. It has to be removed and replaced with spruce as it is a real killer and the owner wants it to sound as good as it can. Otherwise, I wanted to keep it as much original as I could without compromising on sound quality and playability.
Take it apart in parts
Fortunately, all the tuning screws were in good condition and nothing was missing except the string holder and the stall for the mandolin neck.
Put aside other jobs over the Christmas and New Year holidays and started to take apart this very exciting instrument!
It was a lightweight construction, bottom and cover 2.8 - 3 mm, side 2 mm. Definitely not covered! The biggest problem (as always) was the beginning but not the renovation. The guitar neck was turned and also sat with two screws from the inside. Was fined by the one who did not appear through the sound hole. Got it loose in the end, although I get to work a little extra with the neck pocket that got hit when the glue was modern and sat more it should. The grip board was cut at the 12th band, so you used to do when you did not know better and put neck around. Mandolin board and neck were pristine and were very easy to get loose without any flaws.
The guitar neck is in al, the mandolin neck possibly in maple or pear wood. The grip boards in brazilian rosewood. Incidentally, both necks were very comfortable to stick with my favorite shape, a soft V. The neck foot and neck pocket have the nice bend that Levin had at the beginning of his manufacture, only the very oldest are made in that way. It will be neat but weaker and of course harder to manufacture. They went to a straighter side after a few years.
The neck block for the guitar is el, while that for the mandolin seems to be in spruce. Mahogany base block - three different types of wood for approximately the same function 🙂
Carved in al and made according to American tradition, later Levin parlors have a solid birch or maple strip which is the European tradition. The ribbing was simple but well-planned and a little under-sized, especially for an aged and brittle lid. All the wood had become brittle and light, probably the instrument was not stored in the best way. All the bottom ribs were half loose.
New colored varnish had been applied during crack repair of the lid. You see that you used red stain to color the entire instrument before you painted, a little red scratch on the inside of the lid. The stable also sat properly but got loose. A little wood fiber came with the modern glue.
After the ribs were released, it looked like this.
Mandolin stall in original
Got some pictures of the missing original figure for the mandolin.
Lock: 2,5 - 2,8
Page: 1,8 - 2
Total length cm
Neck length cm
Lid maximum width cm
Grip board: 29
Very deep cm
End plug: 10,2
Grip board width mm
Upper seat: 47
Upper seat: 31
Maple knit: 330 x 32 x 3,1
Triangular rib cover: 9 x 11,5 (3,5 wide at the top), flat
Triangular rib bottom: 8,5 x 11 (4,9 wide at top), weak radius
Neck block / bottom block mm
String pin hole
Center to center E strings: 56
Guitar 63 cm
Mandolin 34 cm
Guitar 2 mm wide, 0,5 mm high. White metal
Carbon fiber neck
One thing I always do when I have the chance is to put a carbon fiber rod in my throat. It really is needed when the neck is soft like these in alto wood, you can ignore it if the neck is in hard maple / pear wood but in practice I always do it when the grip board is loose. Then you can trust that the neck does not have to be changed when you pull up because it bends off the string. A slightly brutal procedure with only positive features that is not visible when the grip board is glued back on. A groove for the 1 cm square hollow (8 mm round hole) carbon fiber rod is cut into a jig.
The carbon fiber stick is glued in with a very sticky epoxy glue, the necks are clad in a happy pack to protect them from glue. The hollow carbon fiber rod in the guitar neck received a solid round carbon fiber rod in the upper part and a round rod in birch in the rest of the cavity. The mandolin neck got a less solid carbon fiber rod glued. The rods are covered with wood so that the grip board can attach well with skin glue to the neck. Also reinforced the neck of the guitar neck with a burgundy round bar in birch.
It is always good to replace the old brittle ribs with new wood. New wood is tougher and makes the brittle lid last better. Then the old ribs are usually oversized and have lying veins and be placed in the wrong places. In this one, the ribs were good except for the stick under the stable, so I made copies in nice Swedish spruce that was only one or two mm higher.
The cracks were secured with team lists (now I do them a little differently).
The bottom ribs were glued, kept the two ribs visible through the sound holes in the original.
The lid received a slightly different ribbing to improve the tone and make the lid stronger. The stick was replaced with a barn plate in spruce with an extra reinforcement at the stable. The string pins for the guitar string got reinforcements in the bubinga to hold for the string balls. Used one of the original ribs for the new extra rib behind the stable.
Small stop blocks on the ends of the ribs in the maple and a repair of a notch that was broken were inserted. The knits in spruce across the lid cracks were sanded down to low semi-circular shape. The screws for the mandolin stall were given a lock washer. The wound in the carving after the old maple stick was filled again with spruce wedges.
The broken saw board
Used my Dremel to cut out a hatch for a reinforcement on the underside of the chopped guitar grip board. Glue a piece of rosewood with epoxy plus abrasive dust in rosewood. Selects the glue because it fills in well and so that the repair does not fall apart at the next throat turnover.
Fortunately, there are simple holders for mandolin strings that are very similar to the original. Saw off the piece that is screwed onto the lattice of one such and got something that works and resembles the original.
The old stable brought along a lot of spruce fibers (modern glue) so I decided to cut open a hatch and refill with new spruce under the stable. Then glued with epoxy glue for the same reason as before, next time the stable is soaked and heated loose, the spruce patch should not come with. Made a replica pyramid figure in matching rosewood to the grip board. The form follows early parlors and pictures of other complete guitar mandolins. The original stall was probably incorrectly mounted, the new stall I unloaded was more properly glued but revealed a little unpainted fir closest to the side. Did the replica a little longer and hid the wound more. A little wider also with the string pins farther back to make room for an intoned stable leg. The grip board later glued about a mm higher up also for the sake of intonation.
Bonding of the bottom
Before the bottom was glued, I made two antlers to be able to force the grip boards when the necks are to be glued.
The bottom was glued in batches with warm skin glue. The bottom had shrunk a little. The simplest and best solution when the bottom just shrinks a little is to pinch the sides at the waist slightly so that the bottom protrudes about 1 mm there. The perimeter decreases and you can make the rest of the shrunk bottom fit. The excess at the waist is scrapped away. You can hardly see it if you do not measure. The alternatives are to insert a centerpiece or to put more wood on the bottom, which is usually a bigger intervention. Scraped the edge of the bottom after gluing, became good.
Bonding of neck
Inserted a maple sky into the guitar neck hatch. 3 mm thick, which means that the intonation point on the stable gets right without having to push the grip board too far. Also gives strength to the joint, a soft neck pad may otherwise give in when the strings are tightened. Screwed in the two screws as well. Glued both mandolin and guitar grip board with skin glue. Started by gluing the mandolin neck.
The fingerboard on the guitar neck got a "slope off" of 1,8 mm - a little too much! Made a wedge to glue under the part of the board that rests against the lid. Here is a small series of pictures of how I make them.
Uses my most serious power tool, a roller polisher, to make the wedge. A stable block with the same size as the wedge is "jigged" with two loose blade measurements with a thickness of 1.8 mm on the underside to give the right slope and two pieces of masking tape to attach the rosewood veneer. The tape is taped to the block and one side of the veneer. Super glue is applied to one tape and the other is moistened so that the glue hardens quickly. The two tapes are glued together, but the tape itself only sits in its own glue against the block and veneer. Then run the block a number of times through the roller plaster until one side of the rosewood piece is about 1.8 mm. Since the tape only sits in its own glue, it is easy to pull it off without destroying the thin wedge. It does not matter that the piece became a little too short, it will not be visible (next time I will subtract 4-5 tenths on the blade measurements, someday I will find exactly right!). Then glue the wedge with epoxy glue and rosewood dust to the underside of the board at the bottom.
Filled the wound after the glued and missing stall on the mandolin part with an elongated puddle of stewmac's 20's super glue that was allowed to self-dry and fill in the irregularities. Then scraped down what stuck up with a razor blade that was taped to half the edge so as not to scrape the varnish. The stable comes from the scrap box.
The guitar has been given an "overspray" with cellulose varnish on top of the spirit varnish on the lid. Fortunately, a thin one. Then you have smeared with colored cellulose varnish at the crack repairs where you neatly fold in spruce sticks and here and there. With a razor blade it was good to scrape off the worst.
Varnished two coats of spirit varnish which were then matted with steel wool and hand polished to a semi-matt surface. Also made heel caps in ebony for the two necks. The original was made of fragrant ebonized wood, the one on the guitar neck had begun to be replaced but was not finished at the last renovation.
The customer wants new brass bands (as they are the best!). Started with the guitar neck. The most important thing when tying is that the grooves have just the right width. Has acquired a few different Japanese saws with different thicknesses that fit perfectly with the brass bands and ebony and rosewood boards (the groove in the softer rosewood can be a little narrower). Guarantees the right depth with stewmacs adjustable brackets and saw. To protect the board from marks from the abutment, I have a thin aluminum plate. The worst mistake you can make is to saw in the lid when sawing the grooves for the lower bands, always use two iron plates to not make that mistake!
Also, the lid of the mandolin string holder is aged with the help of white wine vinegar in a closed plastic jar with the lid lying dry in a glass dish inside the box. The worst glitter disappeared overnight.
After painting and banding the guitar neck it looks like an instrument! A first string of both mandolin and guitar was made with temporary stable legs in the form of drills and an old shimsat mandolin installation.
Sanding of straps and some small fixes
A few pictures of my jig to fix the guitar and neck in the position the instrument gets when all strings are on and tuned. This is a method I use on all instruments that are banded about. Starting with clamping the guitar body against the lid of my jig with forceps.
For the neck to get the same position as when playing, I open the lid on the jig before the neck is fixed. On an acoustic guitar the difference is not great, but on a heavy electric guitar or bass the difference is much greater.
In the game position, I clamp the support under the neck in three places and tighten firmly.
In the upright position, I use a clamp to push down the neck at the top of the supports the tenths that the neck rises when lying flat. There is also a twisting effect on the head from the angle of the strings over the upper saddle, when the strings are released the angle increases slightly between the grip board and head. Therefore, fixes the head with a smart strap and a wedge under the top of the head before releasing the strings.
The strings are loosened with the geometry of the neck preserved as the neck is "frozen" in its tensioned position.
Now you can flatten and round off the tops the tops of the straps. Uses a "fret rocker" to make sure no band sticks out. Polishes with 600/800 paper and steel wool. The bands are dyed on top with ink so you can clearly see when you start to take material on top of the band.
An upper leg saddle is manufactured.
Strings up and double points were the intonation points for the different strings. Note the dimensions and mark out the location and angle of the stable leg on a white masking tape. Then use a Dremel and a jig to cut up the track for the stable leg. Ensures that the stall leg gets a slight slope backwards at the milling.
The lid curved a little into the outer edges of both sound holes, glued two small spruce sticks so that the lid does not fold into the weak places.
Made a larger washer under the mandolin string holder. Now you can tighten properly!
Inserted mother-of-pearl girls in the new solid ebony pins.
While waiting for the mandolin straps, I vibrated my body for three days and put a wedge under the mandolin board. Be a little quick to glue that neck, a "slope off" of 1,5 mm on the short distance that the mandolin board is glued to the body is not so good. Now the fretboard is completely straight after face sanding before the straps are mounted. Got to be skin glue this time.
Banding of the mandolin neck
Got home the mandolin bands. They turned out to be a bit awkward as the spikes on the pliers were sharp and did not quite fit my usual saw thickness. Sanded down the thorns a bit before I mounted the straps. Then the straps were carelessly rolled up and I had to straighten each strap before mounting as well. Otherwise good!
Started by widening the band cuts, the original bands had a very thin tang on the bands. In order not to make marks on the board, I have a thin aluminum sheet that protects against the abutment on the saw. Sheet protection on the lid is a must, it is very easy to see saw across the fibers on the lid otherwise (nightmare!), Especially with such a thin board like this!
The jig where the straps are mounted with hammers and pressing tools. The tapes were pretty awkward to get there on this one, especially the ones at the bottom. Before I closed the bottom, I did two special stops under each grip board so that I could tighten the forceps properly through the sound holes.
The last step was to make an oversaddle and a stall for the mandolin neck. Started cutting notches in the upper leg. In the picture I have rubbed steel wool to make the grooves visible. 2 mm from the edge to the outermost strand, then 2,5 mm between the two thinnest strand pairs and 3 mm between the pairs for the coarsest strands.
To find the height of the stable I clamped a 0,3 mm thick blade with a capo instead of working to get the grooves in the upper saddle right. Laying shims under the temporary stable until I got 1,2 mm at the 12th band and the thickest string pair.
Made a topic in rosewood for the stable, which for the most part I used the roller tips to get a nice square piece with the right dimensions. To cut a groove for a stable leg, I used the stewmac jig for stall leg milling in a different way. Tightened the piece in the small screw piece and fastened it to the bench with a clamp and the jig on top to just high wooden pieces with more clamps.
A first test where I made tracks for the strings and the finished stable and the saddle.
The last thing I needed to do was to mount the nice leg knob at the back. It had dropped its mother-of-pearl inlay, drilled up and mounted a 5 mm mother-of-pearl.
Fine pictures and a video
Both the mandolin and the guitar sound really good! In class with the best Gammel Gura I've done so far 🙂
Mats Byström recorded some sound with the guitar mandolin at TonTeknik Recording in Umeå!