"All About the Bass" -repair in Progress





Introduction: "All About the Bass" -repair in Progress

About: Danish cabinet maker and furniture designer. Now living in Sweden with my wonderful wife and two little girls. I absolutely crave creation. Any process that enquires getting ideas and making them come to l...

This instructable is based (bass-ed) on an old double bass that I bought some years ago. The previous owner had it looked over by a proffesional instrument builder, that more or less declared its death. It had been repaired so many times, that there was repairs on the repairs. the amount of hours it would take a proffesional to repair this instrument would greatly surpass the value of it. But I have time and I have the will to do this, so I bought it and began my journey.

Step 1: Some of the Damages.

The main reason that this bass couldn't be played any longer was because of the neck. Recent repairs indicated that the head piece had broken off, or at least had started to break off. To repair this would mean that an entirely new neck had to be made.

I found a workshop that deals with violins and cellos, and had them have a look at it. Together, we came to the conclusion that the procedure for the neck repair, should be the same one as people used in older days to extend the length on the neck for violins. Not sure, but I think the procedure is called "anschäftung" in German.

This basicly meant that I would keep most of the head piece, but would have to hollow it out a bit, to make room for a new neck. Fun!

Step 2: To Make an Omelet, You Need To...

This was the scariest part of the process. I didn't know how it was put together, so I had to try my ways arround. The fingerboard was glued on with hide or bone glue, so taking it of didn't take that much of an effort. All I needed was to apply heat to the fingerboard for a short while, and then the glue had softened enough, so that I could pry it open and detach it.

It wasn't untill then that I found out just how bad the bass was damaged. The headpiece litterally fell off when the fingerboard came off.

After taking the necessary measurements on the length of the neck and angles and all, i finally amputated what was left of the broken neck.

Step 3: Making and Inserting the Neck. Pt 1

I had a piece of scandinavian maple for the neck and the grain seemed a bit bore coarse than the on the old neck, so in order to strengthen it, I cut it in half and mirrored the pieces and glued them together. In that way, the pulle in the arm will be greatly redused, when affected by humidity.

Unfortunately, I forgot to document when I hollowed out the head piece :(

It was done with a deep hole cutter; a kind of horizontal drill with a router bit instead of a drill.

Step 4: Making and Inserting the Neck. Pt 2

Here you can see how I fitted in the neck into the head piece. After proper glueing (I used a standard white glue), I chiseled out the insides of the head piece to bring it back to its original shape.

Step 5: Bring Out the Lathe (and Other Stuff)

Since this project wasn't a restoring project, but rather a repairing project, I took the liberty to turn some new knobs for the machine head and the end pin. I also made a new tailpiece. I found a good slab of makoré for this. It is a lot harder than the maple that had been used for the older parts, so I hope that it will give a better sustain and not be too brittle.

Step 6: First Test

Here I am testing out how everything fits. It still has a bit to go, but I'm getting there.

Step 7: Cosmetic Repairs

The bass had some pretty serious damages on the sides. They had been worn down quite a bit through extensive use, I suppose. I had to replace some parts of the top with new wood and a new black and white - thingey (forgot the name on those things)

The archtop on the bass is made from two huge pieces of spruce, so I found a new piece of spruce that had just about the same kind of coarsness in the grain as the archtop. I had to wash of the lacquer so that I could get a better picture of all the damages. It almost looked even more beautiful withouth the lacquer. When the dark color came of, it exposed some marvelous medullary rays that otherwise hadn't been seen. When I lacquer it again, I will make sure to use a brighter color, so those rays will show.

Anyway, i lined up the grain in both pieces, so when the new piece has been patinated to look like the other, you will not be able to notice the repair.

Step 8: Mounting the Fingerboard.

Most of this was made long before I discovered the wonderful world of Instructables, so I unfortunately I have lost a lot of footage on my work. Though I hope that repairs won't be necessary in the future, i took the precausion of using bone glue, so if anything ever (knock on wood) should happen again, it would be relativeliy easy to repair it.

A while has gone since my last entry on this project. Here you can see the glued on finger board. I used HHG (Hot Hide Glue) for the mounting. I came to enjoy working with HHG quite a lot. It has different abilities than you average Joe wood glue, and it shrinks a little when it cures. That actually helps in making the seams a lot tighter.

Step 9: Mouniting the Neck. Super Scary!

Ok, so maybe a lot of people that know how to do this will facepalm seing this picture, but I didn't really have any idea of how to mount it the right way, so I had to improvise. I had my dad help me out on this step, and we even practiced it a couple of times before glueing.

What I did was this:

1. Obviously started with aplying the glue.

2. Panicked!

3. Inserted the neck in the dovetail shaped fitting on the body.

4. Used a cargo strap to apply the inwards pressure on the fitting.

5. Mounted the E-string and the G-string to aim in any last adjustments on the angle and also to increase pressure on the fitting.

Believe it or not, but it actually worked! The neck was as straight as I could have hoped for, and completely fixed in its posistion. Phew!

Step 10: Putting Back the Sound Post.

When I first bought the bass, I was a little surprised to find a stick rattling arround inside of it. I was about to throw it away, when a wise old violin builder told me that it was a sound post, and that it had a crucial role in transporting the sound waves out in the entire body of the bass, thus giving it a substantial increase in sustain. It also relieves some of the stress from the pressure from the bridge.

So this is how I mounted it back.

1. I took an old shoelace from a pair of boots, and a wire coat hanger, brutally deformed into a hook.

2.I tied the shoelace arround the post and used the wire coat hanger to grab the lace from inside the body.

3. I could see a small depression in the wood inside the body, where the post had been before, so after a bit of tinkering, i finally managed to put it in place. I then used the shoelace to tighten it against the inside of the deck.

4. Voilla! the sound post was back in its spot. I used the coat hanger to untie the knot.

Step 11:

Step 12: Making a Nut. Stevie Wonder and Paul McCartney Would Be Proud.

The old nut had gone missing since long, so I had to fabricate a new one, but where do one find Ivory in these days?

I was lucky to find out that one of my friends were about to through out a really old piano. I payed him a visit with my trusty old handsaw, and gave that old piano a brutal finish. I sawed of all the keys. So all of a sudden, I had quite the collection of both ebony and ivory to work with... Recycling is sexy!

So I made the nut of the piano ebony, with a white stripe of Ivory through it, so I will always remember where it comes from.

I then used my handfiles to mark out where the strings should be. I had my little assistant with me as well, never know when you need good advise from a two year old.

In the last picture you can also see that I mounted the pegs. I need to replace the screws one day. It feels a little cheap to use regular wood screws instead of brass screws.

Step 13: Adding Shellack

I bought a small bucket of shellack flakes. Since i fell in love with the fantastic pattern on the top plate created by the medulary rays in the spruce, I wanted to use a finish that had the least amount of color.

Making shellack was surprisingly easy. I took som alcohol and some flakes ( I can't remember the excact sollution) I put both of the ingredients in a small mason jar. I then put it in a pot with hot water. Not boiling hot, just warm anough to speed up the dissolving process. When all the flakes were completely dissolved, I had my very own ready-to-use shellack.

I made a small ball out of cotton using an old cut up t-shirt. I then dapped the ball in shellack, -just a little bit, and then, with small cirkular movements, apllied the shellack to the bass.

The bass was already pretty roughed up, so I knew beforehand, that a perfect piano glossy surface would be impossible to achieve. I didn't have any ambition of making that either. I just wanted a silky-glossy finish, which I think I managed pretty good.

Step 14: Assembling This Thing! Weeeeii!

Sorry for the lack of footage here. In this single picture, you can see me making a make shift sollution for the tail gut. I used an old E-string from another bass, that I didn't use. This has worked out ok. I need to get my hands on a real tail gut one day, but this wil have to do right now.

The feeling you get, when you apply your strings and start tuning them is nothing less than overwhelming. It was a magical feeling to actually be able to play this instrument finally.

Step 15: End Result! Me and Blondie

So there we are! Providing smooth dinner music at a big summer event for young adults in stockholm.

I learned from one of the many kind comments, that an unvarnished bass is called blonde, so I named the bass "Blondie".

She sounds fantastic! It feels good to finally be able to play an instrument my own size.



    • Woodworking Contest

      Woodworking Contest
    • Casting Contest

      Casting Contest
    • Oil Contest

      Oil Contest

    We have a be nice policy.
    Please be positive and constructive.




    My high school has an old bass. the thing is in worse condition than yours by the look of things, but you give me hope to repair it! if I have questions on the bass, can I ask you?

    3 replies

    You are welcome any time! I have contact with a bunch of old violin builders as well, so I would probably be able to answer most questions.

    Guess I should give you an update; the director wouldn't let me touch it. I graduated now, so it looks like I will never get a chance to try.

    Man, that's too bad. Maybe you will get lucky and find one later.

    I love this, and can't wait to see how it turns out. Think of the "life story" this bass will have several years down the road!

    So cool, and very inspiring. Thank you for posting the progress up to this point. Be sure to leave a comment when you update this, which will bring me back to see more! :)

    1 reply

    Still pretty bad footage, but I managed to finish it and have even played a little concert on it already. Take a peek;)

    Hi treenerd,

    From what I've seen so far you are doing a great job in bringing life back to this old guy! I particularly like the pegbox/neck graft you did, though hot hide glue (HHG) is conventionally preferred also for such a repair, over white (PVA) glue. It is particularly important to use HHG for the fingerboard, as it enables future removal. Fingerboards wear.

    I cannot judge what kind of double bass this is, but it might be a Germanic shop bass from the first half of the 20th century. But it might be something totally different as well; is there a label inside? While the screws used in previous 'repairs' have degraded the value, it can still be a competent instrument. If you would like to know more of its provenance, you could consider to post on talkbass.com (or maybe geba-online.de) and you may get more information.

    If it has not already been done: what varnish are you considering for it? Alcohol/shellac-based, and oil-based are common choices, but it should best match the existing type.

    Congratulations with your repair, and I would love to see the finished instrument!

    2 replies

    Thank you so much for your usefull comments, Borrutje!

    You are right with regards to the glue. I still haven't glued the neck back on yet, but will be using hide glue for it. I did, as a matter of fact use hide glue for the finger board.

    I have felt the temptation to start the project over again and router out the old graft and replace it with a new one, using traditional materials and methods. However, as I have studied the instrument closer, i found that the back and the sides of it is made from regulager lathed plywood, and not even a particular pretty kind. The glues used for making plywood are most definately not animal glues, so even though I like to stay true to the old crafts, I don't feel so bad for having used PVA glue for the graft. I just really, really didn't want it to break again :)

    Right now, I have started it up again and are making attempts to repair the worn down parts of the sides of the deck. I have a friend who owns a guitar workshop. He has both the bindings and the hide glue that I need to make those repairs.

    I recently purchased a box of shellack flakes. Since I was able to wash of most of the old lacquer with alcohol, I would assume that it indeed is alcohol based shellack that covered it before, so I will proceed with shining that up, when the repairs are done. I will, however, use a color as neutral as possible. I don't want to give it that same old varnished look that it had before. Those incredibly beautiful medulary rays only appeared when i removed the old shellack, so I hope that I can keep them visible by adding an almost transparent layer of shellack.

    Thank you for the tips on the pages! I will have a look at them for sure!

    Right, now I see your bio - you're a cabinet maker. That explains your professionally executed graft. Now that that graft is done in PVA, I would just leave that be, PVA is strong enough, and a well-fitting joint with just a thin layer of glue should not creep either. PVA never really gets hard, and can therefore cause some damping of acoustic vibrations, but again for a thin layer that is not an important issue, and certainly not in the pegbox.

    Yes I was wondering about the back. It gave the impression of being ply, but I could not quite see. Or maybe there is an extra layer (with PVA?) over the button (that is the connection between the back of the heel and the back plate, where all the screws are, 4th picture). In my mind I had given it the benefit of doubt and assumed it would be a solid flatback (which are more common). But a long time ago I had a ply flatback as well, also with a solid carved top and ply ribs, just like this one. In fact, it may well have been quite similar to yours, but it was a long time ago and I have no photos. The ply makes it probably a little bit younger, say 1930-1960. Mine came from Hungary, but was not necessarily made there.

    That top looks quite spectacular indeed, and that deserves to be preserved. An alcohol/shellac based finish is common in these sort of instruments, and I too like my instruments on the lighter side ('blonde' as it is called). Indeed, adding a stain to the final layers reduces translucency & can mask wood structures. On the other hand, entirely without stain can make for too bleak an instrument. You can consider to apply a water-based stain before french polishing; examples of this are attached (no filler was used). I would suggest not to sand all the dents & scratches away, in my mind (and in the mind of many others) it is OK for an instrument that has lived many decades to have some blemishes. It does not need to be new. Furthermore, fillers may impede acoustic performance, and for that reason also best keep your layers thin.

    Those screws in the back (in the button & in the neck block) are a bit of an abomination, in my mind. But as it is, they are probably required for structural integrity (to withstand the tension of the strings). If you just want to bring the instrument back to working order, you can leave them in, but if you want to improve the instrument, that area requires more attention. But then you are talking about restoration rather than repair, and it is likely to involve replacing the entire back. That is quite a bit of work & exposure, not to be taken lightly, including the bend in the back, and probably purfling (double basses & violins have purfling, no binding), and depending on the wood you choose may cost a bit too. (On the instrument I referred to above I did replace the back for a solid maple one, but without purfling.) Maybe best seen as a later stage upgrade.

    Though less focussed at double basses, it might also be useful for you to browse maestronet.com & mimf.com.

    Good luck!

    Top (light).jpgBack (light).jpgBack (dark).jpg

    WOW!!!!! Those tuning machines!!! I've never seen a bead head on the back end of a mechanized peg or a mechanized peg with a wooden post --I like it!!! Do they have a maker-name engraved anywhere?

    1 reply

    Yeah, I like them too. It is a neat combination. I have tried for a long time to spot any names or brands on it, but thus far, I haven't had any luck. The design of the shape has been arround since the late 1800's but the use of rubber on the resting pole along with other details, would indicate that it is a great deal younger.

    The "black and white stuff" you referred to is called binding. It's done a lot in making guitars (acoustic and electric.) Nice work.

    2 replies

    The "black and white wood" is actually not called binding either, although it acts like one. The proper term is "Purfling" https://en.wikipedia.org/wiki/Purfling the two black pieces of hardwood is ebony and the white is maple. The strips help prevent cracking of the top and back of the fiddle. Great work Treenerd, keep it up!

    Thanks for clearing that up! My vocab is a little rusty.

    Really looking forward to seeing how this works out! Keep us posted!

    1 reply

    Will do. Thank you.

    I have a double bass that I purchased new in 1950-1 when I was a teen. We are very close old friends. He still stands in my living room although, due to arthritis and diabetic neuropathy, I can no longer play him.

    Several years ago I undertook to re-glue his back. A nothing job compared to what you have been doing. Because I was unsure of myself I used what I later learned was a 3000 year old formula called fish glue. I read that it was very strong but would release its grip with water. It is probably the same as your bone/hide glue.

    I purchased a bunch of large clamps and proceeded gingerly.

    It is still together.

    Your skill and talent awe me. I eagerly await your next instalment.

    Thank you,

    Mickey Oberman

    2 replies

    By the way, fish glue is excellent glue! I believe animal glues are the second step in the evolution of adhesives, where sap and tar most likely were the first ones. Organic glues are interesting. They have a lot of unique abilities that most chemical glues don't.

    Thank you so much! It has been a long process so far, but constructive comments like this, help me get to it again and finish it.