French Bass Brace advice

[Adrian Levi]

I have decided to take on my 'bass in a bag project' and repair this old instrument that I found in severely bad shape.
Its taken me a while to take the back off . It was epoxied to ribs with a thick barrier of the stuff all round.At times I had doubts that I would manage without causing damage but finally its off and almost cleaned of Gorilla glue and epoxy.

The bass has a typical old French brace made of a piece good looking spruce.
The upper brace I got off and can use again with a little shaping and the lower bout brace will be replaced.

My question is should I replace the large brace or not ? This would be a consideration for tonal purposes if it applies. The brace is glued on with hide glue and has stayed original by the looks of it.
It would make great wood for the repairs that the top will be needing. Any advice / insight would be great ....

[Adrian Levi]

In the interim I have decided that it would be the correct thing to just keep the brace as the maker had envisioned . Its French after all .

[Ken Smith]

In the interim I have decided that it would be the correct thing to just keep the brace as the maker had envisioned . Its French after all .

So why ask? How many French basses with this single wide center brace have you seen before? Usually, they are taken out and re-braced traditionally and the sound is usually improved with it. Also, if you are repairing the center seam as it looks from your pics, you have to take all the braces out if more then one and repair the joint first. Bracing is done after the repairs.

Maybe better and full shot pics might help. You can see all of the bass but we can only see the parts that you show us.

[Thomas Erickson]

In the interim I have decided that it would be the correct thing to just keep the brace as the maker had envisioned . Its French after all .

IMO it is just a brace, and changing it would most likely be an improvement. Since it has to come out to repair the seam, you might as well update.

[Adrian Levi]

Here are a couple of pics. The centre join had a piece of epoxied wood in it up to the big brace as can be seen in the pics. The back sits perfectly on the ribs now after I took it off (before it was being pulled in all directions from the epoxy).
Now what route to take.... full center seam inlay ???
Due to massive peer pressure I will replace the back brace .
Any advice on how many braces the bass will need , Im guessing 3 or will sturdy patches along the centre seam be an option ...?

[Ken Smith]

Here are a couple of pics. The centre join had a piece of epoxied wood in it up to the big brace as can be seen in the pics. The back sits perfectly on the ribs now after I took it off (before it was being pulled in all directions from the epoxy).
Now what route to take.... full center seam inlay ???
Due to massive peer pressure I will replace the back brace .
Any advice on how many braces the bass will need , Im guessing 3 or will sturdy patches along the centre seam be an option ...?

Massive Peer pressure? I just gave you the advice based on seeing many French basses that were improved that way. One center brace, one lower and one upper usually and possible depending on the condition of the back and length, 2 upper ones. One at the bend and one at the blocks. The lower and mid/block brace to be shaped like a bassbar. The center is flat maybe 4-5" wide, 1/2" tall and the upper bend brace maybe 2" wide and beveled. Tastefully shaped, not lumber-like 2x4s.

The Center joint may need to be re-jointed and then, a strip placed in there to fill the gap. Also, how is the overhang of the Top on the bottom bouts over the Ribs? Overlaps or more flush like? If Flush, cut the ribs at the block and tuck them in slightly shorter. The lower corner blocks may need trimming under the Ribs as over time, the string pressure pulls the lower block forward bending the back at the bottom under that wide stair-step brace as well as twisting the corner blocks inwards. This is a common fault with old French basses and correction is not easy. The bass needs to be modified. Just like with blockless basses, if made with corner-cutting, money-saving techniques, it needs expensive corrections in restoration.

Just guessing here what you may need. ;)

[Adrian Levi]

Massive Peer pressure? I just gave you the advice based on seeing many French basses that were improved that way. One center brace, one lower and one upper usually and possible depending on the condition of the back and length, 2 upper ones. One at the bend and one at the blocks. The lower and mid/block brace to be shaped like a bassbar. The center is flat maybe 4-5" wide, 1/2" tall and the upper bend brace maybe 2" wide and beveled. Tastefully shaped, not lumber-like 2x4s.

The Center joint may need to be re-jointed and then, a strip placed in there to fill the gap. Also, how is the overhang of the Top on the bottom bouts over the Ribs? Overlaps or more flush like? If Flush, cut the ribs at the block and tuck them in slightly shorter. The lower corner blocks may need trimming under the Ribs as over time, the string pressure pulls the lower block forward bending the back at the bottom under that wide stair-step brace as well as twisting the corner blocks inwards. This is a common fault with old French basses and correction is not easy. The bass needs to be modified. Just like with blockless basses, if made with corner-cutting, money-saving techniques, it needs expensive corrections in restoration.

Just guessing here what you may need. ;)


Now thats interesting info ( the peer pressure is now at boiling point :D ) ....

When I sit the ribs on the back , the fit is good with approx 3-5mm overlap all round . Surprisingly with all the non original glues , cleats etc the bass seems to have regained its shape to a large extent . I will remove the middle bar and use it for the top repairs , there is a lot of wood to be had from it.
Ken when you talk about cutting the ribs at the 'block' to get a good plate fit are you talking about the end block ?

[Ken Smith]

Now thats interesting info ( the peer pressure is now at boiling point :D ) ....

When I sit the ribs on the back , the fit is good with approx 3-5mm overlap all round . Surprisingly with all the non original glues , cleats etc the bass seems to have regained its shape to a large extent . I will remove the middle bar and use it for the top repairs , there is a lot of wood to be had from it.
Ken when you talk about cutting the ribs at the 'block' to get a good plate fit are you talking about the end block ?

Yes, but only if needed. I have a Bass that needs that now as well as needing some trim fit at the corner blocks from twisting as well. The Top is inside the Ribs now sitting on the internal half-edging with is stepped outwards to overlap the ribs.

[Adrian Levi]

In this case where the back and top are off at the same time , which should go on first , and is it ever ok to have to push the ribs in a bit whilst gluing and clamping if they are a little out of position in a few places?

Ken also if the ribs get cut down at the end block , then surely the top overhang will differ slightly i.e , maybe more overhang in the middle of the lower bout than at the end block due to the top not being exactly shaped to the rib dimensions anymore ...

[Ken Smith]

In this case where the back and top are off at the same time , which should go on first , and is it ever ok to have to push the ribs in a bit whilst gluing and clamping if they are a little out of position in a few places?

Ken also if the ribs get cut down at the end block , then surely the top overhang will differ slightly i.e , maybe more overhang in the middle of the lower bout than at the end block due to the top not being exactly shaped to the rib dimensions anymore ...

You tool both the Top and back off at the same time? Good luck with that. Generally I see the Top done first and then put on the Ribs and then the back off and done. If both off, get the Top done and Back on first and see if or how much you have to tuck in the Ribs at the block for even overhang.

If the Back is less work, then do that first since you have a mess to deal with either way from taking it all apart at once. Good luck!

[Adrian Levi]

You tool both the Top and back off at the same time? Good luck with that. Generally I see the Top done first and then put on the Ribs and then the back off and done. If both off, get the Top done and Back on first and see if or how much you have to tuck in the Ribs at the block for even overhang.

If the Back is less work, then do that first since you have a mess to deal with either way from taking it all apart at once. Good luck!


Jeeez , now I feel like a war criminal...

Maybe I never had an option but to take the back off !!!

Firstly the bass came with the top off and in 3 pieces due to the fact that the back was glued on with a &^%&^ load of epoxy . Whoever epoxied the back made sure that the ribs were forced in by a good few mm all round , making sure that the opposing pressure on the top would pull it apart .
So what was I to do , rebuild the top to accommodate a very unique and asymmetrical rib shape and then once that was glued on remove the back and rebuild the back to mirror the top ??
My intentions are simply to learn as much as possible about repairing and maintaining basses.

[Ken Smith]

Jeeez , now I feel like a war criminal...

Maybe I never had an option but to take the back off !!!

Firstly the bass came with the top off and in 3 pieces due to the fact that the back was glued on with a &^%&^ load of epoxy . Whoever epoxied the back made sure that the ribs were forced in by a good few mm all round , making sure that the opposing pressure on the top would pull it apart .
So what was I to do , rebuild the top to accommodate a very unique and asymmetrical rib shape and then once that was glued on remove the back and rebuild the back to mirror the top ??
My intentions are simply to learn as much as possible about repairing and maintaining basses.

Thanks for clearing that up.. Good luck with the project.

[Arnold Schnitzer]

Here are a couple of pics. The centre join had a piece of epoxied wood in it up to the big brace as can be seen in the pics. The back sits perfectly on the ribs now after I took it off (before it was being pulled in all directions from the epoxy).
Now what route to take.... full center seam inlay ???
Due to massive peer pressure I will replace the back brace .
Any advice on how many braces the bass will need , Im guessing 3 or will sturdy patches along the centre seam be an option ...?Adrian, you have a tricky repair ahead of you. If the back is wide enough to fit on the rib assembly with some margin (overhang), then you'll just need to fill the big gap in the lower part of the back. If the back needs widening, you may want to add a strip down the center. Either is a difficult job. If you are going to fill the existing gap, start by gluing several temporary braces across the gap, using them to hold it together and flatten the area while you fit a patch. These braces should be about 6" or so long, attached with reversible glue.

[Ken Smith]

Adrian, you have a tricky repair ahead of you. If the back is wide enough to fit on the rib assembly with some margin (overhang), then you'll just need to fill the big gap in the lower part of the back. If the back needs widening, you may want to add a strip down the center. Either is a difficult job. If you are going to fill the existing gap, start by gluing several temporary braces across the gap, using them to hold it together and flatten the area while you fit a patch. These braces should be about 6" or so long, attached with reversible glue.

Adrian, here are some examples of those temporary blocks used on the HART that Arnold restored..
http://www.kensmithbasses.com/doublebasses/hart/older-hart-images/bass-007.jpghttp://www.kensmithbasses.com/doublebasses/hart/older-hart-images/bass-006.jpghttp://www.kensmithbasses.com/doublebasses/hart/older-hart-images/bass-012.jpg

As you can see, the blocks were left in till after the crossbars were glued in and taken out only when.. Arnold? (you tell him..:))

[Adrian Levi]

Ok now what to do .... ?

The back fit is textbook ie a healthy amount of overhang all round . If I clamp the neck and end blocks to the back it maintains perfect symmetry so I believe that with an extra pair of helping hands I will get the fit correct without having to apply unnecessary distortion to the ribs.
The gap you see at the lower bout join was originally filled with some wood that I removed / the gap must have been man made to try and cover up for some damage or something / i.e it is not caused by shrinkage etc..

My question is do I refill the gap with wood as was or plane the gap to an even width and insert a strip like on the pic Ken posted .
Obviously cosmetically the latter is the proper option or ?

[Thomas Erickson]

I'd be inclined to re-joint the back and put a tapered strip in. Heck I'd probably use ebony or something! :rolleyes:

If the rest of the joint is already solid though, I guess you could inlay a slice into the gap - but it wouldn't look as nice and probably wouldn't be as solid long-term...

Basically I'd un-do everything and make the back perfect, then go from there. Since you have the top and back both off (right?), getting the back to be a nice perfect platform should be a lot more pleasant when you're putting things back together!

[Pino Cazzaniga]

Another way is to restore the top, then to make a template from it, maybe with thick plywood, then to glue the ribs on the template, only at blocks, temporary, then to decide what to do with the back, then to restore the back and glue it on the ribs, then to remove the template and glue the top. this way you can widen (or not) the back to follow the top shape. Also, the top-ribs joint is usually flat, while the back is bent.
My two cents, good luck.

[Matthew Tucker]

Usually once I take the top or back off, I keep the corners and blocks into position with a sheet of 4mm plywood. Cheap and simple. A small screw through the ply into the face of each block holds everything in position until i'm ready to replace.

Jointing a back with a bend or curve in it, is tricky. You can't just line them up on a tabletop. I note Arnold's temp block method which I 'll have to try. Last one I did, I built a pair of cradles to which I tack-glued the back pieces. This allowed me to align them on a flat surface, plane the edges and clamp the insert simply and accurately.

http://farm3.static.flickr.com/2599/4027394421_371cedd1e7.jpg

http://farm3.static.flickr.com/2568/4111353934_9ea41ce11c.jpg
http://farm3.static.flickr.com/2781/4110589573_4c4912e85a.jpg
http://farm3.static.flickr.com/2624/4110590085_eb763dc390.jpg

... and before anyone says anything about the alignment of the upper bout in the next picture, this was just the two sides pushed up against each other before glueing!

http://farm3.static.flickr.com/2739/4111354766_5ca8513221.jpg

http://farm3.static.flickr.com/2540/4111355074_ebd02ed4e9.jpg

[Ken Smith]

Matt, the work looks good.

Adrien, being that you can see the bass in person and we can't you have to decide the method of attack. Personally, I think a complete re-joint of the center with an even strip in the middle would look best and be the safest way to go. This way, you can trust the joint you made. If not and it fails again where you didn't touch it, then it's back to square one again. Do it once and do it good.

[Adrian Levi]

[QUOTE=Matthew Tucker;21282]Usually once I take the top or back off, I keep the corners and blocks into position with a sheet of 4mm plywood. Cheap and simple. A small screw through the ply into the face of each block holds everything in position until i'm ready to replace.

Jointing a back with a bend or curve in it, is tricky. You can't just line them up on a tabletop. I note Arnold's temp block method which I 'll have to try. Last one I did, I built a pair of cradles to which I tack-glued the back pieces. This allowed me to align them on a flat surface, plane the edges and clamp the insert simply and accurately.

Nice work !!! Thanks for the pics :)

PS-is Warne really making a comeback ?

[Adrian Levi]

Matt, the work looks good.

Adrien, being that you can see the bass in person and we can't you have to decide the method of attack. Personally, I think a complete re-joint of the center with an even strip in the middle would look best and be the safest way to go. This way, you can trust the joint you made. If not and it fails again where you didn't touch it, then it's back to square one again. Do it once and do it good.

Thats exactly what Ill do , a complete re-joint .... Ill start early January and post pics etc :)

[Matthew Tucker]

PS-is Warne really making a comeback ?

dunno. I'm not into footy much.

[Adrian Levi]

dunno. I'm not into footy much.

Matthew please tell me that you're kidding :confused:
An Ozzy that equates Shane Warne with footy :eek:

( I guess that this qualifies as a total thread derail ):o

[Thomas Erickson]

now that you have this to my level- I will post

Hello, you'te on basstalk with Bo and Pluck the Fidler brothers--don't play like my brotha and don't play like my brotha.

Hi, This is Tootie from Fruitland. My bass is an old upright and it has a footy smell to it. Bo-Geeze, I don't know, why don't we pose the question to our listening audience- Pluck- good idea Bo, go ahead- okay- has anyone out there ever had their bass smell footyly?

That was ten years ago and no one since has ever heard of much less smelled of a footy bass, until today on the Ken Smith forum. Will Footy and Warne ever get back together, will Warne make a comeback-we hope so and we hope the best for Footy too.

Hey Wayne - I bet if you were interested in making a film about double bass repair that Tommy Chong would be willing to produce it... ;)

[Ken Smith]

now that you have this to my level- I will post

Hello, you'te on basstalk with Bo and Pluck the Fidler brothers--don't play like my brotha and don't play like my brotha.

Hi, This is Tootie from Fruitland. My bass is an old upright and it has a footy smell to it. Bo-Geeze, I don't know, why don't we pose the question to our listening audience- Pluck- good idea Bo, go ahead- okay- has anyone out there ever had their bass smell footyly?

That was ten years ago and no one since has ever heard of much less smelled of a footy bass, until today on the Ken Smith forum. Will Footy and Warne ever get back together, will Warne make a comeback-we hope so and we hope the best for Footy too.

OMG, Wayne, must you turn every hint into a complete Circus. Please tell me this is a rare occasion and you will stop the silliness.

Maybe I have to go back and clean all this up now. Someone PAY ME!!!!!:mad::mad::mad::mad::mad::mad:

[Anselm Hauke]

ken, it´s your forum, you are the boss.
but sometimes i think the forum (and maybe you too) would benefit if you could expand your comfort zone regarding humor a little bit.

[Ken Smith]

ken, it´s your forum, you are the boss.
but sometimes i think the forum (and maybe you too) would benefit if you could expand your comfort zone regarding humor a little bit.

Oh, I'm comfortable.. lol.. I just don't want the main topic to be buried by circus animals.

50/50 would be nice. Make a comment on topic and throw a joke in. Jokes alone are childish after awhile. Adrien is doing his best to bring basses back to life in an area that doesn't have people he can visit to help. This Forum is basically his life line. So, 50/50 I would say is a comfort zone.. for the most part..;)

[Anselm Hauke]

So, 50/50 I would say is a comfort zone.. for the most part..;)

i agree :)

[Adrian Levi]

BTW , whilst taking the back off and cleaning it up I found that by using cotton wool soaked in dark vinegar dissolved white wood glue , and very effectively as well .
Here is a pic of glue removal on the one rib of the bass that we are discussing that had a been doubled with veneer and Gorilla glue.
The vinegar also seems to lift stains/dirt.I'm not sure that it would be a good idea to leave the vinegar on for too long though in terms of possible wood damage ....

[Dave Martin]

Our 50/50 bonus
Puzzler of the week---what is or who is a footy? Is it something that Ken has, maybe Arnold has one. Would Ken need or want one? How much are they, maybe I'll get him one for Xmas. If he doesn't like it can he exchange it for something more hanty?
Though to most folks, 'Footy' is Australian Rules Football at our house we always refer to these (http://www.kohls.com/upgrade/webstore/product_page.jsp?PRODUCT%3C%3Eprd_id=8455248923814 77&pfx=pfx_shopcompare&cid=shopping3&mr:trackingCode=E52E6FB2-76B7-DE11-93DB-0019B9C043EB&mr:referralID=NA) as footies. Or these (http://www.pajamacity.com/Adult-Footed-Pajamas/products/103/)...

Ken would need to decide whether they're for him...

[Adrian Levi]

Still on topic with the bass in this thread , I am in need of some more advice if possible ...

I have started cleaning up the ribs which are in pretty good shape with the exception of the one lower bout that I cleaned up in part today.
I removed a veneer that was epoxied on by using steam to help loosen it.The
rib is now very weak. There is still epoxy residue on the rib which Ill remove when the rib is dry again.
Attached are a couple of before and after pics, there are a lot of cracks etc.

I've had to now clamp the rib with flat pieces of wood on the inside so that it keeps its original shape.
Any insight on the next step to saving the rib would be great ....?

[Matthew Tucker]

How has the original doubling repair failed?

[Adrian Levi]

How has the original doubling repair failed?

The original doubling was strong enough , but had holes cut in it to accept long glued pieces of wood . Also it was a cheap type plastic wood mix kind of thing, and in my opinion did not belong on the bass.If I put another real wood veneer onto the rib it would regain its strength but I was thinking of perhaps using thin willow or spruce strips with linen strips in between from lining to lining ?

[Pino Cazzaniga]

I prefer willow or poplar or spruce strips than veneer.
I would glue the linen strips a bit on the linings too, to prevent cracks at their inner edges.

[Matthew Tucker]

I think if you can be assured of a good glue joint them a veneer doubling would be strongest especially if the rib is badly damaged. So effectively you have a new rib but with the old rib becoming a decorative veneer itself. And if you're going to replace the linings then the doubling can go edge to edge.

But getting a good glue joint on such a large surfaces is tricky, it is much more practical to fit and clamp softwood strips and/or linen Ã* la Bollbach (http://jeffbollbach.com/JB%20II/Image%20Gallery/restoration1.htm)

[Thomas Erickson]

Japanese paper?

[Adrian Levi]

I think if you can be assured of a good glue joint them a veneer doubling would be strongest especially if the rib is badly damaged. So effectively you have a new rib but with the old rib becoming a decorative veneer itself. And if you're going to replace the linings then the doubling can go edge to edge.

But getting a good glue joint on such a large surfaces is tricky, it is much more practical to fit and clamp softwood strips and/or linen Ã* la Bollbach (http://jeffbollbach.com/JB%20II/Image%20Gallery/restoration1.htm)

Matthew , that link you sent was kind of what I had in mind , that repair looks
super stable.

[Matthew Tucker]

Stefano Sciascia told me the ribs of his cornerless bass (the one I copied) are lined completely with linen from end-to end. The bass still sounds beautiful.

[Adrian Levi]

Japanese paper?

Tell me more ???

I've seen brown cardboard box type paper being used before but have never been able to find out much about it .

[Adrian Levi]

Stefano Sciascia told me the ribs of his cornerless bass (the one I copied) are lined completely with linen from end-to end. The bass still sounds beautiful.

I've experimented with gluing linen into wood to see how much punishment it can take and found that it is incredibly strong. Seeing that it shrinks a bit after drying it seems to hold cracks together very nicely. The weight to area ratio also makes sense to me ,it weighs a fraction of what wood does and is simple to get near perfect gluing contact.

[Adrian Levi]

I've removed the fat brace from the back and what a nice piece of old spruce it is . It will come in super handy for the top repairs that are needed.

The back is in decent shape and Ill be inserting a centre strip throughout which means Ill need to remove a bit of back wood.
Im sticking to Kens ''do it right first time '' advice.

Now for yet another question or two ( if Im asking too much please tell me to shut up )!
How many back braces should this bass have ?And also is there an optimal positions for them ?
I've seen basses with 3 , 4 and 5 braces before ?

[Adrian Levi]

I've removed the fat brace from the back and what a nice piece of old spruce it is . It will come in super handy for the top repairs that are needed.

The back is in decent shape and Ill be inserting a centre strip throughout which means Ill need to remove a bit of back wood.
Im sticking to Kens ''do it right first time '' advice.

Now for yet another question or two ( if Im asking too much please tell me to shut up )!
How many back braces should this bass have ?And also is there an optimal positions for them ?
I've seen basses with 3 , 4 and 5 braces before ?

oooook , no bites on this one :mad::D

So now Ill try and be more direct .

'' Is the Venerable Arnold E. Schnitzer in the house ? "

What really interests me is the middle back brace seeing that it is directly coupled with the sound post .
Are there any thoughts on maybe using lighter wood to facilitate vibration to the back plate , or would heavier wood be better better for some reason , or is it just a simple matter of there being no definitives here ?

[Thomas Erickson]

Tell me more ???

I've seen brown cardboard box type paper being used before but have never been able to find out much about it .

Well, I don't know a lot about it either, but I've been meaning to track down some samples and whatnot. If anybody has looked into it or has a suggestion of what to look at/for specifically, I'd be happy to hear it - I have two basses with super thin ribs that need something done with them, and I plan to try this on one or both.

But basically there's a whole spectrum of high quality Japanese papers out there that people use for various art/craft purposes; a lot of them are made by hand (to some degree) and should be of conservation-type quality. The fiber used is very specific, high quality, single source and minimally processed, and the papers come in every thickness, texture etc. that you can imagine. As far as I know, this is where you want to look to find the strongest/lightest very best quality paper - and if it is like Japanese tools, I don't doubt it!

So in theory you should be able to find an ideal paper for this sort of purpose - it makes sense to me, I mean, after all what is paper but an extremely uniform manufactured wood product, yes?

[Matthew Tucker]

Aah ... easy questions I see :)

Why do you want the back to vibrate at all? just asking.

[Thomas Erickson]

Aah ... easy questions I see :)

Why do you want the back to vibrate at all? just asking.

Dynamat? :D

[Adrian Levi]

Well, I don't know a lot about it either, but I've been meaning to track down some samples and whatnot. If anybody has looked into it or has a suggestion of what to look at/for specifically, I'd be happy to hear it - I have two basses with super thin ribs that need something done with them, and I plan to try this on one or both.

But basically there's a whole spectrum of high quality Japanese papers out there that people use for various art/craft purposes; a lot of them are made by hand (to some degree) and should be of conservation-type quality. The fiber used is very specific, high quality, single source and minimally processed, and the papers come in every thickness, texture etc. that you can imagine. As far as I know, this is where you want to look to find the strongest/lightest very best quality paper - and if it is like Japanese tools, I don't doubt it!

So in theory you should be able to find an ideal paper for this sort of purpose - it makes sense to me, I mean, after all what is paper but an extremely uniform manufactured wood product, yes?

I must say that does sound interesting , Ill check out some art supply shops to see if they have and then maybe do a test or two .

[Adrian Levi]

Aah ... easy questions I see :)

Why do you want the back to vibrate at all? just asking.

Well Matt this is what interests me , should the back vibrate as much as possible or not ? Or does it really matter? Will my bass perform better if I fit a
middle brace of maple (heavy) or one of spruce...:confused:or once again does it really matter?

[Matthew Tucker]

Well that is the balancing act ... and where the art comes in i suppose. Whatever vibration is happening at the back of the instrument, that is energy that is NOT moving the front. So it robs the front of energy at certain frequencies and thus colours the sound and decay characteristics of the bass. I like to imagine the extremities; if the back was made of concrete the top would receive and emit all of the string energy, with a lot of sustain,but the sound might not be pleasing (it might - who knows?). On the other hand I imagine if the back were made of rubber and could freely vibrate it would dampen the movement of the front resulting in short sustain and dunno what tone. And that's not taking into account the structural necessities. Somewhere in the middle is right. As a broad generalisation, I think for arco, sustain is not so critical but darkness is, for pizz/jazz use sustain is more useful and the decay characteristics of the bass are more important. but it depends on the player too.

But with all that above, its still hard to know for sure what the effect of one or other change will be!

I would replace the brace with spruce as it was originally, probably a 4-5" centre brace, one across each bout to give a slight and even radius to the back if possible, and one at the bend if it needs it. Depending on the position of the bend, you may choose to put one brace near or on the bend for the upper bout.

Or you could get really funky and do a cross brace!

[Adrian Levi]

Well that is the balancing act ... and where the art comes in i suppose. Whatever vibration is happening at the back of the instrument, that is energy that is NOT moving the front. So it robs the front of energy at certain frequencies and thus colours the sound and decay characteristics of the bass. I like to imagine the extremities; if the back was made of concrete the top would receive and emit all of the string energy, with a lot of sustain,but the sound might not be pleasing (it might - who knows?). On the other hand I imagine if the back were made of rubber and could freely vibrate it would dampen the movement of the front resulting in short sustain and dunno what tone. And that's not taking into account the structural necessities. Somewhere in the middle is right. As a broad generalisation, I think for arco, sustain is not so critical but darkness is, for pizz/jazz use sustain is more useful and the decay characteristics of the bass are more important. but it depends on the player too.

But with all that above, its still hard to know for sure what the effect of one or other change will be!

I would replace the brace with spruce as it was originally, probably a 4-5" centre brace, one across each bout to give a slight and even radius to the back if possible, and one at the bend if it needs it. Depending on the position of the bend, you may choose to put one brace near or on the bend for the upper bout.

Or you could get really funky and do a cross brace!

Interesting thoughts there.
What is the deal with cross bracing ? I've always wondered about those basses with a single longitudinal brace .....

[Matthew Tucker]

Ask Ken McKay he's done it. I haven't.

[Ken Smith]

What a bunch of confusing opinions I see here.

Ok, one single brace is not good.

Depending on the bass, it's size, your climate and what tone you want you can go with just about anything that works but a single wide center brace like you just took out. Also, there is little advantage if any making the smaller center brace out of the wide one you just removed. If you can, do it for the enjoyment. In that case you will need one across the lower bout and upper bout on the average. I think 3 or 4 braces with two uppers is quite normal but that depends on the back itself. I have seen as few as 2 and as many as 5 on the back braces (or 1 in the case of French basses). Again, take a chance and do what looks good for you in your mind, the bass itself and the climate it will live in. The X-system is a choice in some cases depending on all of the above as well and in that, there are a few ways to do the X. Two pieces with a lap joint, 3 pieces with no joint, one angled piece with a separate lower bar type cross angled or what ever the bass needs in your mind. Other than the center brace, the other braces should be shaped more like bassbars and not flat wide pieces, I think!


Have fun. The restorers that have repaired the most backs successfully will have the best advice in my opinion. Nothing is ever easy with a flatback. You have the birdseye view of the back in question to decide how much support it needs to work and how much to let it breathe.

I have had and played basses with just about every kind of back out there, well most of them. You don't know whats best without changing things and living with it for a decade each way. The back vibrating is not a problem. Even the scroll vibrates. My Gilkes was as loud from the back as it was in front. The Sound post will make it vibrate but the top should float more than the back. Don't get too technical here in the mind. Repair it sensibly and go play the bass, That's part of the recovery, the playing in of a restored bass.

[Matthew Tucker]

Wayne, how on earth can X braces be an easy way out?

[Matthew Tucker]

seriously, less cutting, less thought, less everything, less clamping, less coverage of the middle seam, lesser number of pieces, less measuring,less amount of wood crossing the middle seam, less confusion- less time, less creativity, shall I continue? less balance and support of structure- less lipstick!

http://farm4.static.flickr.com/3209/2952795669_1dc73f76dc.jpg

Would you be happier with far simpler lattice bracing perhaps??

[Adrian Levi]

[QUOTE=Ken Smith;21709]What a bunch of confusing opinions I see here.

[QUOTE]Have fun. The restorers that have repaired the most backs successfully will have the best advice in my opinion. Nothing is ever easy with a flatback. You have the birdseye view of the back in question to decide how much support it needs to work and how much to let it breathe.

I like the fun part , and the excitement of the unknown / Im going with the 3 braces.

[Arnold Schnitzer]

http://farm4.static.flickr.com/3209/2952795669_1dc73f76dc.jpg

Would you be happier with far simpler lattice bracing perhaps??

Nice! But just a bit too much glue for my taste...

Adrian, I agree with the 3 brace technique. Keep them away from the linings, and feather the ends after the glue is cured. Glue it all up when climate conditions in your shop are toward the dry side. Use a caul on the outside of the back under each brace as you glue up. Good luck!

[Ken Smith]

[QUOTE I like the fun part , and the excitement of the unknown / Im going with the 3 braces.[/QUOTE]

My Mougenot is about as French as it gets as far as the Tradition goes. Full sized Vuillaume model (7/8th by our standards), flatback and it had a single wide center brace. Like my Hart bass, the back never cracked but opened up in the center seam, 3/4's its length, both basses. The Hart has a very stiff & strong back so it got a center and lower brace only and studs and linen I recall at the angle break ( I will have to look inside to make sure). The Mougenot is still on Jeff's bench getting the C-extension but I think we agreed on 3 or 4 braces, 1 or 2 upper (I will have to look as I forgot what we discussed). French basses usually bend gradually from the upper corner block and never a direct angle break. Both basses got an added center strip most of the way up which is a good thing because it shows that rather then the back splitting over time, the center just opened which looks much better repaired than a bunch of back splits.

So, depending on the length of the back, just the upper bout in the center would be fine unless the back is thin and needs more support. Like I said in my last post, you have the best view of this and must decide what it needs.

[Adrian Levi]

The ribs are now as clean as I'm going to get them without doing more damage to the damage.It seems as if the bass was about 50% wood and 50% epoxy.
The one lower bout is the only one left to reinforce . The other lower bout with the repairs was less than 1 mm in places and still needs the back edging to be replaced.
Now that the two pieces of back are flattened and ready to plane for an insert I'm not quite sure how to figure the exact size that the insert should be.
The back has shrunk a fair amount and to compensate the ribs were force epoxied in. The freed rib structure now spans about 20 mm more in its relaxed state.
Is it a matter now of lying the rib structure on top of the back to measure the space needed for insert ?
Or is it better to measure the back against the top for size ....?

[Ken Smith]

Looks good. I would suggest fitting the Top first since it is the least flexible part and prone to cracking. The Back can be widened as needed but dry fit and estimate it first before making the center spline/insert.

[Adrian Levi]

Looks good. I would suggest fitting the Top first since it is the least flexible part and prone to cracking. The Back can be widened as needed but dry fit and estimate it first before making the center spline/insert.

That makes total sense and I just sat the top on the rib assembly and it is a perfect fit :) .I was worried that I may have to cut the ribs down to accommodate the top.

[Thomas Erickson]

That bottom block looks like a real thing of beauty...

[Adrian Levi]

I have just started the top repair with a bass bar patch as the crack was really jagged and totally messy. Ill leave the final shaping of the inlay for when the bar is ready to shape.
The ROUGH linen patches are just for crack support until cleating.

My question is as follows - in the pic there is a chalked cross a few inches below bridge position and for some reason the top has sunk in just a bit over there . I thought this normally happened directly under the bridge feet but the top is nicely rounded where the bridge feet should sit.
Should I try and fit the bass bar over the slightly raised area or is it better to
try and heat press it out in a mould even though it is over a small and pretty thickly wooded area ?

[Ken Smith]

I have just started the top repair with a bass bar patch as the crack was really jagged and totally messy. Ill leave the final shaping of the inlay for when the bar is ready to shape.
The ROUGH linen patches are just for crack support until cleating.

My question is as follows - in the pic there is a chalked cross a few inches below bridge position and for some reason the top has sunk in just a bit over there . I thought this normally happened directly under the bridge feet but the top is nicely rounded where the bridge feet should sit.
Should I try and fit the bass bar over the slightly raised area or is it better to
try and heat press it out in a mould even though it is over a small and pretty thickly wooded area ?

Press it out flat and do it right.

[Adrian Levi]

Press it out flat and do it right.

Ken whats this obsession of yours to always do things right ? ;)

[Ken Smith]

Ken whats this obsession of yours to always do things right ? ;)
None, it's my advice to your question. Once opened, do the Top completely. Don't do a bass bar over a depressed top. The purpose of a restoration is to restore. It's your bass so do as you wish.

[Adrian Levi]

None, it's my advice to your question. Once opened, do the Top completely. Don't do a bass bar over a depressed top. The purpose of a restoration is to restore. It's your bass so do as you wish.

LOL ,come on Ken that was a joke .... OF COURSE THAT IS GOOD ADVICE TO DO IT RIGHT FIRST TIME :D

I am making a mould for the top now

[Arnold Schnitzer]

Keep in mind that a thick top table will not press. You may have to thin it considerably, press it out, then patch the result. Quite an undertaking!

[Ken Smith]

LOL ,come on Ken that was a joke .... OF COURSE THAT IS GOOD ADVICE TO DO IT RIGHT FIRST TIME :D

I am making a mould for the top now

Oh, these are the jokes?.. Geeze, no one told me.. lol

Have fun with your Frenchie.. My Mougenot is done and I am meeting Jeff with the bass at Arnold's place for Lunch with the gang and maybe picking up my Claudot as well. Also, I am bringing my Jacquet up in the car. Wow, French toast for breakfast, gotta be.. Arnold, any French places for lunch in your area since it's mainly a non-Italian day?

Oh, not really. Bringing up the Sirletto for a seam gluing and looking over my Italian cornerless while my buddy Kevin gets an adjustment on her English Hawkes and picks up his tweaked Bollbach Lion bass. So.. it's international day.. yeahhh. Hey, French food never filled me up anyway.. ;)