French Bass full restoration

[Matthew Tucker]

The grain is parallel with the centre joint, and the bass bar is parallel with that. Dangerous, as you state!

[Ken Smith]

Originally Posted by wayne holmes

Thanks Brian-it's good to be back to my obsessive compulsive vicious cyclical track i have from the shop to the kitchen, to the computer---I just returned from playing one of those week-end concerts with 10hours of rehearsals, and the concert all packed into 2 days, I feel like I just completed an all day one-man hog-killing-----don't care if I ever again leave my double bass triagle. Thanks Ken for taking me back- I'll try to behave myself-

Matthew, If you do remove the bar and, as Arnold says, tweak the graduation- careful to not overdo it on the amount of wood that you remove. Now, how would I know that one can overdo it?

I would be interested in hearing how others protect the top from being damaged while doing the graduation or while removing a bar- As I think I mentioned before-I tape the entire finish side of the top with a layer of painters tape and then on top of that a layer of duct tape-then clamp the top at each end in a mould made with plaster for the particular top that I am working on.
It is easy to cause a crack when the wood is only a few MMs thick and some of it is old, dry and even a little brittle.

Wayne, maybe we should ask Matt to post the graduations here penciling them on the top so we can see what's what as well as the measurements of the Top in length and bout widths. What might work for one bass may not for another. The strength of the wood, condition, width, length all come into account here. When my Mougenot was opened I asked Jeff Bollbach if the Top needed any correcting as it did seem thick to me, especially from the outer F-hole edges. He replied it was fine and for a Bass this size, the thicknesses are good.

It is easy to take away wood. It is impossible to put the same wood back. Mane of the basses I have had in restoration over the years needed some breast patching to put wood back in from over re-graduating. Less of the basses I put thru shops to restore needed re-graduating or thinning as some call it.

If the bass is left thick (who is to really say if?), then no harm will be done to the bass. If thinned too much, the Top can cave in and crack, needing a huge restoration of re-shaping, crack repairs and breast patches. All because of someones over zealous so called corrections.

Maybe it's like a hair cut. Cut is as short as you like but leave the ears..

Funny thing about that (soory Matt for the de-rail) when I've gone for a hair cut at the mall. They ask if I wanna request anyone (for a small fee), and I say, "someone who's done it before".. lol

[Matthew Tucker]

Originally Posted by Ken Smith

Wayne, maybe we should ask Matt to post the graduations here ...

Er, ask all you like, but I'm not going to do THAT! I don't mind feedback at all, and I like discussing different approaches and thoughts on this sort of job, but it certainly won't be a restoration by committee!!

[Arnold Schnitzer]

Originally Posted by wayne holmes

I would be interested in hearing how others protect the top from being damaged while doing the graduation or while removing a bar- As I think I mentioned before-I tape the entire finish side of the top with a layer of painters tape and then on top of that a layer of duct tape-then clamp the top at each end in a mould made with plaster for the particular top that I am working on.
It is easy to cause a crack when the wood is only a few MMs thick and some of it is old, dry and even a little brittle.

I simply suspend the top upside-down in a perimeter frame. No tape, no "protection" whatsoever. I've yet to crack a top working this way. Sharp tools require no bearing down onto the surface. Of course, if you are working on an old bass with existing cracks, they need to first be adequately glued up, otherwise you could re-open them.

[Thomas Erickson]

On the subject of "dangerous" bass bars -

If, as in this case, a grain-parallel bar has yet to encourage a crack, is there really much justification for assuming that it will in the future, left as is? I mean sure, it makes sense to place a new bar across the grain, but I'm not seeing a real reason to replace an otherwise sound bar for this reason.

[Matthew Tucker]

Well if the top is overly thick under the bar, and/or the bar is overly heavy and stiff, then you will get a strong top a that spot, no matter what orientation the grain. But this is not necessarily a recipe for a responsive top and optimum sound. Also, this top was NOT intact - as you can see from the earlier pics it was seriously cracked in at least a dozen places; perhaps if the top was more flexible (thickness, arching shape, bar shape) it would not have cracked in that way. Perhaps the strength of the top around the bar itself encouraged cracks to form elsewhere? Perhaps, perhaps not ... who knows? All I know for sure is that the top is quite a bit heavier and less flexible than usual, and the bass bar is also very hefty and stiff. The original bar is intact, sure, but there's no evidence that it is "otherwise sound" if you measure that by how well it performs. So its a matter of using intuition to decide how to achieve the right balance of flex and strength.

@wayne - I think if you are making a plaster mould for each top you work on you must have a very big workshop and be built like a lumberjack! I've never needed to make a full top plaster mould - i'd be interested to see some pics of your setup.

I just have the top sitting in an MDF cutout cradle with no sharp edges and clamped in various ways. I don't use any protection on the top either, the MDF is softer than the wood and varnish, but if I feel the top needs any special support I'll use a smallish sandbag underneath. I'd really hesitate to use any kind of tape on the finish - even painter's tape - imagine the feeling you'd get if the solvents in the adhesive reacted with the varnish and the finish came off with the tape No thanks.

[Matthew Tucker]

On the weekend I bit the bullet and decided, after a chat with the owner, to remove the bass bar. I had some assistance from my nephew Luke who has helped me on some of my other builds.



We managed to recuperate some of the original bar to use as repair wood as the timber matches the top in colour and grain width.



After removal the top weighs 1665g.`

[Matthew Tucker]

While this was going on I started on making some purfling for the corner repairs.



I discovered that the original purfling is made of a pinkish wood, not white. I'm guessing this is some kind of fruit wood like pear or cherry, but not sure what. It's quite hard. I wonder if ID-ing this might help narrow down the bass's origin?

I had to hunt through my pile to find something that might match.



The strips are planed down with my large smoother



then taken down to the final thickness with my new HNT Gordon smoother with the blade setup as a scraper.





I have made a special jig for bending the purfling to roughly the right shape. sort of a mini fox-bender. I use a heat-gun for heat.



I've tried both PVA and hide glue; in the end, for this pre-bent stuff, the hide glue worked better.





After the glue is dry I cut the bent laminate into strips



neat, huh?

[Thomas Erickson]

Nice jig.

Do you heat the strips first and then put them in, or apply heat while bending? It looks like they're dry, right?