Cello bass bar repair.

[Rick Gentry]

Howdy. 

Let's say that a fella found a cello with a missing bass bar. Let's say also that said bass bar was actually cut in two pieces, maybe to get the thing out so it wouldn't annoyingly rattle around. 

My plan is to cut the top off, and glue the bass bar back together with scabs on both sides. If a glued joint really is stronger than the wood itself, this would be perfect solution right? Scribing a new one seems a bit much when there are so many great adhesives to use.  

Then glue everything back and plug it into the Marshall. Ideas? 

   

[Pierre-Antoine Roiron]

Wow... considering you're going to unglue the top (though I'd rather cut the back off since it would be less visible afterwards), and that it's going to be a lot of work, I wonder why you hesitate to make a new bass bar. Making a new one would take very little time and maybe less time than finding a solution to glue back the two pieces. An that would be a cleaner repair.

[Pierre-Antoine Roiron]

More to this : while it's open, check the other bar too.

[Tim Mace]

I side w/ Pierre on this one but check w/ a viol family expert first. Don't scab..make a new one just like the old one.Go in from the back.

[Rick Gentry]

This isn't an expensive cello, probably Chinese. The reason I want to try to keep it running is that I installed expensive mechanical gears on it (Pegheds) and they are superglued in and work really great.
and the K&K transducer pick up sounds amazing through my pedal board. I am not afraid to start cutting on this particular instrument.

So the back will be easier to remove than the front?

[Tim Mace]

should be...plus if the top is in good shape it will remain so..is the K&K inside?And you shouldn't (hopefully)have to cut.It should be hide glue unless it's not.Hot knife and steam if hide glue should be a breeze.Slow and easy.Or if you really want to cut up a Chinese cello why not make a trap door in the back to access when you need to .

[Rick Gentry]

The pickup is superglued to the bridge (which I made since I didn't want to spend $40.00 on. The trap door thing is a brilliant idea, but I think there is more adventure and conquest in removing the back. The pickup has two 3/4" leads, and the wire wraps around the tailpiece with a little bit of foam between the 1/4" jack and the tailpiece. It is electrical taped on.

K&K said I could glue the pick up to the bridge, since their tape tends to come loose.

Looks like I get to buy a new tool. I have never owned a hot knife.

[Frank Ford]

The "other" bar?

Violin family instruments have bass bars - one to each instrument.

[Stuart Horsman]

Frank is correct. One bass bar-basically under bass foot of your bridge, and a soundpost under the treble foot (actually just behind the treble foot about 1/2 the dia. of the soundpost). Removing the back of the cello, instead of the top, will limit the sides warping out of shape before you put it back together. If you take your time, and work really slowly, a palette knife, and alcohol will disolve the glue and open the glue joint between the sides and back. Good Luck, Stuart

[Len Biglin]

For the sake of discussion , what would happen if you just put a soundpost under the bass side ? For the record , a friend of mine had the bass bar partially separate in his double bass and it cost him $2000 to have the back off and re-glue it , this was by an orchestra hot shot . Len

[Paul Hostetter]

Save for Frank's timely intervention, this thread is a trainwreck of non-information and/or simply bad advice.

You don't "cut" tops or backs off instruments like this—you remove them.

You don't ever use a hot knife or steam (!) to open a seam on a violin family instrument. Good grief!

You certainly don't remove a back unless it's absolutely necessary, and certainly not because it "will limit the sides warping out of shape before you put it back together." One would always opt to leave a back in place because the joint between the button and the heel needs to be preserved.

Moreover, when you do the only intelligent thing there is to do in a case like this—which is to make and fit a new bassbar—you need to have the top off the cello in order to fit and then clamp the new bar properly. You could never do that with the sides and the rest in the way. (If one couldn't get a top off and back on exactly right, it's probably wrong to even consider trying to remove it at all.)

You need that one soundpost to carry sound to the back, while the bassbar carries energy along the top. Its purpose is acoustic, not structural. A second soundpost would kill the instrument's response and would destabilize the other soundpost as well.

Viols and violins are not the same, structurally or tonally. Violins, violas and cellos are in the violin family; double-basses and a host of violin ancestors such as gambas are viols.

[Rick Gentry]

Let's remember that while this is an inexpensive import, it is still solid maple all around, and perhaps worth the effort. I would by no means try this on an instrument of real value. The hot knife thing was a disaster. It was so much easier to pull my Stanley knife a few times across the joint until it snapped. I sawed through all the blocks.

Here is the fitted bass bar and an improvised go-bar set up made from a leftover spindle. Everything stuck fine, and there it is in clamps. I used LMI glue. A little finish work and get the sound post in and we're done. I understand that some instruments are worth the extra effort and cost, but sometimes you just want to plug it in and keep it real. There are a lot of misperceptions of reality in the string section.

[Frank Ford]

Rick -

Looks like you have it under control - congrats.

I've been at this craft forever (it seems) and I still don't understand the hot knife thing. I do pry old hide glue joints apart, but I use a cold, regular thinned out putty knife.

Paul's comments are right ont he money - as usual.