Is balsa wood good to use as lining?

[newmando7]

Hello all,

I am just curious if Balsa wood is good for lining and what problems might I have if that is what I use.From what I gather the only thing the lining does is hold the plate to the rim,does it have any other use?

[sunburst]

Holding the plates to the rim is all the lining does. I don't see why Balsa wouldn't work, it's not very strong, but strong enough is strong enough. Linings seldom fail in use.

[Bill Snyder]

The balsa might work ok, but if it is a good choice why do we not see it used by luthiers? It bends with almost no effort.
I have used basswood for solid linings. It bends easily enough and I can get it at the local hobby shop.

[testore]

I like basswood too. Wouldn't balsa be a little to muchlike a sponge? IfI had to useit I'd definately size them before I would expect glue to be able to work after just one application. I size my linings anyway, can't imagine how much balsa would soak up.

[Dennis Russell]

Good Day: I have used ice cream sticks very succesfuly, I also have used it on violin repairs where the kerfing was damaged and had to be removed, I just cut the width in half, it bends very nicely when bent over a small hot pipe. Dennis in arizona

[Antlurz]

After having built lots of powered model airplanes in years past, I wouldn't think of using it.

Now, admittedly, there might be a different grade of balsa than I have ever seen, and some used IS a bit tougher stuff, but even if stuff twice that tough is available, and for the time and money invested, I personally wouldn't even consider it. I wouln't want to have to rebuild because I thought I was saving a bit of time and money by using it to begin with.

YMMV,and you might get away with it. You pays yer money and youse takes yer chances...

I'd sooner use plain old white pine.

Ron

[newmando7]

Thanks to all you great people for responding.I am considering alternatives as the linings from stew mac are tiny and my edges on my top plate are really thin which might be a problem with binding size so I was thinking of something solid and thick but still bendable.I would hate to go through all this effort on my #1 scratch built and have it explode on me.Thanks again for all the information you great people have.I`m fitting tone bars so my mind is wandering into the future steps.

[Gibson A5]

I like Ron have built with balsa for over 40 years and I would never even come close to thinking of using it for that. While it is stronger than most people think in compression, it sheds easly when pulled on side grain. The glue always holds good, but the wood breaks loose. Depending on the depth of the banding when cut, other than the blocks the only thing holding the plates on would be the balsa and not the rim. It might work fine, but I wouldn't chance it. It does work good for radio control model airplanes, I'm building another one out of balsa at this time myself.
Bill P.

[sunburst]

Ron and Bill, what failure would you expect from Balsa linings?
The strain that the strings apply to the plate joints is mostly sheer on the plate-to-lining glue joint, and also some amount of tension on the glue joints.

I've never used Balsa for anything (that I can remember), but it's hard to imagine that it would be so weak as to fail from sheer.

[Antlurz]

John... It would just pull itself apart. The old story is a good joint is always stronger that the wood underneath it. In this case there would be no doubt. It's no big deal to stick a fingernail a quarter of an inch deep in typical balsa.

The glue joint should hold to balsa just fine, but the integrity of the wood itself is composed mostly of air.

There should be density/weight charts available. They would tell a lot.

I think I'd compare it strengthwise to not a whole lot more than high density construction foam.It will crush terribly bad across the grain with virtually no force.

Ron

[Chris Baird]

Balsa is well known for its strength to weight ratio. There are some balsas which are harder than others and I'm quite sure it would work for linings assuming you used the denser stuff. I've heard talk of folks begginning to use it for violin plates. It holds together in model airplanes and they undergo quite a lot of stress flying around.

[Antlurz]

I'd make a considered guess the string tension on a mandolin would be at least twenty times higher than any stress encountered on a typical model airplane. And at any rate, a model plane is usually of a monocouque design, which imparts a terrific structure, strengthwise, and that load would be spread over several pieces. Ten pounds of pressure anywhere on a balsawood model plane is likely going to cause moderate to severe damage. I personally would use (seriously) laminated cereal box cardboard before I would use balsa.

...but that's just my guess. It might work.

Ron

[Gibson A5]

I have to agree with everything Ron said. A lot of balsa put together in a way to support each other is very strong for its weight, but bass wood would be a lot stronger and the weight difference isn't that much more for the bass wood. Why take a chance. I know there are prototype violins out there made almost all out of balas, but I do not think I'd ever build one that way. I think you would have to handel them very carefully. If you use hard balsa you could get it to work, but you would always be wondering if would come apart at the next strum. Just my thoughts.
Bill P.

[Antlurz]

Another factor to consider is string tension between a violin and a mandolin.

A violin is what? Maybe a third of the tension?

Ron

[Frank Ford]

I think balsa would be a poor choice for linings. Sure, it's available in nice little dimensional sizes and soft as cheese so it would be easy to form. And, it would hold a top or back on pretty much any mandolin. For that matter I suppose you could make the instrument without any lining at all.

But don't count on balsa to handle the knocks and bumps that instruments see in normal use. I, for one, have seen LOTS of broken linings. . .