cracks in vintage ukes

I'm curious about how quick cracks can occur in vintage ukes when they're handled properly? And how does the cracking process occur - a single "break" or slowly over time? Recently, one of my 30's Favilla ukes developed a serious crack (i.e. all the way through) on the sound board. Can't remember if it had a small crack before but I don't think that it had a large crack. The fly in the ointment is humidity. I live in a fairly humid place in spring and summer, driest in fall and intermediate in winter. When I keep my ukes in hard cases I have a humidifier in the case but when I have them on stands (i.e., my regular players, all old vintage ukes) they're not humidified. OTOH the humidity changes aren't rapid and never really low (Georgia, USA). So under these conditions can a crack happen rapidly under the conditions that I've described or did this one just worsen for some reason. I have had the uke for about a month and it came from the midwest so it probably went from lower to higher humidity. TIA, g2

Wood is a curious thing so you will probably never know the answer to this for certain.

One scenario that is plausible is that the top crack was right on the verge of splitting deeper and when the uke moved to a different environment it began to rehumidify unevenly so a brace expanded before the top and popped the crack. There are dozens of other possible scenarios.

Also, if you keep ukes out on stands keep in mind that it is not the humidity outdoors that matters, it is the humidity in your home. If your house is well sealed and your central HVAC is sized properly your indoor humidity probably runs around 1/3 to 1/2 the outdoor humidity in summer and winter and a bit higher than that during spring and fall. It's counter-intuitive, but if your HVAC is under-sized humidity will be even lower, and if it is over-sized the humidity will be higher. In fact, when some people have their HVAC replaced they let a salesman talk them into a grossly oversized unit, then they wonder why they have mildew problems later. If the unit is too large it will cool the house too rapidly and not run long enough to keep the humidity down.

John

Thanks John, that's great info. We don't use the air conditioning that much, so I don't think that it's a home humidity problem but definitely something to think about. And there definitely wasn't any great change in environmental conditions. The uke is mahogany btw. I"m wondering if I shouldn't keep these old Martin ukes on stands but in hard cases with humidifiers which makes them less accessible but perhaps in safer conditions. That would be a bummer. I've seen videos of other folks with old Martins and their all on hangers so I'm a bit perplexed by this.

Hi Gary:

I think the thing to do is to buy a room hygrometer. I got mine at Radio Shack. I think it cost around $10.00. They are not terribly accurate, but 5% give or take should be accurate enough. If you discover that the RH where you keep your ukes falls below a safe range, you can get a humidifier, or just keep them humidified in their cases. Yes, I've seen those videos, too. Don't know what to make of them, but I do know that I live in an area of the world where humidification is a necessity.

As John points out, heating systems and air conditioners have a tremendous affect on the RH in your home. Did you recently turn the heat on? What kind of heating system do you have? A boiler isn't as dry as a furnace or electric heat.

Wood moves, it expands and contracts. Because it's glued together, it can only contract so much before it cracks. We assume that instruments are glued up at around 50% RH, which is why it is recommended that you maintain that level in storage. We also assume that the wood itself has been cured before it is used. Can we rely on these assumptions regarding vintage instruments? Or those instruments made overseas in humid climates? I'm pretty risk averse.

garyg said:

I'm curious about how quick cracks can occur in vintage ukes when they're handled properly? And how does the cracking process occur - a single "break" or slowly over time? Recently, one of my 30's Favilla ukes developed a serious crack (i.e. all the way through) on the sound board. Can't remember if it had a small crack before but I don't think that it had a large crack. The fly in the ointment is humidity. I live in a fairly humid place in spring and summer, driest in fall and intermediate in winter. When I keep my ukes in hard cases I have a humidifier in the case but when I have them on stands (i.e., my regular players, all old vintage ukes) they're not humidified. OTOH the humidity changes aren't rapid and never really low (Georgia, USA). So under these conditions can a crack happen rapidly under the conditions that I've described or did this one just worsen for some reason. I have had the uke for about a month and it came from the midwest so it probably went from lower to higher humidity. TIA, g2

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As other users have of course added, it would be most likely that the dryer humidity or quick succession of humid to arid would bring on something like that. The best solution of course would be a humidifier and to keep it in a case. Following that - containing the climate of the display (E.G ~ a glass display case) would greatly help to condition the ukulele to a relative humidity range rather than it being out in the open. Hope that helps a bit .... though you probably could have guessed or known as much!

Thanks folks, Howard I'll get a hygrometer, as Pua suggests, maybe I should just put my stands away and keep everything in humidified cases, but I do love just being able to pick up a uke. I've noticed that the crack has gone back to being minor so it likely was something about transport conditions although I'm always very careful about that. mahalo everyone, g2

I used to live in the Richmond Virginia area and wouldn't even think of humidifying anything from late May thru the 1st of December, and then much of December the temperture could easily be in the mid 50's low 60's. Could you be over humidifying?

I'm in Michigan now, and the hygrometer is still reading 47% inside, but it does get very dry here in the middle of winter.

Putting your pretty ukes into hiding is a shame.

I came up with a solution that works well, perhaps you can make one for yourself (having me make one and shipping to Georgia is possible, but maybe not too practical).

Three ukuleles fit inside and are hung by a small leather strap from the top. The plexi sides and front are not completely sealed, thus allowing the space to breath. The front doors slide to open. A standard case humidifier is placed at the bottom to keep the humidity consistent. Good luck with it.

Keep in mind that one thing a case (or a nice enclosed display case) offers that a stand or hanging on the wall doesn't is it mitigates rapid changes in humidity. Cases don't seal tightly but they do slow down the movement of air and thus the rate at which humidity (or temperature) change.

Humidity control is a very interesting subject to me. In the piano rebuilding business, we discussed this issue all the time. I suspect that ukuleles are not that different from piano soundboards. The wood is dried to the accepted moisture content before assembly. Then, no matter what we do, the wood swells and contracts over and over again, continually for as long as it's still recognizable as wood, splinters, or sawdust. Add water and the wood swells, add dry heat and it will shrink.

The conscientious among us control the humidity the best we can. What we're doing is tempering the changes in the extra-cellular moisture in the wood. But the intra-cellular moisture will continue to leave the cells of the wood continually throughout your instrument's lifetime. This is why we will always find cracks in vintage instruments. Always. Your Favilla, lovingly kept in a controlled environment will, over the course of eighty years of existence still lose the moisture in the cells of the wood. When enough moisture leaves the cells of the wood, it will crack. I'll bet if you took a piece of solid hardwood off the deck of the Titanic (plenty humid), and let it dry, it would crumble between your fingers.

This doesn't mean controlling the environment isn't a good idea. Maintaining an acceptable humidity level in and around your ukulele will, as I said, temper the changes in humidity. These changes in environment accelerate the loss of the woods natural moisture. So, taking good care of your instrument does lengthen its lifetime. And really, eighty years is a good, long life for a thin piece of dead wood.

One thing you might find interesting: Many years ago I was sent a piano from Florida that had "suddenly" developed a crack in the soundboard. The day it arrived in Chicago, it had one visible crack. (there were a couple others under the plate, where you couldn't see them) A week later there were dozens, and the first one was more than an eighth of an inch wide! All the Florida humidity was quickly leaving that hundred old wood. All those decades near the ocean, the instrument was kept humidified, but the wood was shrinking the whole time. I mailed pics (no email or digital photos then) to the customer and frightened him terribly. We had to mechanically dry the soundboard before we could repair it. And, I'm sure there were at least a hundred cracks of various sizes. But, the repairs made it beautiful again and it sounded great. So, the cracks weren't the end of the world.

So too, with your ukulele, the crack isn't really a big deal. I doubt it sounded any different the day after the crack was discovered. It can be repaired. What effects the sound is the gradual, slight shrinking and warping that has been going on all along. But, whether you decide to have it repaired or not, I suggest you keep your uke in Georgia. If you take it to Alaska for vacation, you may not recognize it when you get back.