early warning signs!

[John Bertotti]

Well I expected such a thing would eventually happen. I just noticed the beginnings of two cracks on the bowl but not at a join. In the middle of the ribs. One on the upper side and the second much smaller skips a rib and is on the upper back. Neither is right on the rib that makes the transitions from the sudo side to the back. I hope you followed that. I am curious what to do. I haven't learned enough to repair these early cracks myself yet and haven't the resources for a restoration. I don't want it to worsen should I stop playing it for the time being? They are small enough in width that only if you were anal retentive would you notice. It hasn't taken any abuse I am fairly sure it is just wear the same area is a bit wore of its finish. I imagine I could get it restored by a capable luthier but would be instrument-less. My plan was to buy another first then save and fix this one up appropriately. Any suggestions welcomed. I posted this hear because of this groups experience with the bowlbacks they had fixed up. I will link it to the builders section also. Thanks all John http://www.mandolincafe.net/iB_html/non-cgi/emoticons/sad.gif

By the way it get played up to or more than four hours a night on average. So I have been working it out. I have three instruments in the works myself. With my travel getting to them is tough I imagine now I have to make time and get them done. To bad they are all carve top instruments. At least it isn't to late to make them oval holes. Thank John

[vkioulaphides]

To my understanding, John, merely playing the instrument should not have any adverse effects on the bowl. Obviously, however, you may need to put it aside for it to be repaired. Minor repairs may be easy to pull off; major, full bowl reconstruction is an ENORMOUS job, both in work-hours and (consequently) in cost.

[Luthier]

John, You may try to put some kind of moisture source in just to get the crack together and glued. #The problem though is it may dry out and split somewhere else. #Where was it made?

Don

[Jim Garber]

Do these cracks actually move when you put slight figner pressure on them. They may be just finish cracks (hairlines), but the concern is that they are the starting of actual splits in the wood. These could have been caused by any changes in humidity and/or temperature.

For one thing, most of us live in climates where there are drastic changes in temperature and humidity from the summer months to the winter months. For sure you will need to get some sort of humifier for your case. Even a small sponge in the case slightly moistened would do it for the high dryness of winter heating.

As to the cracks: I would try to get someone competent to look at it and give you advice. It is very difficult to figure out what to do witghout havign the instrument in hand.

IMHO it doesn't sound horrible right now and I am sure that you can continue to play without the mandolin imploding. But I would have it checked out if you are concerned.

This is the joy of vintage instruments.

Jim

[grsnovi]

I don't recall what your mandolin looks like. Are these "cracks" separation along the grain? or are they "cracks" across the grain? What is the wood of your back? My Vega has a fairly high rib count and the rosewood ribs are separated by very thin strips of holly. I recall that at least one of these (rib joins) was repaired inside the bowl with a paper/glue patch. Externally you see a finish flaw along this join but it has been stable for as long as I've had the instrument (35 years).

[John Bertotti]

It is a 1911 Vega so I am assuming it was made in Boston. It is a fantastic instrument with virtually no ornamentation. I think the sound is exceptional and what a difference standing up makes. The whole instrument comes alive.
Keep in mind these are not cracks all the way through the rib. The are just on the surface not real deep yet. From my experience these will grow over time and I wish there was a way to stop it before it is a huge problem. They are definitely with the grain and do not flex but are in the wood. Thanks John

[Bob A]

MOnitoring humidity and keeping things at 40-50% should help. If you press your lips to the crack and suck, you should be able to determine whether air passes thru the crack. If not, don't worry. If there is a crack thru the instrument, I suspect a luthier would first humidify the instrument to approximate the edges, then work some glue in by applying it to the surface near the crack and rubbing it back and forth across the crack; then wipe the residue off carefully with a slightly damp cloth. then use masking tape to hold things together overnight.

I have a bowlback with a couple minor separations between ribs, and I'm not particularly worried. I will eventually get it off to the repairman; it should be an easy fix, I'm told.

When cracks develop in small aircraft, the fix is to drill a tiny hole at the ends of the crack, which stops the progression of the crack thru the material. I don't think this is proper for bowlbacks, but the theory should apply. Since the stresses induced in the wood are presumably due to shrinkage, humidification ought to slow things down, and eventual gluing will resolve the issue.

[John Bertotti]

I can with all certainty say this instrument has been in a climate floating between 70 to 76 degrees F and 47 to 55 % RH. I track my house real close. The problem will come in winter trying to keep the humidity up. It will usually drop to 35 to 37 % and I won't have that happening this year. I also tried the lip to the crack test and there is no ait flow. These are very superficial. I am going totry ans get some pictures of it. Thanks all. John
Where did sunglass smily go?

[John Bertotti]

here is the small crack it follows one of the dark grain lines just right of center. Tricky bugger to photograph.

[John Bertotti]

Here is the longer crack. This one was really hard to photograph. Had to use macro for both and hold them right under a light. Camera in on mandolin in the other. Thanks all john

[Luthier]

If you press your lips to the crack and suck, you should be able to determine whether air passes thru the crack. If not, don't worry.

I would be careful not to do this in a crowd. I am not quite sure if they would understand unless you had a really great explanation to back it up. You could also shine a light through and sight through the soundhole for any evidence of a split all the way through the rib.

Don

[Martin Jonas]

You could also shine a light through and sight through the soundhole for any evidence of a split all the way through the rib.
Won't work on most bowlbacks -- they're lined on the inside with any of a variety of materials (thick oil paper seems to be the most common on vintage ones).

Martin