How to Fix Warping Mandolin Top?

[bobskiebudgie]

Is there any way to fix a warping mandolin top? Please Help!

[bmac]

In what area is it warping and is it bulging outward or inward. Is it an oval hole or an f hole mando. What brand? (brand is important
as different brands are constructed differently, some solid, some plywood, some carved tops, some pressed.

Location of sinkage is important as it tells us if a brace or tone bar is involved. Braces or tone bars usually help hold the top in shape but if disconected they do very little. an accurate description and photos of the problem will allow knowledgable people to comment. Without more information it is anyone's guess.

[bobskiebudgie]

My mandolin has an oval hole and it is made by F De Mureda. It is warping inwards around the sound hole.

[sunburst]

It's probably distorting from string tension rather than warping. It's probably fixable, but someone would have to look at it in hand to know, and to know what it would take to fix it.

[bobskiebudgie]

If it was fixable how would I do it at home?

[Dave Weiss]

I had one like that. Probably not the recommended method, but I put a wet sponge into a zip-lock sandwich bag, left the top of the sandwich bag open (I made sure that the sponge didn't make direct contact with the wood) and stuffed it down in the hole. Then I put the whole mandolin into a garbage bag and sealed the top and left it that way for a month. It came out good as new. That was 2 years ago and the top hasn't re-sunk at all. I don't know what kind of mandolin you've got there or the value. I did it with an older Suzuki that was a family heirloom, I didn't have anything to lose so I took the chance... I let the grandkids play with it, it takes a lickin' and keeps on pickin'...

[bobskiebudgie]

I think mine is distorting as a strut inside has fallen off. How would I put the strut back on?

[sunburst]

It's probably fixable, but someone would have to look at it in hand to know, and to know what it would take to fix it.

I'm quoting myself here because this is the already-posted answer to your question. There is no way to say what it needs or how to fix it without looking it over.

[multidon]

Actually they are called braces. To fix that you would have to take off the back. That is usually smarter than trying to take off the top because the top is usually made of softer wood and it can distort, making it difficult to put back on. To do this job you need a stiff dull knife. Something like a palette knife from an art supply store, of Stew Mac sells special disassembly knives. Some manage to find a small scraper/putty knife at the hardware store that works for them. You also need a heat source for the blade. Some use the flame of an alcohol lamp. Once you have the blade heated up, try to work the blade into a weak spot in the glue seam. Work your way around a little at a time. The heat of the blade will cause the glue's holding power to fail. It doesn't have to be red hot; most glue fails at around 140-150 degrees F. Be especially careful around the end and neck blocks, there is more glue there. once the back is removed you locate the loose brace, scrape off the old glue, apply new glue (the palette knife is good for that, then clamp the brace back into position. Use cauls on either side of the clamp to prevent damage. When you are sure all is well, scrape off the old glue residue from the back and ribs, apply new glue, and clamp the back in place.

I answered you question because you asked how it would be done. That being said I do not recommend that someone attempt this unless they have experience. The potential for additional damage is great. Getting very cheap "yardsale specials" and practicing on those is a good way to gain experience. If the mandolin has any value, monetary or sentimental, I would take it to a qualified luthier to fix. He has the needed experience.

[Jim Garber]

Mr. Budgie: I think is is really necessary for you to reveal to the members here that your mandolin is a vintage Italian bowlback. I suppose De Mureda made flatt backs as well, bust most I have seen have been bolwbacks. Of course, I could be mistaken about this but if that is the case, I think that puts a slightly different slant for the solution to your problems. For instance, taking off the "back" is not as easy as on a flattop.

If this is not the case, then carry on as before and ignore my comments.

[multidon]

Jim- I am not familiar with Italian bowlbacks so I didn't recognize the maker. If I had known that's what it was I would have not given the advice I did. Now, to the OP- You REALLY need to find a luthier! Bowlbacks are darned difficult to work on and yours is definitely NOT a DIY!

[Tavy]

Don is correct that bowlbacks are not easy to work on, but they're not impossible either, though there aren't that many folks that have experience in the matter.

Here's the typical problem: all stringed instruments are a compromise between sound quality and strength, bowl backs are particularly lightly built, so if you do something you shouldn't (like put anything stronger than ultra-light strings on) they will fall apart! Even if you manage to avoid that trap, a 100 years plus of string pull will distort the body. If you think about what the strings are trying to do to the thing (basically fold the instrument in half), the pull will gradually split the ribs on the back apart, and compress the top downwards at the weakest point (either side of the sound hole). These distortions allow the neck to rotate forwards under string pull leaving you with an extra high action in addition to the structural issues. It's pretty common for braces to pop off the top under such stresses BTW.

The "cure" depends on how bad things have got - sometimes you may be able to:

* push the ribs back together and reglue.
* Straighten the top using a caul - Dave Hinds has a good discription here: http://www.mandolinluthier.com/Htable-warp-repair.htm
* Reglue the braces using a specially made clamp.

But.... that won't work for the more severe cases, in particular if there is a lot of crusty old glue around the split brace then it really needs to be removed, cleaned up, and reglued properly, which means removing the top. I also tend to worry that if one brace has parted with the top, then there may be more - it's usually pretty hard to tell actually even with a decent inspection mirror and flashlight. Sometimes the best/only way to assess the damage is to press firmly on the top directly above each end of each brace - the top should fell completely solid under pressure there, if there's any "give" then you have a problem with that brace.

Now for the good (bad) news Your instrument is almost worthless in the condition it's in (the bad part), and only of modest worth when fixed (still bad), so if you did want to try doing the work yourself you have very little to lose (the good bit.... no honestly it is...really). Fixing them up yourself can be fun and rewarding, but of course the most cost effective solution is to just buy a decent mandolin....

Your call.

HTH, John.

[Jim Garber]

John is correct and has done some beautiful work restoring old Italian bowlbacks. One other comment from my non-luthier experience. it is true of all mandolins and other stringed instruments that they are built under tension. In problematic bowlbacks i usually see either a cracked bowl or a cracked top. Something had to give somewhere if it was under stress.

[Jim Garber]

Mr. Budgie posted this pic on another thread. Looks like a basket case to me. of course there is no such thing as a dead mandolin as our friend Dave Hynds says.

[Tavy]

Mr. Budgie posted this pic on another thread. Looks like a basket case to me. of course there is no such thing as a dead mandolin as our friend Dave Hynds says.

Oh dear.... needs top removal at a minimum. Whether it's savable depends on whether the neck is still straight-ish....

[Lee]

Were you using extra light gauge strings, or was that possibly part of what caused the problem?

[Jim Garber]

Were you using extra light gauge strings, or was that possibly part of what caused the problem?

I highly doubt that this warpage was caused by anything anyone did recently but prob dates back a decade or more. I would guess that the OP found this at a flea market and wants to make it workable without much extra cost.

[bobskiebudgie]

That is EXACTLY what I want to do

[Jim Garber]

Check out Dave Hynd's site. here is a page about top warpage.

Also check out this Triage page for troubleshooting problems.

[bobskiebudgie]

I am only 12 and I am trying to restore this mandolin cheaply but i don't think I can do it. I really like old instruments and play the mandolin so I would like to get this fixed.

[Jim Garber]

bobskie: Thanks for letting us know that you are a kid. I hope you didn't think we were being mean or impatient with you.

Please let us know whether you are wanting to also learn how to fix instruments or just want something to play. I may have a mandolin I can send you for the price of shipping that would not need as much work as the one you have.

[bobskiebudgie]

That would be brilliant Jim! I would love that! It just depends on the postage from New York to Scotland.

[otterly2k]

Hey Bobskie-
Learning to repair and restore instruments is a really cool and fascinating thing to do. But it's not simple. And it's not necessarily cheap. It takes a lot of time and experience to learn to do well. An instrument like this can be a good place to start since it's already in such rough shape that you don't have a lot to lose from making mistakes. Because you WILL make mistakes... all new learners do and that's part of the process.

So (like Allen said in the thread you started about the tuners) ... if what you're after is to use this mando as a way to start learning repair skills... that's cool. Use some of the advice above and stuff you can find online and give it a try. Go slowly, practice on scrap pieces first, always dry clamp (figure out your clamp configuration and stuff without the glue before you glue something up) and know that you will likely have mixed results at first... some things will work, some things won't. And sometimes when you fix one thing, it reveals other problems.

On the other hand, if what you're after is an instrument you can play without too much work/cost, this is probably not the best one to start with. Start saving up for a vintage mando that is in better condition - not all of them are expensive. In fact, if you like bowlbacks, there are lots of them around for only a couple hundred bucks because they were once very popular (in the early 1900's here in the US), but aren't very popular any more.

--Edit: I just read that you are in Scotland... so the supply and cost of bowlbacks may be different there. My main points remain, however... this mando is not the one to expect to be playable without a LOT of work.

KE

[Jim Garber]

That would be brilliant Jim! I would love that! It just depends on the postage from where you are to Scotland.

Ah, that might be the problem. I recall it is quite expensive to ship since I am from the US. You might want to get in touch with Ian Steele. I know Scotland is a large place but he runs a mandolin school and also teaches with lots of kids your age who are interested in the mandolin. His Cafe name is trebleclef528.

I just checked and the cheapest would be around $100 (£63).

[j. condino]

I built my first guitar when I was 12, so regardless of what anyone else tries to tell you, I know that you can do this. Don't be in a hurry, seek out the advice of some sage old guys who know what they are doing, and proceed slowly. Make sure the only adhesive you use is hot animal hide glue. That is what it was originally built with and if you make any mistakes, it will be reversible.

j.
www.condino.com