Mando repair

[petersemple]

I would love some advice on repairing my mando. It's pretty badly busted, and it isn't a particularly good one, so a lot of people would probably say that it isn't worth it, but it was a gift from my parents for my 21st, so it has a lot of sentimental value. The soundboard has cracks in it down both sides of the fingerboard, right up to the soundhole. The upshot is that the neck collapses into the body, and the whole instrument bows. I suspect that the best thing would be to remove and replace the soundboard, but I don't think I would do that. I suspect that building a new one from scratch might be easier. If it helps, I do have some 5mm thick spruce that will one day be a guitar that I can cut some small pieces from for reinforcing. I have a few photos to show what happens.

[Groundhangers]

First thing is to take off the strings. It will relieve the pressure causing any further damage.

This is just my opinion. I would just glue it back into its original place and strengthen it a little from the inside so it can hold strings again. With a little care you could probably get it back to an acceptable level cosmetic wise. By the sounds of what your saying its not a very good player and probably never will be unless some major work is performed.

I too have a guitar that was given to me by my parents when i was 7, it was my first and it was the guitar that started it all for me. When i was 20 we all got drunk one night (as you do) and used it as a cricket bat. The fretboard came away from the body and a little after it got whacked against the floor snapping the neck in 2 places, not to mention the split in the soundboard. So it sat in the bottom of my cupboard and i hated myself for doing what i had done every time i looked at it. Anyway, 15 years and numerous guitars later i couldnt stand it any more, so with what little knowledge i had i fixed it to the best of my ability so that it at least could stay in tune. It actually played ok again. I did think about changing the neck, but it would have never been worth it. Now im 47 and I havent played it for many years now, it just stands where ever anyone moves it to in the house and occasionally just run my fingers through the strings and smile. Looking pretty much the same as it originally did all those years ago and still 100% all there.

If you want a half decent player, just go buy one or even make one.
As for sentimental value, It doesnt have to play well. I dont even think you need to look at it. You just need to know that its there. Thats all that counts.

Sorry for the ramble.
Greg

[petersemple]

Yeah, I have the strings off (well, they're still there, but there's no tension). I have no idea whether it's a good player or not. I like the sound of it personally, but it's the only one I have ever played, so I have nothing to compare it with. I know that the cosmetic details are cheaply done, but it's nice to play. I had indeed wondered about gluing it back in place with some thin pieces of spruce underneath (probably with the grain running crosswise to the grain of the top). Is that the best approach? If so then what size patches, where, and how thick would be the best compromise between strength and not sacrificing too much tone? Anyone know?

Thanks

[catweaselmusic]

Hello Peter, The proposed repair of your mandolin sounds quite feasable, the fitting of cleats under the soundboard cracks with crosswise grain is the usual method of repair. Please note though, do not use PVA white woodworkers glue for anything on musical instruments except gluing a label on! This glue is too soft and develops creep on the joint. Aliphitic glues are the industry standard, "Titebond" being the favorite. Hide glue is also good. Remember that the neck angle is important to get correct, keep a G and E string in position (loosly) to determin the string height over the frets before gluing the cracks. My method is to tie the mando over a stiff piece of timber and fit packings until the correct height is achieved. Hope this works for you. Regards catweaselmusic.

[petersemple]

Thanks, yeah, I have Titebond. My last major project was a bass guitar, and I used Titebond for that. What size/shape/thickness is the best to use for the cleats?

Thanks

[Sebastiaan56]

Hi Peter,

David Hynds has good instructions here, Home (http://www.mandolinluthier.com/Htable.htm) You will need to patch the cracks but it may well be that a brace has let go as well. Good luck. Do you reckon you can post a few more piccies for an old mando perv?

[petersemple]

OK, it's taken me a while, but here are some more photos. I am pretty sure the scratchplate isn't original. I tried to do the label from the headstock, but it didn't turn out very well. The label says: "Carmencita".

It looks like small (10mm or so), cleats that are tapered in thickness are commonly used for violin repairs of this sort, so I think I'll give them a go. I suspect the soundboard in this area doesn't move that much as it's close to where the fretboard is glued on. Hopefully that means the sound won't change too much.

[catweaselmusic]

Hello again Peter I have just seen your photos of your mando, It is an nice instrument but that pick guard is a dog. Not original and poorly made. Regards Bob

[petersemple]

Yeah, I have wanted to remove the pickguard for a while. This might be my moment. Thing I am concerned about is the appearance of the holes that would be left in the top. Maybe I'll just leave the holes there - can't look worse than that guard.

[Groundhangers]

Youll be able to cut up a nice custom thin stick on one to hide the holes.

[catweaselmusic]

Hello Peter, If you make a new pick guard you could plug the existing holes so as to fit smaller raised head screws at used on the Fender Stratocaster. The new guard pattern could be made in stiff cardboard and tailor it to follow the arc on the sound hole and the outer 'bout. The template can then be use to make the real one. I recently made one in wood for a Telecaster whose owner had so much static in his body that he would charge the pickguard and then it started crackling. It was stained dark walnut and looked very smart. (crackling stopped) regards Bob

[petersemple]

Grrr, the forum ate my post. Trying again.

I will update this thread as I go with what I have done. It will take a while though as I don't have a lot of time.

I have removed the finger rest and the damage on that side is worse, as I suspected. There aren't any braces under there though, which is one less worry. I intend to use the above method of clamping it in the correct place and the gluing the cracks shut, followed by gluing cleats in behind.

As you can see, the finger rest was help off the soundboard by brass and rubber washers. which have left quite a mess. I may make a better one to cover it over, but I must admit I like the look without. Frank Ford details a method of repairing and hiding these kind of holes on his website, but it's a bit complicated and I'm not sure if I have the courage. I guess we'll see

Thanks

[jeffhigh]

If there are no braces under that area, then I think you should add one.
A few cleats are unlikely to hold up against string tension.

[catweaselmusic]

Remember that the grain on the cleats run 90 degrees to the soundbroad this improves the shear strength greatly. The Mando stood up the the strain inline with the grain of the soundboard for quite a long time. Purfling can be used as a guide to locate the neck during repair. regards Bob

[jeffhigh]

Remember that the grain on the cleats run 90 degrees to the soundbroad this improves the shear strength greatly. The Mando stood up the the strain inline with the grain of the soundboard for quite a long time. Purfling can be used as a guide to locate the neck during repair. regards Bob

This may be a glass half full/ / glass half empty thing, but whilst you see the mando having stood up to the strain for a long time,, I see it as having eventually failed due to lack of bracing..
I gould be inclined to fill the whole area from soundhole to neckblock with a thin crossgrain patch.
A couple of cleats each side will not restore the original strength in this area let alone improve it.

[petersemple]

This may be a glass half full/ / glass half empty thing, but whilst you see the mando having stood up to the strain for a long time,, I see it as having eventually failed due to lack of bracing..
I gould be inclined to fill the whole area from soundhole to neckblock with a thin crossgrain patch.
A couple of cleats each side will not restore the original strength in this area let alone improve it.

I do like this idea, and may well use it. I have a whole guitar soundboard worth of spruce to use if I need it - and can cut out a decent sized patch and still leave enough to make a guitar in future. I will certainly be a lot stronger, and I like the idea of a large thin patch more than an added brace.

[catweaselmusic]

Agreed.

[petersemple]

OK, finally.

I took off the bridge and tailpiece, and clamped it to a board. Made sure the purfling lines were properly aligned. I then cut a piece of sitka spruce to fit inside. Took ages because most of my tools are packed away. Would have loved a scroll saw instead of a knife. Next step is to glue back disturbed binding, and restring it (might just spring for a new set of strings too).