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9 Attachment(s)
Gibson Mandola Restoration
Hi everybody, new here. I just purchased a vintage gibson mandola with some real cracking on the top. I was hoping for all info on DIY repair and restoration processes, dos and don'ts, and some help navigating quality (but minimal) new luthier tools. I have spent lots of time working on vintage guitars and some on acoustic guitars.
I will remove the back, recreate symmetry using the good side to make a template, gently heat/steam press the top back into shape with special molds, glue/wood dust crack fill, scrape excess, brace along the crack (looking for suggestions here on not affecting the tone while providing structural support), check measurements and symmetry nut to bridge, then refinish. Other tasks will likely come up as I go but that's the current plan.
I plan on refinishing most of the guitar, hopefully leaving the sunburst in tact and adding a good clear coat over top. But I will likely remove most of the sides and back finishing and smooth over nicks and dents. Excited to share my new project! I will be reappraising my entire plan open personal inspection and while I would like to do everything myself, will resort to professional assistance when needed.
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Re: Gibson Mandola Restoration
Congratulations on seeing that this is in need of some restoration.
Also, very wise to seek out some help simply because mandolin Luthiery is significantly different from what you have done in the past. I’m not saying you can’t do it just that prepare yourself for learning an entirely new set of concepts.
The idea of refinishing makes my hackles rise! No, you need to “restore” not destroy original ANYTHING if you can avoid it.
Please search some threads here on each step, none are impossible but you need to understand that it is the farthest thing from a “little guitar” and something completely different.
I’m not trying to be flippant or disparaging but, you do need to think of a completely different set of engineering problems. Just wait and proceed slowly.
I’m not a builder but have been lucky to have been around some very very good luthiers and it takes time to learn the ins and outs.
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Re: Gibson Mandola Restoration
Caution is the better part of valor. 'Vintage guitars and some acoustic guitars' to me means electric guitars and a few acoustic guitars. Mandolin family instruments are quite different.
Refinishing original instruments typically reduces value a considerable amount, so you'd be wise to do as little as possible. Crack repair is better done with wood than glue and dust and refinishing can be done with touchup and feathering as needed. Taking the back off is a major undertaking, and replacing or reusing the binding will be a considerable challenge among the issues there. I'm sure the seasoned repair folks on the forum will advise similarly.
You might want to examine the many threads in the builders and repair forums here. Not a lot has been missed in the discussions, you might start with this thread: https://www.mandolincafe.com/forum/a...p/t-44804.html
Good luck, and be patient.
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Re: Gibson Mandola Restoration
Slow down, ask advice (as you have done here), be realistic about your abilities and seek pro help when you need to.
This is not an easy project, even for the experienced repairer. If it was me, I would wait until I had the instrument in hand and spend plenty of time examining and putting together a master plan including goals and procedures, then take it one step at a time. Try to disturb the original finish as little as possible, try to disturb the original wood as little as possible, and try to make it end up looking like nothing happened.
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Re: Gibson Mandola Restoration
'Good candidate for the ramen noodle repair guy:
https://www.youtube.com/watch?v=HF2LJ7JDauU
;););)
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Re: Gibson Mandola Restoration
I agree with the expert opinions above. I've heard it stated, first rule of vintage instruments: don't mess with original finish, second rule of vintage instruments: don't mess with original finish.
Think it through and plan out the results. Most people would rather have a touched-up crack repair with original finish surrounding it than a completely refinished top.
I did notice if you look at the top, the pickguard will conceal about 50-60% of the repair, the dark portion of the sunburst at the tail end will hide another 20% of the problem once touched-up, so the real challenge is the remaining 20% and to accurately touch-up the yellow portion of the sunburst, so the repair is believable, IMHO.
It is easy to overdo it. Plus some people just like refinishing things -- and they shouldn't be in the vintage repair business, IMHO.
Nice piece. Good luck, I'd take it to an expert if it were mine.
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Re: Gibson Mandola Restoration
That is a real beauty. Any idea what happened to it??? I wouldn't try it myself.
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Re: Gibson Mandola Restoration
To me, it appears that the top finish has already been compromised-- the colors are just not right. I don't think it's been completely redone, but I sense the presence of at least an outer coat of some sort of lacquer. The back and sides may still be original, but the pictures are not clear enough for me to tell.
We avoid the use of fillers when repairing cracks. If necessary, we splint in new wood. I suggest that you do some research into violin crack repair techniques. I think that several of them would be applicable here, especially in the approach to reinforcing the cracked area of the top.
If you are really good and clever, it may be possible to repair the top without opening the instrument. Or it may only be necessary to loosen the top for a few inches only to aid in closing one or two of the cracks. This is one of the violin techniques that I referred to.
Opening a guitar or mandolin completely is a technique of last resort. We avoid it whenever possible.
If you do find it necessary to open the back, be advised that there is a short nail embedded in the joint between the back and the neck block, and another between the back and the tail block. They were used as locating pins when the instrument was originally assembled. They are only a mm or two long, and you can work around them without too much trouble, but you will bump into them when you try to open the glue joints at the blocks.
And yes, this is a major undertaking, and will require a step by step approach. It will probably be advisable to execute the crack repairs in several glueings, rather than just one or two.
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Re: Gibson Mandola Restoration
My understanding is Gibson did overspray some older instruments when they were brought to them for repair. This may be one.
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Re: Gibson Mandola Restoration
Is that a drywall screw in picture #2?
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Re: Gibson Mandola Restoration
Not trying to pile on, but I'll join the growing chorus on this thread to please rethink your plan of "refinishing most of the guitar, and adding a good clear coat over top." That sentence gave me chills. IMO, that is just not wise for so many reasons.
You asked for advice; this would be a good one to consider.
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Re: Gibson Mandola Restoration
Quote:
Originally Posted by
j. condino
Oh, my.
So many things about that video are equal parts disturbing and hilarious. Love the tuners!
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Re: Gibson Mandola Restoration
Thanks everybody for the feed back. I am convinced to:
Leave the finish alone!
Attempt to repair the crack through humidifying and bracing without removing the back. After humidity swells the cracks it is time to reassess.
I am confident I can glue the cracks, but I know that the arch of the top will prove a new challenge. Any information on restoring the original contour through humidity, heat, and supported pressure without removing the back? I am assuming that the braces may have suffered during the top cracking. The mandolin family will be a new experience in my wood working knowledge.
In terms of the finish I was mostly interested with uncovering those circular dents in picture #2, believing refinishing would be appropriate. Any thoughts on those, are they signs of service, best left alone if the instrument plays?
Best,
Ian
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Re: Gibson Mandola Restoration
Quote:
Originally Posted by
Mandyourmanners
Thanks everybody for the feed back. I am convinced to:
Leave the finish alone!
Attempt to repair the crack through humidifying and bracing without removing the back. After humidity swells the cracks it is time to reassess.
I am confident I can glue the cracks, but I know that the arch of the top will prove a new challenge. Any information on restoring the original contour through humidity, heat, and supported pressure without removing the back? I am assuming that the braces may have suffered during the top cracking. The mandolin family will be a new experience in my wood working knowledge.
In terms of the finish I was mostly interested with uncovering those circular dents in picture #2, believing refinishing would be appropriate. Any thoughts on those, are they signs of service, best left alone if the instrument plays?
Best,
Ian
Ian,
I thought at first that one of the circles/indents in #2 photo looked like a drywall screw head, upon a closer look, I now wonder if they are either wood plugs covering dowels or screws, or perhaps just putty covering something?. I might be tempted to scrape a little material away on one of the indents using an exacto blade.
As far as braces go, Gibson used one brace positioned under the sound hole. You should be able to touch it with your finger. Not uncommon for the treble end of the brace to come loose and as a result, the top would sink a bit.
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Re: Gibson Mandola Restoration
The circular marks might be clamp marks from a previous amateur repair. Or, like you say, maybe filler or a plug hiding screws, again from a previous repair.
Just a guess....
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Re: Gibson Mandola Restoration
The circles on the back look like they are covering some sort of well-meaning but misguided repair attempt. No substitute for examining the instrument in hand to determine what they are, what was done, and what to do about them. It is exactly the kind of thing we run into frequently in repairs; something that would have been better left alone if it couldn't be repaired correctly.
Whatever it takes to remedy them, it will almost certainly require finish touch-up, but almost certainly not require refinish.
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I was thinking of removing some material like you suggest Jim Simpson, but priority is the top. I have been reading around that some old gibson carved tops benefit greatly from additional supporting braces added to the top. I think the treble side of the brace will be loose. If the crack repair has gone well I will glue the treble end of the brace back on tight without removing the back, sounds like playing operation as a kid but doable with time, planning, and precision.
My biggest question remains whether to add additional supporting braces or not. I do not want to remove the back but would consider doing so if that would allow for additional bracing that would improve the life of the instrument. This restoration is to be a player, not decor, so I want to work on it so it will last well traveling in a tightly sealed, humidified case.
Thoughts on additional bracing to improve the life of a vintage gibson top? My opinion is if its compromised already, do as little as possible to it and play it while it lasts. Down the road maybe hire a luthier to carve a new top for it when the original one gives.
Additionally, any info on pick guard brackets? This one is included but 'unusable'. I would love to see some creative woodworking on this that in no way penetrates the instrument.
Thank you kindly for the support thus far,
Ian
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Re: Gibson Mandola Restoration
Ian,
Rebracing would seem to require taking the top or back off. I would try fixing the current brace, if loose (with hot hide glue) and repair the cracks. I've read of some rebracing with an x-brace but again, premature. This would be an ambitious project for most so caution is definitely the way to go. Keep us posted and good luck!
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Re: Gibson Mandola Restoration
Required reading:
Complete Guitar Repair by Hideo Kamimoto
The numerous articles on Frank Ford's excellent website: www.frets.com
Often, when the brace is reglued, it will push the top back close to its original shape.
Cracks can be reinforced with cleats or thin wooden strips. Keep the reinforcements as small as possible. These techniques are described in the sources above.
A pickguard clamp can be made from a Hill style viola chinrest clamp, available from a violin supply house. You may have to replace the support arm with a piece of threaded rod and make a mounting block for the arm and clamp out of a piece of plastic or wood. See the current thread "Pick guard for 1912 A4 Gibson."
You will do much better if you will take the time to study the Kamimoto book and Frank Ford's articles. I will again suggest that you also study some of the in-print resources on violin repair. The Kamimoto book is $28 new, and you can find a used copy for half of that.
Internet forums are a great thing, and there is often some great information to be gleaned from them. But there is also a lot of bad information, and it can be difficult for a beginner to be able to discern the difference.
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Re: Gibson Mandola Restoration
"......Internet forums are a great thing, and there is often some great information to be gleaned from them. But there is also a lot of bad information, and it can be difficult for a beginner to be able to discern the difference."
+1000
That is a polite way to say it!
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Re: Gibson Mandola Restoration
I have found that maintaining a polite attitude is beneficial, not only in social matters, but also from a business point of view. There are other benefits as well.
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Re: Gibson Mandola Restoration
So true, especially with the shelter-in-place and social distancing, which basically translates to people having too much time on their hands -- therefore -- hey, call the repairman and say, "when is my guitar gonna be ready?" I wanna say, "you idiot!, but something stops me.......I realize that being nice to that idiot is how I get paid!"
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Re: Gibson Mandola Restoration
Thank you for the excellent reading recommendations rcc56, they are much appreciated.
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Re: Gibson Mandola Restoration
Quote:
Originally Posted by
rcc56
A pickguard clamp can be made from a Hill style viola chinrest clamp, available from a violin supply house. You may have to replace the support arm with a piece of threaded rod and make a mounting block for the arm and clamp out of a piece of plastic or wood.
If I'm not mistaken, I have a little bag of 20 or so of those viola chinrest clamps, which is far more than I'm going to need. I will happy to send one along if you'll cover the postage. Send me a private message through the Cafe.
That is a pretty nice H2 apart from the crack. I looked at it a few times but ended up with one from a few years later, which will have its own repair tribulations, already discussed elsewhere. I am curious about the case -- it appears to be a nice custom case from the 1970s or thereabouts.
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Re: Gibson Mandola Restoration
Kamimoto's book is in the mail and I'm learning lots from frets.com. Thank you so much, this is why I'm on this forum!