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Some repair advice requested
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=12719		 Page 1 of 1
Author:  da_ardvark [ Thu Jul 05, 2007 2:11 am ]
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Hi, I'm to the forum (been lurking for a while) and I really love the free exchange of ideas and techniques which I see here. Now to the point. I'm not a professional luthier but I do work on guitars quite a bit. A friend of mine recently brought me this Godin with some damage. I as wondering if any of you could suggest some possible ways to best fix this damage. I was thinking of making a custom caul to fix the damaged area's shape and try to glue is with a polyurathane adhesive.


 



 



 


Thanks in advance.


 


Denny
Author:  blindreality [ Thu Jul 05, 2007 2:51 am ]
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 Split on the screws, ouch.
Author:  da_ardvark [ Thu Jul 05, 2007 3:19 am ]
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Yea, that what I think happened as well. I would have thought a pilot hole would have prevented this? Maybe they didn't drill a pilot hole.
Author:  Michael Dale Payne [ Thu Jul 05, 2007 3:34 am ]
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This will be a pretty easy repair and will be almost invisible. Use Hot Hide Glue as the glue. Finish repair will be the hardest part. I would put in a side brace to support the side at that location. Toughest part is the reach. If you are not familiar with the repair go to a pro.
Author:  da_ardvark [ Thu Jul 05, 2007 3:48 am ]
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I've never made a repair like this, but I already had planned something like you suggested (except for the glue type) I have relatively small hands so I should have no trouble getting into the sound hole to position and install the brace. Thanks for the advice though. I guess if it gets too hairy I'll seek out a pro. With regard to the finish match, I already prepared my friend that the crack may show up, and he seemd fine with that.
Author:  crazymanmichael [ Thu Jul 05, 2007 6:08 am ]
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this is the sort of crack where crack repair gadgets come in very handy. i would remove the fitting, compress the crack, drill the holes for the strings, feed the strings in, attach the cleats, apply either hhg or titebond and cinch it up tight making sure the crack is aligned in the best achievable manner.

as mentioned, finish repair will be problematic, but structurally it should be ok.

if you are unfamiliar with the gadgets i mentioned, there are some photos here:

http://www.luthiersforum.com/forum/forum_posts.asp?TID=11944 &KW=don+teeter#forumTop
Author:  crazymanmichael [ Thu Jul 05, 2007 6:09 am ]
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oh, for our long lost edit buttons!

i for got to mention, do not use pu glue in a crack like this.
Author:  da_ardvark [ Thu Jul 05, 2007 7:26 am ]
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Thanks again for all the replies. Michael, I had to laugh when I read you idea, because I was describing the exact thing to another guitar playing friend of mine and he looked at me horrified. Because of the location of this crack do you suppose I could just use the guitar machine heads in lieu of these little devices? Of course I would protect the guitar carefully from the string comming out of the sound hole.


You guys are very generous in your suggestions and ideas and I am forever in you debt. I'll post pics of the repair assuming they don't go terribly wrong


 


 
Author:  John How [ Thu Jul 05, 2007 7:34 am ]
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Looks like the perfect time to invest in some nice strong rare earth magnets, one on the inside and one on the outside every inch or so should hold things in alignment just fine. Whichever glue you use, start at the wide part and work towards the butt. Do a dry run first though.
Author:  KenH [ Thu Jul 05, 2007 9:01 am ]
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I saw someone using some of the string clamps a while back to repair a crack in a guitar top. The resulting repair was almost invisible and the miniature holes for the strings to come through were all but undetectable. makes good use of some old dead strings...


One thing they did with the clamps was to coat them with wax before gluing...  made them so that the glue didnt stick to them.
Author:  crazymanmichael [ Thu Jul 05, 2007 10:03 am ]
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have no idea why he was horrified. they have been a standard repair too for 40 or 50 years.

players look at you horrified when you tell them you just knock off old nuts too, but then most players don't know one of a guitar from the other, technically speaking that is.

the tuners alone won't work; too unstable.

john's suggestion of magnets is also good, if you can get your hand that deep into the lower bout to place the cleat and inside magnets. my arm is too big...
Author:  PaulB [ Thu Jul 05, 2007 10:09 am ]
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[QUOTE=John How] Looks like the perfect time to invest in some nice strong rare earth magnets, one on the inside and one on the outside every inch or so should hold things in alignment just fine. Whichever glue you use, start at the wide part and work towards the butt. Do a dry run first though.[/QUOTE]

You can also find rare earth magnets in old hard drives; that is if you're like me and too cheap to buy them.
Author:  Greg [ Thu Jul 05, 2007 1:05 pm ]
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Lots of very good advice here. Also, take a look at Frank Ford's wonderful site: frets.com. there may be others with his experience but I would wager very few.
Author:  da_ardvark [ Fri Jul 06, 2007 6:06 am ]
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Man you weren't kidding about Frank's site


Lot's of great pictures of lot's of great repair techniques.


Thanks.


Michael, I don't want to sound stupid, but how exactly are those little tuner things positioned. Are there any pics of these in action?


Thanks a bunch Paul. I have a butt load of old hard drives and I salvaged 5 sets of magnets. One set is really really strong.


I got some hot hide glue. I've never used it before so I think I'll mix some up and glue up some scrape first so I can see the setting times.


Would I apply the HHG to both sides I'm joining or is one side ok?


 


Thanks again everyone. I feel alot better about this repair already.


 


 
Author:  crazymanmichael [ Fri Jul 06, 2007 12:54 pm ]
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the flat or rounded base surface with the tiny hole in it goes against the crack, the open side is away from the crack. the curved bases are used for cracks in the waist, while the flat bases are used on the convex surfaces. the first and second photos in the thread i referenced earlier show the gadge in position to use if the crack were in the carpet square.

close the crack and drill the hole with an appropriate sized numbered drill.

for the the string, i like g octaves from 12 string lights (.008"). feed the string though the tuner post, through the hole in the base and through the hole in the side.

fish the string out through the sound hole, put on the cleat, a caul, and tie the ball end back on the string.

apply the glue to the crack and clamp it closed. apply the glue to the cleat, pull the string tight through the tuner, and crank the tuner tight. let dry.it is best to try to align the long axis of the cleat with the crack if you can reach it. if you can't, just use a round cleat. perhaps not as tidy looking but every bit as effective, and not many folks are ever going to see it anyway.

as was mentioned by someone when forgotten by me at the time, wax the gadget and the caul to prevent the glue from adhering. best to do so each time you use it.
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