Members DarkHorseJ27 Posted July 17, 2009 Members Share Posted July 17, 2009 I have long had the urge to work on and fix my own guitars, and installing a saddle on my own has only increased that. I know find a guitar on Ebay that is a model that I really want, and I doubt it will go over $100 because of a long crack going from the bridge to the bottom of the top. The crack is very narrow. Should I really consider buying it and fixing it myself? Link to comment Share on other sites More sharing options...
Members S~R~O Posted July 17, 2009 Members Share Posted July 17, 2009 http://www.frets.com/ Three top cracks in this 1887 Martin guitar extend from the bridge all the way to the end of the body: They are structural cracks, but will not affect the longevity of the guitar even if they are left wide open and not repaired at all. Spruce has very little strength across the grain, and the pull of the strings is never in that direction. So, lengthwise cracks have little effect on strength in this area, where the only force is with the grain. The wide bridge (now off the guitar) distributes the load across six inches of the spruce, so it's able to handle the tension very well. http://www.frets.com/FRETSPages/Luthier/Technique/Guitar/Structural/Cracks/LG2TopCrack/lg2topcrack.html http://www.frets.com/FRETSPages/Luthier/Technique/Guitar/Structural/Cracks/Taylor355Cracks/355cracks.html Link to comment Share on other sites More sharing options...
Members DarkHorseJ27 Posted July 17, 2009 Author Members Share Posted July 17, 2009 http://www.frets.com/ Three top cracks in this 1887 Martin guitar extend from the bridge all the way to the end of the body: They are structural cracks, but will not affect the longevity of the guitar even if they are left wide open and not repaired at all. Spruce has very little strength across the grain, and the pull of the strings is never in that direction. So, lengthwise cracks have little effect on strength in this area, where the only force is with the grain. The wide bridge (now off the guitar) distributes the load across six inches of the spruce, so it's able to handle the tension very well. The guitar in question has a cedar top, but I don't see why it would be much different that spruce in that regard. I found some sources on such repairs, and they actually don't seem too difficult, nor the prices of the needed items from Stewmac that much. Link to comment Share on other sites More sharing options...
Members S~R~O Posted July 17, 2009 Members Share Posted July 17, 2009 Note: see other web addresses at bottom of my first post for further detail on crack repair. Link to comment Share on other sites More sharing options...
Members C70man Posted July 17, 2009 Members Share Posted July 17, 2009 ....I know find a guitar on Ebay that is a model that I really want, Sounds like a no brainer to me.....cracks are no big deal. It's about liking the guitar....and you seem to like it. Link to comment Share on other sites More sharing options...
Members knockwood Posted July 17, 2009 Members Share Posted July 17, 2009 Bondo. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted July 17, 2009 Members Share Posted July 17, 2009 Top cracks, particularly if it is the center seam, are usually caused by dramatically under humidified guitars (which means there may be other problems). In some cases repair is as simple as rehumidifying and wicking some CA into the crack. Normally, however you need to glue up the crack and "cleat" it with some small braces inside which presents all sorts of problems of how to clamp them. You might check out both StewMac littles sissor jack and also the use of strong magnets for clamps (StewMac sells them also and has a section in their tech tips on how to use them) The other common top crack is the so called Martin pickguard crack - most Marties from the 70's have one. The fix is to remove the p/g, cleat the crack and put on a new p/g over the finish. The best glue is hot hide but for most of us thin CA works OK. Then you have the problem of how to fix the finish - sometimes you can drop fill (CA or whatever the parent finish was) but sometimes you'll have to respray. I fixed a humidity crack using magnets for clamping cauls and had a pick guard crack fixed on my 74 D-18. I can be done, but in general I would stay away from a crack git unless it was something I really wanted. Link to comment Share on other sites More sharing options...
Members guitarcapo Posted July 17, 2009 Members Share Posted July 17, 2009 Usually what I will do if the crack is small (not really a gap, just a line)is to wick in some very thin CA glue into the crack. It's a thing of beauty to watch: You just start at one end with super thin CA in a bottle with a micro-pipette tip. The glue just travels up the crack and goes everywhere it should (and nowhere it shouldn't) via capillary action. You can find the right glue and tips from those hobby store that sell RC model airplanes. Just let the guitar sit for an hour and press lightly on the top. If the whole soundboard moves as one then you have sealed the crack. I like to seal these cracks even if they aren't structural because if dirt works into them over time, then the wicking trick won't work, and the crack becomes a black line instead of being invisible. Bigger cracks with gaps are more difficult. you have to use a crack repair knife and open up/clean out the crack uniformly. Then add a splice of wood and wick in the CA glue afterward. It's pretty hard to make this repair totally invisible, and there's usually finish repair involved too. An old trick is to color the splice a little bit the match the surrounding wood after gluing it in... and then French polishing over this. Crack repairs look cool to me on vintage guitars even if they show, though. Just another "relic" feature. Sometimes you can find a great deal on a vintage guitar because it has a crack. It can save you hundreds and often is an easy fix if you care more about playing the guitar instead of it's value as a collector's item. Link to comment Share on other sites More sharing options...
Members SoloArtist Posted July 17, 2009 Members Share Posted July 17, 2009 I don't mean to try to hyjack this thread but I wanted to know how to clean and maintain a hand rubbed finish top? My Little Martin has a solid spruce top but not the usual glossy nitrocellulose laquer my other Marties sport. It just looks like a bare invitation for dirt & grime to work it's way in. I currently use Planet Waves guitar cleaners & polishes as well as a spray from Fender (McGuires). Its a brand new git so I won't be polishing the soundboard anytime soon anyway. Link to comment Share on other sites More sharing options...
Members Freeman Keller Posted July 17, 2009 Members Share Posted July 17, 2009 I don't mean to try to hyjack this thread but I wanted to know how to clean and maintain a hand rubbed finish top? My Little Martin has a solid spruce top but not the usual glossy nitrocellulose laquer my other Marties sport.It just looks like a bare invitation for dirt & grime to work it's way in. I currently use Planet Waves guitar cleaners & polishes as well as a spray from Fender (McGuires). Its a brand new git so I won't be polishing the soundboard anytime soon anyway. Damp cloth is all I every use, including my satin finished Taylor. What your little Martie has is still a nitro finish, but it has NOT been polished. Sprayed (by a robot) just like the rest of the Martin line, but they leave out the final (by robot) buffing step. Link to comment Share on other sites More sharing options...
Members SoloArtist Posted July 18, 2009 Members Share Posted July 18, 2009 Damp cloth is all I every use, including my satin finished Taylor. What your little Martie has is still a nitro finish, but it has NOT been polished. Sprayed (by a robot) just like the rest of the Martin line, but they leave out the final (by robot) buffing step. Thanks Freeman! Yep, that's just what the little booklet said that came with it. A damp cloth. I saw the Polishing Robot too when I did the Martin factory tour. "Hand rubbed" finish is just a descriptive term. The only hand rubbing going on will be mine. Much appreciated. Link to comment Share on other sites More sharing options...
Members platinumT Posted August 7, 2009 Members Share Posted August 7, 2009 Hey guitarcapo, I have an Epiphone Masterbilt DR-500R with a spruce top and an extremely tiny crack (I didn't even see for a few weeks after buying it) running from the bridge to the bottom of the guitar - what kind of instrument should I use to get some glue in there? And where can I get this CA? Thanks! Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.