Sask Mark Posted January 9, 2009 Share Posted January 9, 2009 I don't know if this is the best place to post this, but here it goes... I'm trying to repair an electric guitar bridge. The material is plated die cast metal. One of the threaded holes that a fine tuner bolt threads into is stripped out. What do you all recommend as the best way to fix this? I was thinking of using a JB weld type of compound in the stripped hole and drilling & tapping new threads in it. I have to keep in mind that the threads are very fine (the bolt is M3.5 X 0.6mm). The threads don't have to tolerate any large amounts of torque (the tuners are turned by finger, not with tools). Will a compound like JB weld take threads this fine? Is there another compound that works better? I don't want to use any hot processes so I don't ruin the surrounding plating. As well, spare parts for this bridge are very hard to find because the guitar hasn't been made in about 15 years, and it was only produced for 2-3 years in limited numbers. Thanks for all your recommendations. Quote Link to comment Share on other sites More sharing options...
NOS Posted January 9, 2009 Share Posted January 9, 2009 Oddly enough I am a Luthier and have been a professional musician for about 20 years. You can only imagine my shock to see a guitar question here on IFI. I can say that JB weld will hold a thread, but not in the permanent application that you have. The reason that I think you will have a problem making JB weld a permanent fix is the amount of pressure on the bridge. You have to think about the combined amount of tension psi with the strings. my guess is that it is a standard 6 string electric. At around 1500psi of tension on the neck, and about 300psi on the down force to the bridge. This all depends on string Gage,the action, as well as the neck adjustment and bridge height. If everything worked out perfectly, I would say it would be a temp. fix at best. It can be done, but with all the variables involved, I would say look for a replacement part. What brand and model is it? You can find many replacement and universal parts from some companies on line cheaply. I can send you a list of some of the companies that I buy from if you are interested. Feel free to PM me and I can give you a list of companies that can help you. Hope this helps.:) Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 9, 2009 Author Share Posted January 9, 2009 Thanks for the advice NOS. I'm also a guitar geek, so now that I know there's a luthier in the crowd I might throw some other guitar questions your way. It's for the tuning knobs on the locking bridge (Floyd Rose Liscenced) on a Yamaha SE1212. I think the SE1212 and the RGX1221 were the only guitars to use this proprietary bridge (both 6 strings with double locking trems). I will probably run 9-42 or 9-46 guage strings on it. This bolt isn't subjected to the full tension of the strings, it just has to depress the saddle to increase or decrease the string tension on a fulcrum. That is why I thought the JB weld MIGHT work. I have searched ebay, Stew Mac, Luthier Supply, Warmoth etc. and have nerver seen another bridge like it. The part that is stripped is the 'chassis' for the bridge. Maybe when I get home tonight, I can take a picture and post it so you can fully understand what I am up against. Quote Link to comment Share on other sites More sharing options...
belargehair Posted January 9, 2009 Share Posted January 9, 2009 Could you tap it for the next screw size up? I know it would be different than the other set screws, but just a thought. You can get threaded inserts, but I don't know how hard it would be to find one small enough. Or, maybe epoxy a new piece under the plate and drill/tap a new hole in it? (guitarist/drummer for the past 17 years.) Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 9, 2009 Author Share Posted January 9, 2009 Could you tap it for the next screw size up? I know it would be different than the other set screws, but just a thought. You can get threaded inserts, but I don't know how hard it would be to find one small enough. Or, maybe epoxy a new piece under the plate and drill/tap a new hole in it? (guitarist/drummer for the past 17 years.) The tapping with a larger screw size is an option if I exhaust all the other ones for keeping the existing screw sizes. I looked at running a Helicoil (threaded insert), but the kit alone for the M3.5 X 0.6 screws is about $70 (they are available through various stores online). I don't know if I'm willing to spend THAT much on it. As for your epoxy idea, the problem would be you can't interfere with the clearance between the piece with the threaded hole and the fulcrum beneath it, or you will lose most of your tuning range with the screw. Epoxying a piece beneath would reduce this clearance. Thanks for the all recommendations. Keep 'em coming! Sooner of later, one will pop up and I will think 'now why didn't I think of that?' Quote Link to comment Share on other sites More sharing options...
belargehair Posted January 9, 2009 Share Posted January 9, 2009 Drill out, oversize and tap the old sloppy hole, insert/epoxy threaded rod, drill out new hole through threaded rod and tap? Basically making your own insert. $70? yikes. Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 9, 2009 Author Share Posted January 9, 2009 Hey, that might work without going the helicoil route. I guess I could make my own insert without too much difficutly and tap it! Thanks belargehair! Quote Link to comment Share on other sites More sharing options...
belargehair Posted January 9, 2009 Share Posted January 9, 2009 Well, as they say in the business... Rock on. Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 9, 2009 Author Share Posted January 9, 2009 I'm throwing up the horns right now! Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 9, 2009 Share Posted January 9, 2009 There are a number of epoxy putties available that should do the trick for you. Forget "Mighty Putty" it's the same stuff but WAY more expensive than just picking up a strip at the store. The putties are designed as fillers and material replacers rather than glues so they stay in place and closely mimic the material they're designed to repair. There are epoxy putties for specific metals too, "Marine Tek(x?)" for one is used to repair aluminum and is a darned fine product. I'd make sure there is plenty of texture in the hole for a good grip for the putty. Mix up just a little more than you think the hole would need to fill and press it in place. Then after it sets and before it hardens you can carve it easily with a razor, etc. Once it's fully hardened, drill and tap as needed. If it isn't going to be taking a lot of tension and or vibration it should do it for you. I'd still keep my eyes open for the part. Frosty Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 9, 2009 Author Share Posted January 9, 2009 Thanks Frosty. Once again, you are a wealth of knowledge. Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 9, 2009 Share Posted January 9, 2009 My, what a polite way to say I'm full of it. You are as always welcome to whatever I know, think or can make up. Hope it helps, if not now sometime in the future. Frosty Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 9, 2009 Author Share Posted January 9, 2009 I don't think you are full of it. If you are, you have me fooled completely! Sometimes making things up is the best way to solve a problem. Quote Link to comment Share on other sites More sharing options...
Frosty Posted January 10, 2009 Share Posted January 10, 2009 Okay, go ahead make me blush. Frosty Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted January 10, 2009 Share Posted January 10, 2009 Once upon a time ( a hundred years ago ) there was a product called Humbleweld. It was re-named Escoweld ( Humble Oil became Exxon ). This 2 part epoxy would machine somewhat and would thread. I repaired a cracked Kohler engine block with it and I ran the engine for several years. I suspect the repair is still good. Cleaning with a die grinder and scuffing the surface a bit to allow the epoxy to grab may be biggest thing. Vibration in a guitar bridge will be somewhat of an issue I suspect though. If all else fails you can just hard solder a piece in and paint the bridge a nice tie-died color and start a trend..... Quote Link to comment Share on other sites More sharing options...
Trollhammer Posted January 10, 2009 Share Posted January 10, 2009 Yet another rabid musician/repair guy. I once had some POS Lotus Strat rip off that was given to me because the previous owner stripped the fine tuner on the locking tremelo. I can't remember if it was a Floyd Rose, but it was similar if it wasn't an actual Floyd Rose. I used JB-Weld to do the same thing. It work pretty good for a bit, but the JB-Weld eventually flaked out. Now, this might have have been my fault, I was 16 at the time and my backyard engineering skills were horrible at best. Well, they're still not that great, but provide hours of entertainment. I eventually scrapped the entire guitar due to that and other issues(crappy frets that flattened out, neck pulling out of the soft wood body, etc.) It seems to me, and this is completely from a failing memory, that each saddle and fine tuner was independent. If this is the case, would you be able to machine that whole bit and replace it with that? Hope this helps. Mickey Quote Link to comment Share on other sites More sharing options...
NOS Posted January 11, 2009 Share Posted January 11, 2009 Sorry I didn't post back sooner, I was out of town on business for a day or two. I understand your question now. I think that Frosty's suggestion might be the best bet if you want to us a epoxy like product. drill and tap is another option, although you already know what that might set you back. FloydRose fine tuners can be a tough thing to fix on the licensed systems. However, there were a few years in there that they made some runs in stamped steel. If you feel like taking it out and looking on the underside of the main plate. scratch off a bit of paint and take a look. If it's steel, fill'r in with a weld and drill/tap your way to the promised land. I know that a few companies make oversized fine tuners in various thread types. Also see if you can find a Schaller "SCHALLOCK" (spelling?) for parts. The design was a locking tremolo ripoff, but the fine tuners were also a bit larger. I have used a few in the past to fis some of these issues. Let me know if you get it fixed or not. I have a network of some guys that may be able to help (for free beer, or a small fee ) Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 11, 2009 Author Share Posted January 11, 2009 Thanks for all the ideas guys. I did a little more research and it is the RM Pro tremolo. I pulled the bridge off the guitar and pulled it apart and found another stripped screw on one of the string clamp blocks. I think I will try the epoxy route first (it is the cheapest). I will have to order a couple of thread taps to do it. An M4 X 0.5 for the tuner screw and a bottoming M3 X 0.5 for the clamp block. If, by some freaky coincidence, anyone (nudge, nudge NOS) knows of someone with a spare tremolo kicking around, I would be interested. I would like to get this guitar back to running condition again as it is a very nice guitar (neck-through construction, ebony fretboard, active electronics etc). Quote Link to comment Share on other sites More sharing options...
NOS Posted January 12, 2009 Share Posted January 12, 2009 Sorry man, no extra parts for FR tremolo's around my shop. Those go the quickest. The only floyd I do have is ancient (not all were made the same size and shape inside the body cavity) and has the same problem as yours. I'll call around, but most of the guys I know just buy new ones. If I find something I'll let you know. Good Luck with the epoxy, let me know how well that holds up for you. :) Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted January 12, 2009 Author Share Posted January 12, 2009 Well, I finally got up the gumption to take some pics. Here is a picture of the bridge itself. Notice it is already a Frankenstein of a black and gold version from a few years ago. It probably deviates enough from a FR so Yamaha didn't have to pay licensing fees. Here is a picture of the underside of the stripped screw hole Here is a picture of the string block. The black part on the top is held down by a screw, the hole of which is also partially stripped. As you can see, I don't think there are any parts off an FR that will work on this bridge. Quote Link to comment Share on other sites More sharing options...
NOS Posted January 12, 2009 Share Posted January 12, 2009 Go with epoxy until you can find a "new" one, or replace with a FR trem. By the way, once you get it fixed, look into the Hipshot Trem-setter. That is the best thing ever invented for floating systems. You can bend individual strings up 2 whole steps without the other strings dropping in pitch. Thought you might want to look into it, in case you haven't already. I'll keep an eye out for one of those, but I doubt I will find one. Quote Link to comment Share on other sites More sharing options...
Sask Mark Posted February 17, 2009 Author Share Posted February 17, 2009 Just an update to anyone interested. I decided to forgo the JB Weld route and went with belargehair's suggestion. I used 1/4" rod and drilled and tapped a M4 X .5 hole in the centre. I then epoxied a short section of this rod into an oversized hole in the bridge in the form of a threaded insert. I did the same thing with a 3/16" rod for the M3 X .5 hole for the string lockdown block that was stripped. The repair seems quite solid. The threaded inserts will hold thread much better than the original casting did. The weak link will be the epoxy holding the insert in place. I can't see it causing any issues. I will work on the rest of the guitar (clean and oil the fretboard, polish the frets, set the truss rod...) then remount the bridge. Hopefully, all goes well! Quote Link to comment Share on other sites More sharing options...
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