Re-gluing a bridge - FRETS.NET2024-03-29T06:41:41Zhttp://fretsnet.ning.com/forum/topics/re-gluing-a-bridge?commentId=2177249%3AComment%3A112126&feed=yes&xn_auth=noPoly can be pretty tenacious…tag:fretsnet.ning.com,2013-07-06:2177249:Comment:1118532013-07-06T00:03:58.089ZHesh Breakstonehttp://fretsnet.ning.com/profile/HeshBreakstone
<p>Poly can be pretty tenacious but it does chisel up well. Lacquer usually is far less tenacious... We don't scrape the bridge patch and instead use a uber sharp chisel to slice away unwanted finish after we score the boundaries with a single edged razor blade.</p>
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<p>If you give this a try reading the top for the run-out direction is important here too as we don't attempt to chisel into the direction that the run-out is pointed and inadvertently lift fibers. </p>
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<p>Be sure…</p>
<p>Poly can be pretty tenacious but it does chisel up well. Lacquer usually is far less tenacious... We don't scrape the bridge patch and instead use a uber sharp chisel to slice away unwanted finish after we score the boundaries with a single edged razor blade.</p>
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<p>If you give this a try reading the top for the run-out direction is important here too as we don't attempt to chisel into the direction that the run-out is pointed and inadvertently lift fibers. </p>
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<p>Be sure too to clean up the old glue off the bottom of the bridge (I use a belt sander for the heavy lifting part) and then be sure to give the bridge bottom a fresh scrape just prior to gluing. A freshly scraped surface results in more "joint energy" than a surface that has not been scraped. Chiseling or scraping the bridge patch on the top is the other half and then you should be good to go.</p> Jack we do score the finish,…tag:fretsnet.ning.com,2013-07-05:2177249:Comment:1121292013-07-05T23:56:32.217ZHesh Breakstonehttp://fretsnet.ning.com/profile/HeshBreakstone
<p>Jack we do score the finish, always and yes it's a bit tricky and requires some decent vision as well..... I'm 56 and have more trouble doing this than my shop mate who is 36 and still can see.... ;) When he's not looking I have been known to increase the inset to perhaps .010 which is still not very much but I can at least see where I am going...</p>
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<p>Much of the stuff that we talk about on this very fine forum has to also take into account that not everyone here does Lutherie…</p>
<p>Jack we do score the finish, always and yes it's a bit tricky and requires some decent vision as well..... I'm 56 and have more trouble doing this than my shop mate who is 36 and still can see.... ;) When he's not looking I have been known to increase the inset to perhaps .010 which is still not very much but I can at least see where I am going...</p>
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<p>Much of the stuff that we talk about on this very fine forum has to also take into account that not everyone here does Lutherie as their day job. Many folks just want to fix up a project and come to us for decent ideas and advice. OTOH (on the other hand) many of the members here are pros and we benefit greatly too from exchanging ideas. One of the down sides of Lutherie in my personal view is that since it's often a solitary pursuit sharing information was back in the day not as easy as it is these days with the Internet and more interest in the subject from lay folks too.</p>
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<p>With that said some of the stuff that I offer may not be the best solution for the person who just wants to fix up a project guitar and be done with it. It's true that one has to be jigged-up to rabbit the bridge and it may not be a good approach for someone who does not want to spend their life making jigs to simply glue on one bridge.</p>
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<p>For these folks simply cutting back the finish closer to the bridge perimeter, being sure to remove old glue and finish from the top and clean it up well too, and with some fitting, proper glue usage for the glue that you decide to use, and appropriate clamping, cauls, curing time, etc. and Bob's your uncle. After all only about a zillion guitars have been made by the f*ctories with their bridge slapped on over a less than ideal gluing surface and they usually last long enough.</p>
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<p>Again there are lots of ways to do most anything that we do - A-men to that! Personally I am always fascinated by how things were done in the past, now, and perhaps in the future too. So I can get carried away at times and bring up stuff that perhaps has more academic value for those so inclined than the practical value of solving a real and present real world problem. So here's an apology from me for getting carried away and not staying focused on your project and what would best serve you going forward.</p> I don't know what finish is u…tag:fretsnet.ning.com,2013-07-05:2177249:Comment:1120492013-07-05T21:16:34.946ZJack Lordhttp://fretsnet.ning.com/profile/JackLord
<p>I don't know what finish is under tha lacquer but it's very hard to scrape off.</p>
<p>I don't know what finish is under tha lacquer but it's very hard to scrape off.</p> I can understand routing a .0…tag:fretsnet.ning.com,2013-07-05:2177249:Comment:1121282013-07-05T15:02:25.022ZJack Lordhttp://fretsnet.ning.com/profile/JackLord
<p>I can understand routing a .005" rabbet around the perimeter of the bridge with the proper fixture, but how in the devil do you mark the perimeter of the bridge on the top of the guitar (without scoring it) and remove finish to within .005"? Seems pretty tricky. Or, do you mask it before finishing? Still a pretty tricky masking job.</p>
<p>I can understand routing a .005" rabbet around the perimeter of the bridge with the proper fixture, but how in the devil do you mark the perimeter of the bridge on the top of the guitar (without scoring it) and remove finish to within .005"? Seems pretty tricky. Or, do you mask it before finishing? Still a pretty tricky masking job.</p> Amen to all of your thoughts…tag:fretsnet.ning.com,2013-07-05:2177249:Comment:1119412013-07-05T00:33:53.407ZEric Steven Johansenhttp://fretsnet.ning.com/profile/EricStevenJohansen
<p>Amen to all of your thoughts Hesh. The learning process never ends I hope.</p>
<p>Amen to all of your thoughts Hesh. The learning process never ends I hope.</p> It's a Drem*l mounted in a St…tag:fretsnet.ning.com,2013-07-04:2177249:Comment:1119302013-07-04T20:34:28.021ZHesh Breakstonehttp://fretsnet.ning.com/profile/HeshBreakstone
<p>It's a Drem*l mounted in a Stew-Mac router base with the addition of some additional hardware to end up as you see it. Typically the "tables" are radiused a bit, 25ish will do and of course the depth and inset of the rabbit is completely adjustable.</p>
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<p>Regarding your method, Nathan where you indicate it's best to score the finish around the bridge prior to removal this most certainly works well for you and if one is looking to cut the finish back under the entire bridge. That's…</p>
<p>It's a Drem*l mounted in a Stew-Mac router base with the addition of some additional hardware to end up as you see it. Typically the "tables" are radiused a bit, 25ish will do and of course the depth and inset of the rabbit is completely adjustable.</p>
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<p>Regarding your method, Nathan where you indicate it's best to score the finish around the bridge prior to removal this most certainly works well for you and if one is looking to cut the finish back under the entire bridge. That's one way to do it and I used to do this with my own guitars that I build.</p>
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<p>I moved away from this method in favor of the rabbited bridge perimeter because no matter how careful one is this method leaves zero room for slips and mess-ups... I had good success with it but I never liked being able to see the glue line even if only in very limited areas and looking specifically for it. It's an excellent way to go for improving the amount of wood-to-wood contact over what the f*ctories do not cutting back the finish closer to the bridge perimeter I would agree though.</p>
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<p>This idea of rabbiting bridges is not new and although I can't remember who introduced us on another forum to the idea years ago I do know that Collings has been doing it this way for a long time.</p>
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<p>What you end up with is a very neat and tidy bridge glue-up with the finish nicely visually extending under the bridge and no glue line or sloppy scoring showing at all. The trade off is the .003 - .005ish of bridge perimeter that we lose for wood-to-wood contact but again compared to how the guitar was originally manufactured it's a huge improvement in gluing surface area.</p>
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<p>Both methods benefit from the advantages of positioning, rapidly and correctly... the bridge in a well in the finish and the risk of the thing sliding around is minimized as well if properly positioned and the well matches the bridge rabbited perimeter.</p>
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<p>I also used to use a heat gun to heat up my bridges too prior to glue-up but these days lazy me likes the microwave for 15 - 18 seconds better. Besides the microwave is easier to use to heat up my pastrami on rye with Swiss sandwich too... :)</p>
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<p>I liked your toot as well Nathan and wanted to make a few other suggestions of other ways to do things too if I may please.</p>
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<p>Instead of using a blunt stick or object to clean up the jelled HHG I pre-position and clamp the bridge and surround with masking tape where the straight edges may be. What this gives me is an even better defined well for the rapid positioning of the bridge AND 2 minutes after the clamps are in place removing the tape removes roughly 90% or so of the glue in one felled swoop. Since the finish is still tucked under the bridge even if it's only .003 - .005"ish the risk of lifting loose finish with tape removal is greatly reduced. For the rest of the clean-up I wet a quality and soft paper towel (Bounty Select-a-size....) in the HHG water bath and push little damp pieces of the towel around the bridge/top junction with a slightly dulled tooth pick that may have also come with my pastrami sandwich.... You want the pieces of paper towel damp and never wet so as to not have water seep under the bridge...</p>
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<p>Lastly for now although HHG is truly wonderful stuff with examples of Egyptian furniture made with HHG and 2,000 years old surviving in museums HHG is not all that forgiving if one cuts corners.</p>
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<p>Preheating parts if you can't get the clamps in place in say 15 - 20 seconds is advisable and helpful as are dry runs and not in the gastronomical sense... Any method that we may develop to preposition clamps, cauls, etc when using HHG can save precious time. If the glue starts to jell before all things are as we want them it's compromised and 15 - 20 seconds is not a very forgiving amount of time.</p>
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<p>Again there are lots of ways to do the same task and likely more ways than any of us can think up too. Our methods morph and change regularly in our own quest to do great work and provide real value. I look back at some of the toots posted on my own web site and in most cases now what I once did I no longer do. And perhaps this is the attraction of Lutherie to me in so much as it's dynamic at least in the learning and a lifetime is not enough to even scratch the surface of all there is to know and learn.</p> Sure thing Nathan. I can't f…tag:fretsnet.ning.com,2013-07-04:2177249:Comment:1121262013-07-04T20:02:44.756ZHesh Breakstonehttp://fretsnet.ning.com/profile/HeshBreakstone
<p>Sure thing Nathan. I can't find my pics of our jig at the moment but here is a pic of Terry Kennedy's which is very similar to ours.</p>
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<p><a href="http://i252.photobucket.com/albums/hh38/terken1/Pettit%20Parlor/IMG_0971.jpg" target="_blank"><img src="http://i252.photobucket.com/albums/hh38/terken1/Pettit%20Parlor/IMG_0971.jpg" class="align-full"/></a></p>
<p>Sure thing Nathan. I can't find my pics of our jig at the moment but here is a pic of Terry Kennedy's which is very similar to ours.</p>
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<p><a href="http://i252.photobucket.com/albums/hh38/terken1/Pettit%20Parlor/IMG_0971.jpg" target="_blank"><img src="http://i252.photobucket.com/albums/hh38/terken1/Pettit%20Parlor/IMG_0971.jpg" class="align-full"/></a></p> Hesh, are you willing to shar…tag:fretsnet.ning.com,2013-07-04:2177249:Comment:1121252013-07-04T15:55:49.531Znathan clarkhttp://fretsnet.ning.com/profile/nathanclark
<p>Hesh, are you willing to share some pics of your ledge routing jig?</p>
<p>Hesh, are you willing to share some pics of your ledge routing jig?</p> It's best to score the finish…tag:fretsnet.ning.com,2013-07-04:2177249:Comment:1121242013-07-04T15:54:16.789Znathan clarkhttp://fretsnet.ning.com/profile/nathanclark
<p>It's best to score the finish around the bridge before removal. Failing that, it also works to clamp the bridge down located as precisely as possible on the original foot print then score the finish. OP, don't feel bad; bridge reglues on nicer guitars tend to be much easier than your current experience.</p>
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<p>FWIW, here is my non-basket case bridge reglue routine:…</p>
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<p>It's best to score the finish around the bridge before removal. Failing that, it also works to clamp the bridge down located as precisely as possible on the original foot print then score the finish. OP, don't feel bad; bridge reglues on nicer guitars tend to be much easier than your current experience.</p>
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<p>FWIW, here is my non-basket case bridge reglue routine:</p>
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<p><a rel="nofollow" href="http://fingerlakesguitarrepair.com/martin-bridge-reglue/" target="_blank">http://fingerlakesguitarrepair.com/martin-bridge-reglue/</a> </p> Thanks again Hesh. The bridg…tag:fretsnet.ning.com,2013-07-04:2177249:Comment:1119292013-07-04T14:57:37.957ZJack Lordhttp://fretsnet.ning.com/profile/JackLord
<p>Thanks again Hesh. The bridge I removed overlaid the finish by a good 1/4" on the back of the bridge, right where you need all the adhesion you can get. By the way, this is a Sigma guitar made by C.F. Martin in Korea.</p>
<p>Thanks again Hesh. The bridge I removed overlaid the finish by a good 1/4" on the back of the bridge, right where you need all the adhesion you can get. By the way, this is a Sigma guitar made by C.F. Martin in Korea.</p>