Providing "Tooth" When Gluing - FRETS.NET2024-03-28T14:20:52Zhttps://fretsnet.ning.com/forum/topics/providing-tooth-when-gluing?commentId=2177249%3AComment%3A57166&feed=yes&xn_auth=noSorry to intentionally bump a…tag:fretsnet.ning.com,2011-05-30:2177249:Comment:581672011-05-30T16:59:42.459ZMike Kolbhttps://fretsnet.ning.com/profile/MikeKolb
<p>Sorry to intentionally bump a dying thread, but I found this instruction sheet from StewMac that came with my set of "toothing irons" purchased maybe in the late-90's or so. </p>
<p>Interesting that they no longer sell them, perhaps for the reasons that we've agreed-upon here? Anyway, just for yuks...…<a href="http://storage.ning.com/topology/rest/1.0/file/get/2167736310?profile=original" target="_self"><img class="align-full" src="http://storage.ning.com/topology/rest/1.0/file/get/2167736310?profile=original" width="369"></img></a></p>
<p>Sorry to intentionally bump a dying thread, but I found this instruction sheet from StewMac that came with my set of "toothing irons" purchased maybe in the late-90's or so. </p>
<p>Interesting that they no longer sell them, perhaps for the reasons that we've agreed-upon here? Anyway, just for yuks...<a href="http://storage.ning.com/topology/rest/1.0/file/get/2167736310?profile=original" target="_self"><img src="http://storage.ning.com/topology/rest/1.0/file/get/2167736310?profile=original" width="369" class="align-full"/></a></p> Frank, FWIW, the University o…tag:fretsnet.ning.com,2011-05-25:2177249:Comment:578432011-05-25T15:02:53.758ZGeorge Robertshttps://fretsnet.ning.com/profile/GeorgeRoberts
<p>Frank, FWIW, the University of Michigan guitar has the back scored with tooth marks under both the neck and tail blocks, and even under the kerfing. May be just another instance of "If a little is good, more is better."</p>
<p>George</p>
<p>Frank, FWIW, the University of Michigan guitar has the back scored with tooth marks under both the neck and tail blocks, and even under the kerfing. May be just another instance of "If a little is good, more is better."</p>
<p>George</p> An interesting observation, F…tag:fretsnet.ning.com,2011-05-24:2177249:Comment:583912011-05-24T16:19:07.825ZGreg Mirkenhttps://fretsnet.ning.com/profile/GregMirken
An interesting observation, Frank. I've never heard it posited that toothing has nothing to do with the strength of the joint, but rather maintaining alignment of the parts while clamps are applied. That would explain why some joints were routinely toothed while most were not.
An interesting observation, Frank. I've never heard it posited that toothing has nothing to do with the strength of the joint, but rather maintaining alignment of the parts while clamps are applied. That would explain why some joints were routinely toothed while most were not. I've heard it said that "toot…tag:fretsnet.ning.com,2011-05-23:2177249:Comment:582862011-05-23T20:37:09.487ZFrank Fordhttps://fretsnet.ning.com/profile/FrankFord
<p>I've heard it said that "toothing" the surfaces helps in keeping the parts in alignment as the clamping pressure is applied. That may be why we see those marks on old glue joints where alignment is critical and no fixturing was used. The most stressed joints of a guitar, for example, are the center joints of the top and back, and you never hear talk about roughing them. Additionally, there aren't toothing marks on other joints, such as neck and end blocks.</p>
<p> </p>
<p>I've heard it said that "toothing" the surfaces helps in keeping the parts in alignment as the clamping pressure is applied. That may be why we see those marks on old glue joints where alignment is critical and no fixturing was used. The most stressed joints of a guitar, for example, are the center joints of the top and back, and you never hear talk about roughing them. Additionally, there aren't toothing marks on other joints, such as neck and end blocks.</p>
<p> </p> Thanks to everyone for all th…tag:fretsnet.ning.com,2011-05-21:2177249:Comment:578032011-05-21T22:42:00.686ZGeorge Robertshttps://fretsnet.ning.com/profile/GeorgeRoberts
<p>Thanks to everyone for all the input.</p>
<p>I have always added tooth to the backs of ebony bridges using a sharp rasp in the same direction as the grain. Never even considered doing it to a spruce top.</p>
<p>As a dyed in the wool traditionalist, I'll probably continue the same with the ebony bridges, hoping that Paul is right and that "those old guys were on to something."</p>
<p>George</p>
<p>Thanks to everyone for all the input.</p>
<p>I have always added tooth to the backs of ebony bridges using a sharp rasp in the same direction as the grain. Never even considered doing it to a spruce top.</p>
<p>As a dyed in the wool traditionalist, I'll probably continue the same with the ebony bridges, hoping that Paul is right and that "those old guys were on to something."</p>
<p>George</p> Toothing and using a solvent…tag:fretsnet.ning.com,2011-05-18:2177249:Comment:576972011-05-18T22:49:05.000ZRussell Vancehttps://fretsnet.ning.com/profile/RussellVance
Toothing and using a solvent to remove extractives/contamination are two entirely different things: cleaning with acetone or similar conditions the wood for a good wetting action for the glue which allows both the adhesive bond and mechanical bond to be optimized. This is entirely different from "toothing" which facilitates a better mechanical bond than would otherwize be gained. Toothed wood should be cleaned just the same as planed wood. R.
Toothing and using a solvent to remove extractives/contamination are two entirely different things: cleaning with acetone or similar conditions the wood for a good wetting action for the glue which allows both the adhesive bond and mechanical bond to be optimized. This is entirely different from "toothing" which facilitates a better mechanical bond than would otherwize be gained. Toothed wood should be cleaned just the same as planed wood. R. When I've come across scratch…tag:fretsnet.ning.com,2011-05-18:2177249:Comment:576252011-05-18T19:55:07.846ZRich Middendorfhttps://fretsnet.ning.com/profile/RichMiddendorf
When I've come across scratching/grooving on old ebony bridges and rosewood backs I assumed it was because they are oily woods which provided poor bonding surface. I usually swipe rosewood or ebony with a bit of acetone on a rag to get a good bond, so toothing isn't really necessary.
When I've come across scratching/grooving on old ebony bridges and rosewood backs I assumed it was because they are oily woods which provided poor bonding surface. I usually swipe rosewood or ebony with a bit of acetone on a rag to get a good bond, so toothing isn't really necessary. Hammers are certainly dangero…tag:fretsnet.ning.com,2011-05-17:2177249:Comment:573512011-05-17T17:56:04.483ZHoward Klepperhttps://fretsnet.ning.com/profile/HowardKlepper
<p>Hammers are certainly dangerous in the wrong hands. </p>
<p><a rel="nofollow" href="http://www.printculture.com/item-649.html" target="_blank">http://www.printculture.com/item-649.html</a></p>
<p> </p>
But the difference is that using the toothing tool as directed will not improve the joints for which it is intended.<br />
<p> </p>
<p>Hammers are certainly dangerous in the wrong hands. </p>
<p><a rel="nofollow" href="http://www.printculture.com/item-649.html" target="_blank">http://www.printculture.com/item-649.html</a></p>
<p> </p>
But the difference is that using the toothing tool as directed will not improve the joints for which it is intended.<br />
<p> </p> Pretty much agree and would l…tag:fretsnet.ning.com,2011-05-17:2177249:Comment:576132011-05-17T16:21:39.318ZRussell Vancehttps://fretsnet.ning.com/profile/RussellVance
<p>Pretty much agree and would like to add the usual fly in the ointment stuff - a lot of small shop/hobby luthiers do not have access to shear planing jointers - ordinary jointers, particularly those of the larger production shops tend to beat down and burnish/locally case-harden wood surfaces and a burnished surface is detrimental to the gluing process. Similarly, not everyone is capable of machining or planing surfaces dead flat and true. </p>
<p>Franklin, which makes Titebond is very clear…</p>
<p>Pretty much agree and would like to add the usual fly in the ointment stuff - a lot of small shop/hobby luthiers do not have access to shear planing jointers - ordinary jointers, particularly those of the larger production shops tend to beat down and burnish/locally case-harden wood surfaces and a burnished surface is detrimental to the gluing process. Similarly, not everyone is capable of machining or planing surfaces dead flat and true. </p>
<p>Franklin, which makes Titebond is very clear about this in their tech application sheets.</p>
<p>The procedure for overcoming a burnished surface is to hand plane it (which in the case of ebony fingerboard backs is a difficult operation if you wish to keep the glue surface dead flat - which is a basic requirement for a good joint) or remachine it with a shear cut/helical head jointer (or shear cut rotary planers found in some of the large shops - sort of a big version of a safe-t-planer attachment) which will present clean, flat wood for the glue to act on.</p>
<p>Modern gluing procedures and practices have evolved as the finishing systems and accuracy of new systems have improved. Toothing still has a place in exposing some useful surface, 'closing-up' a bad joint and allowing extractives to be cleaned where this modern level of finishing is unavailable. Toothing did/does sterling service in the assembly of high end pianos. Sanding a surface prior to gluing is, among other things, simply a finer method of toothing. </p>
<p>As Howard points out, the molecular component of gluing is predominant over the mechanical bonding component in general gluing procedures we use, however, the mechanical bonding provided by sanding or toothing may well come in play more significantly if the surface being glued is burnished, not flat or poorly dimensioned - in which case toothing may be of more assistance than detriment (a detriment otherwize directly related to a small decrease in useful surface area for the molecular bonding taking place) .</p>
<p>Epoxy joints are used for specific purposes and have different applications and limitation that other common adhesives.</p>
<p>And finally, Stewmac also sells hammers, which can do a lot of damage in the wrong hands, but it is probably not a mistake to sell them.</p>
<p>Rusty.</p> Paul, what a great tool/tip!…tag:fretsnet.ning.com,2011-05-17:2177249:Comment:571722011-05-17T01:29:25.081ZKerry Krishnahttps://fretsnet.ning.com/profile/KerryKrishna
<p>Paul, what a great tool/tip! Thanks for posting this..</p>
<p> </p>
<p>Paul, what a great tool/tip! Thanks for posting this..</p>
<p> </p>