This is a multi-part message in MIME format. ---------------------- multipart/alternative attachment Comments below: =20 > > > > > > > > Why would a (very) little epoxy absorbing into the wood be a = problem > > ? If the bridge pin is only a tad smaller than the hole, there will > > only be a small volume of epoxy filling any void space between pin = and > > wood. If the wood absorbs the epoxy, then there will be none or = little > > epoxy filling the void by the time it cures. Just a concern. >=20 > Hmm... I rather think that some serious absorbtion would have to be > going on for that to be a real concern. Course we cant actually look > inside the hole with the pin in there to see.... but on the other = hand, > pins so treated dont exhibit the same kind of falseness this = proceedure > porports to cure for very long periods of time. In fact, I have yet to > see this treatment fail over time, and I have seen mere pin = replacement > fail quite often. Please keep in mind that I am not saying this is a bad thing to do - but = rather just discussing concerns that have crossed my mind. As I said = before, I have used this same procedure myself when refurbishing an old = bridge. Epoxy will absorb into end grain quite readily. Take a block of = maple and liberally coat the end grain. Even a very thick coat will = usually absorb fully into the wood. When bonding endgrain to something, = I usually plan on having to coat the end grain several times to get the = endgrain saturated. In a bridge pin hole, two directions have end grain, = and hence the general concern. On a new bridge, I don't understand why you think it is advantageous to = drill a loose-fitting hole for the bridge pin, as opposed to a snug fit = - still swabbing the hole with epoxy on the snug fit. > > > As will every thing... practice makes perfect and you get the hang > > of how to > > > accomplish this one successfully fairly easy. But what I like most > > is the long > > > term. Seems to stay solid for like ever. Another thing to keep in > > mind with epoxy - it relies on a mechanical bond between wood and > > epoxy and between metal and epoxy. It is recommended by West System > > that when bonding with epoxy to metal that the metal surface be = sanded > > rough, coated with thin epoxy, and the epoxy sanded into the metal = for > > the most secure bond. A nice new shiny bridge pin is not likely to > > establish a good bond to epoxy. I can chip epoxy off any glossy > > surface real easy when I get waste on it - my floor, table top, > > etc. Terry Farrell >=20 > Yes, well we are not talking about bonding here. We are talking more = of > an alternative method of making for a tight fit for the pin. I dont = use > epoxy in bridge pin holes because I want to glue anything together. I > use it to make sure the pin is as solidly snug and supported as is > possible. It also seems to do a nice job of counteracting the effects = of > changing climates on the bridge pin holes, as I dont see these showing > signs of hole expansion through the years. Seems to be less of those > small cracks out from the pin that seem to always go nearly > perpendicular and slightly downwards from the string plane, but that > might be a biased perspective on my part... sometimes hard to tell = about > that kind of thing :) Again, just bringing up some thoughts. Some folks do think that a pin = will bond into the hole when using epoxy. There have been posts in the = past about concerns regarding difficulty of removing bridge pins that = have been epoxied into their holes. In a refurbished bridge, I think = epoxy is essential to fill voids in a poor pin/hole fit and to fill the = eye-corner cracks so common next to bridge pins. On a new bridge I don't = know that it is necessary, but it certainly can't hurt anything, and can = only serve to fill any small void related to drilling imperfections (on = a tight fitting pin), and to strengthen the wood immediately next to the = pin as some epoxy will be absorbed into the wood fibers. It seems to me that a standard tight pin/hole pin driven into an = epoxy-wabbed hole would be fully advantageous as it has the advantage of = traditional direct wood support, some frictional resistance to pin = movement and the benefits of epoxy, whereas a loose pin/hole fit would = only rely on the epoxy which does have some softness associated with it = - its not a brittle super-hard material. And please, this is discussion = - lets discuss apparent or potential advantages/disadvantages - as I am = only trying to seek out what appears to be the best method to install a = bridge pin. Terry Farrell > Cheers >=20 > RicB >=20 >=20 > -- > Richard Brekne > RPT, N.P.T.F. > UiB, Bergen, Norway > mailto:rbrekne@broadpark.no > http://home.broadpark.no/~rbrekne/ricmain.html > http://www.hf.uib.no/grieg/personer/cv_RB.html >=20 > ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/d0/68/d2/ce/attachment.htm ---------------------- multipart/alternative attachment--
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