<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; = charset=iso-8859-1"> <META content="MSHTML 6.00.2800.1106" name=GENERATOR> <STYLE></STYLE> </HEAD> <BODY> <DIV><FONT color=#800080>Comments below:</FONT></DIV> <DIV> <BR>> Terry Farrell wrote<BR>> <BR>> > >Arrrggggg! = I have done that same technique on an old bridge as part of<BR>> > >refurbishing the bridge. I'd be afraid to do that on a new bridge. = I<BR>> > >suspect there is always some resonable concern regarding how = much epoxy is<BR>> > >absorbed into the wood and out of the void between = pin and wood before the<BR>> > >epoxy hardens. My plan is to swab the = hole with unthickened West System<BR>> > >epoxy and drive the pin into a = normal tight hole.<BR>> > ><BR>> > >Terry Farrell<BR>> = > > <BR>> Why would a (very) little epoxy absorbing into the wood be a = problem ?</DIV> <DIV> </DIV> <DIV><FONT color=#800080>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.</FONT></DIV> <DIV><FONT color=#800080> <BR></FONT>> > Ron Nossaman = wrote:<BR>> <BR>> > I suppose it depends on what you think you want. If you = think you want the<BR>> > pin bottomed in the hole, you can't use epoxy = unless you arrange an escape<BR>> > route for the excess that will prevent = the pin from bottoming - or blowing<BR>> > out somewhere else from = hydraulic pressure as you drive it to full depth.<BR>> > That's going to be = either an oversize hole, or drive it dry. If you think<BR>> > it isn't = necessary for the pin to bottom in the hole, the epoxy can escape<BR>> > = into the excess depth of the hole without making the hole oversize or<BR>> = > blowing out elsewhere, or you can drive it dry. the one thing you can't do<BR>> > with an oversize hole is drive it dry, bottomed or not, = and expect it to be<BR>> > functional.<BR>> <BR>> This is all = true enough as far as it goes. I do use essentially oversized = holes...<BR>> that is to say if the pinis just slim enough that it can be pushed in and taken<BR>> out dry with the fingers, then the holes are obviously = oversized. The (very thin)<BR>> epoxy can find its way up the sides of the pin = to form and allowed to form a<BR>> collar at the top. Clean off as necessary. = Judicious use relative to the amount of<BR>> epoxy put into the whole = limits overflow / waist. One little trick that takes care<BR>> of this and = any bleed off into neighboring holes is to use a piece of piano wire<BR>> to = gauge how deep the hole is... which tells you how much epoxy you need to = drip<BR>> in.  Pins being of the same length then will then end up << = bottomed out >> in the<BR>> epoxy and will be one hundred percent = solidly coupled to the bridge on all<BR>> surfaces. Cant hurt me = thinks.<BR>> <BR>> As will every thing... practice makes perfect and you get the = hang of how to<BR>> accomplish this one successfully fairly easy. But what I = like most is the long<BR>> term. Seems to stay solid for like ever. </DIV> <DIV> </DIV> <DIV><FONT color=#800080>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.</FONT></DIV> <DIV><FONT color=#800080></FONT> </DIV> <DIV><FONT color=#800080>Terry Farrell</FONT></DIV> <DIV> </DIV> <DIV>> Getting a pin into an undersized hole<BR>> without damaging = the wood in one way or another is a good trick, and one that it<BR>> = would seem to me easily takes as much time and carefullness as dealing with = the<BR>> kinds of problems the epoxy solution presents.<BR>> <BR>> When so = many types of falsness are so easily curred by CA treaments, or epoxy<BR>> = treatments, it seems to me like a good idea to begin this way. = Especially when the<BR>> end result seems to last quite a bit longer.<BR>> = <BR>> ><BR>> > So it seems to me that the first thing you need to = decide is if you want<BR>> > the pin bottomed in the hole or not.<BR>> ><BR>> > Ron N<BR>> <BR>> This way you dont have to make = that decision, tho the pin ends up bottomed out in<BR>> the epoxy. I'd = like to know what this concern about the epoxy soaking into the<BR>> wood is = all about tho.<BR>> <BR>> Cheers<BR>> RicB<BR></DIV> <DIV><FONT color=#800080></FONT> </DIV></BODY></HTML>