Drill, impregnate with thin epoxy, drill again and
drive pins?
Thump
--- Farrell <mfarrel2@tampabay.rr.com> wrote:
> Comments below:
>
> > Terry Farrell wrote
> >
> > > >Arrrggggg! I have done that same technique on
> an old bridge as part of
> > > >refurbishing the bridge. I'd be afraid to do
> that on a new bridge. I
> > > >suspect there is always some resonable concern
> regarding how much epoxy is
> > > >absorbed into the wood and out of the void
> between pin and wood before the
> > > >epoxy hardens. My plan is to swab the hole with
> unthickened West System
> > > >epoxy and drive the pin into a normal tight
> hole.
> > > >
> > > >Terry Farrell
> > > >
> > 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.
>
> > > Ron Nossaman wrote:
> >
> > > I suppose it depends on what you think you want.
> If you think you want the
> > > pin bottomed in the hole, you can't use epoxy
> unless you arrange an escape
> > > route for the excess that will prevent the pin
> from bottoming - or blowing
> > > out somewhere else from hydraulic pressure as
> you drive it to full depth.
> > > That's going to be either an oversize hole, or
> drive it dry. If you think
> > > it isn't necessary for the pin to bottom in the
> hole, the epoxy can escape
> > > into the excess depth of the hole without making
> the hole oversize or
> > > blowing out elsewhere, or you can drive it dry.
> the one thing you can't do
> > > with an oversize hole is drive it dry, bottomed
> or not, and expect it to be
> > > functional.
> >
> > This is all true enough as far as it goes. I do
> use essentially oversized holes...
> > that is to say if the pinis just slim enough that
> it can be pushed in and taken
> > out dry with the fingers, then the holes are
> obviously oversized. The (very thin)
> > epoxy can find its way up the sides of the pin to
> form and allowed to form a
> > collar at the top. Clean off as necessary.
> Judicious use relative to the amount of
> > epoxy put into the whole limits overflow / waist.
> One little trick that takes care
> > of this and any bleed off into neighboring holes
> is to use a piece of piano wire
> > to gauge how deep the hole is... which tells you
> how much epoxy you need to drip
> > in. Pins being of the same length then will then
> end up << bottomed out >> in the
> > epoxy and will be one hundred percent solidly
> coupled to the bridge on all
> > surfaces. Cant hurt me thinks.
> >
> > 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
>
> > Getting a pin into an undersized hole
> > without damaging the wood in one way or another is
> a good trick, and one that it
> > would seem to me easily takes as much time and
> carefullness as dealing with the
> > kinds of problems the epoxy solution presents.
> >
> > When so many types of falsness are so easily
> curred by CA treaments, or epoxy
> > treatments, it seems to me like a good idea to
> begin this way. Especially when the
> > end result seems to last quite a bit longer.
> >
> > >
> > > So it seems to me that the first thing you need
> to decide is if you want
> > > the pin bottomed in the hole or not.
> > >
> > > Ron N
> >
> > This way you dont have to make that decision, tho
> the pin ends up bottomed out in
> > the epoxy. I'd like to know what this concern
> about the epoxy soaking into the
> > wood is all about tho.
> >
> > Cheers
> > RicB
>
>
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