Gordon- When you say "cracked" I'm assuming you mean "separated," not "split." Cold hide glue is usually the restorer's choice in a situation like this. It will soften and combine with any hide glue that is in the joint. Hide glue is not gap-filling. (I just came from a great talk by Eugene Thorndahl, who has spent 50 years as a hide glue chemist. He said the gap-filling properties of hide glue are an Internet myth. <www.bjorn.net> He may be the only source of genuine graded hide glues for instrument and restoration work.) For a fast repair, consider CE (Cyano-epoxy aka Tech-Bond). It has the shear and shock resistance that CA sadly lacks, and sets a bit slower. Jim Coleman, Jr. and a few other specialty distributors sell it. In either case you may want to drill a hole for access to the joint and inject the glue right into the center of the problem. Ed Sutton -----Original Message----- >From: gordon stelter <lclgcnp at yahoo.com> >Sent: Oct 30, 2006 12:15 PM >To: Pianotech List <pianotech at ptg.org> >Subject: Re: Glue for cracked rib? ( Terry ????? ) > >Thanks, Terry. > I'm going to run some experiments with the other >glues, to "see what sticks". But I like your logic >about hide-to-hide ( although I think any water-based >glue will bind nicely with the hide glue, IMHO. One >thing that "came to me in a dream" is this: I have >the piano rolled up on its tail so the ribs are >horizontla, and WAS intending to drip super-thin CA >into the rib crack from the side ( the only type thin >enopugh to make it in there, probably ) with the >portion of the crack on the other side of the rib >"dammed up" with masking tape, to keep the CA from >just dripping though ( and all over the place ). But >then I rememberered that the glue on tape "activates" >the CA, so I might not have time to "pul it all >together" with the clamps. So I'll run some tests with >this. > 3 ribs are cracked ( so much for over-drying >boards! ) but only one crack is wide enough to get an >exacto-knife into. So I'm goping with the ultra-thin >CA< and leave it all clamped tightly together for >several dauys. > I'll let y'all know how it turns out. > Peace, > G > >--- Farrell <mfarrel2 at tampabay.rr.com> wrote: > >> The few times I've done this repair I have used cold >> hide glue. I figure >> there is still hide glue on the glue surfaces, so >> more hide glue would >> likely stick the best. It has good gap filling >> properties and is easy to >> use. I really don't see what would be better. >> Adhesives such as epoxy and >> others are only as good as your surface preparation >> - and there will be next >> to none with this repair. >> >> Terry Farrell >> >> ----- Original Message ----- >> > Thanks, Terry. >> > I just made some of these. But the question >> > remains: what glue? Bolduc? Epoxy? CA? I'm tempted >> to >> > try ultra-thin CA, simply because it is the least >> > viscous, and should wick into the rib crack well. >> > First I plan to blast out the crack in the rib >> with >> > brake part cleaner and one of those pipette tubes >> that >> > comes with it, as these is some residue in the >> rib >> > crack from stripping the board ( with straight >> acetone >> > ) that went through the soundboard cracks to >> below. >> > Then I'lll roll the piano on its tail so that the >> ribs >> > are horizontal, and glue dripped on the crack from >> the >> > side will fill it well. Then I'll put in the wire >> type >> > clamp, and waita few days. Question: I don't have >> any >> > CA accelerator, and none is sold in thios town. >> What >> > else might help it cure ? >> > If the wire doesn't want to come out, I'll >> try >> > heating it slightly. Heat softens cured CA> >> > An alternative ( that I've used to get glue >> into >> > tight spaces ) would to be to squeeze an exacto >> knife >> > blade into the rib crack, after drilling a tiny >> pilot >> > hole from above, poutting the drill bit back in to >> > make sure that the blade stops it, then drillinga >> > slighly larger hole ( like 1/8" ) from the board >> side, >> > and fliinig it with glue. With the blade still in >> > place, or with the intitial, smaller bit stuck in >> the >> > back half of the hole, glue can then be squeezed ( >> > witha hypo ) into the 1/8" hole, and the 1/8" bit >> > turned around and used as a piston to force it >> into >> > the joiunt. This works very well to get glue into >> > tight spaces. >> > What would you do? >> > Thump >> > >> > --- Farrell <mfarrel2 at tampabay.rr.com> wrote: >> > >> >> I have found using little boat clamps to be very >> >> useful for jobs like you describe: >> >> >> >> >> >> >> >> Plenty strong to pull anything together. >> >> >> >> >> >> >> >> Terry Farrell >> >> >> >> >> >> ----- Original Message ----- >> >> >> >> > I'm going to use a "piano wire tgrough the rib" >> >> type >> >> > clamp. Of course, I'll "dry run" it, first, too >> >> see if >> >> > it's strong enough to oull it back together. >> >> > G >> >> >> > >> > >> > >> > >> > >> >____________________________________________________________________________________ >> > Cheap Talk? Check out Yahoo! Messenger's low >> PC-to-Phone call rates >> > (http://voice.yahoo.com) >> > >> >> >> > > > > >____________________________________________________________________________________ >Want to start your own business? Learn how on Yahoo! 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