---------------------- multipart/alternative attachment In a message dated 7/30/02 11:30:39 PM Central Daylight Time, mfarrel2@tampabay.rr.com (Farrell) writes: > One clear thing I have noticed about CA glue is that it has little shear > strength. Take two flat pieces of wood. Glue the flat faces together with > CA (I would use thick or medium). After cure, just tap the end of one of > the boards while holding the other (so that you are applying a shear > stress) - they will break apart very easily. I often use this to my > advantage when making temporary jigs (like for locating bridges, etc.). > I haven't been able to follow much of this or any recent threads but this caught my eye. The fact that the shear strength is weak is why CA glue pinblock doping actually works. If the glue could really hold the pin, it would be stuck so hard and fast that it could only break when trying to turn it. Yet, the bond gives way on first impact but the material has still filled a gap and is nevertheless somewhat sticky. This sometimes makes for a good repair for loose tuning pins. This also is the reason why CA glue is good for repairing stripped screw holes. I usually put some glue in the stripped hole, dip the screw in the catalyst, then insert the screw. It goes in easily but within seconds, the glue is cured and initially, the screw is stuck. But one turn with a screwdriver and the initial bond is broken, leaving a filled gap and a sticky surface. The repaired screw hole often feels like it had been plugged with hard rock maple and redrilled. If a first attempt at this is less than satisfactory, then a repeat attempt will often work. One person asked me privately about restringing using CA glue as pin driving fluid. The same idea works here. If you are restringing a piano with pins that had a good feel, using CA glue as pin driving fluid will allow you to use the same sized pin again, avoiding the trauma to the pinblock of using over sized pins. One caution about doing the latter, cover your support jack with something disposable because some CA glue could run down and glue the support jack to the underside of the pinblock. But again, even in the event this happens, a good, sideways whack with a sledge hammer will break the bond instantly. Bill Bremmer RPT Madison, Wisconsin <A HREF="http://www.billbremmer.com/">Click here: -=w w w . b i l l b r e m m e r . c o m =-</A> ---------------------- multipart/alternative attachment An HTML attachment was scrubbed... URL: https://www.moypiano.com/ptg/pianotech.php/attachments/7c/43/cb/af/attachment.htm ---------------------- multipart/alternative attachment--
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