Roger G wrote:
"The clean break was an indicator the epoxy didn't penetrate the wood as well as aliphatic resin such as Titebond. A good adhesion will pull wood fibers when separated."Correct! But you are incorrect that epoxy is not a good adhesive to use in a similar situation. One needs to use an appropriate epoxy in a correct manner. One often hears of folks using JB Weld - nothing wrong with JB Weld or similar epoxies, but a thick epoxy like that isn't going to adhere very well to the wood - as you point out in your case. One either needs to use an epoxy of appropriate viscosity with appropriate wetting-out properties, or use something like the West System two-step bonding method where unthickened epoxy is applied to both surfaces so it can soak in a bit and then the thicker gap-filling epoxy mixture is applied.
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Terry Farrell
Farrell Piano Service, Inc.
Brandon, Florida
terry@farrellpiano.com813-684-3505
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Original Message:
Sent: 01-13-2019 14:18
From: Roger Gable
Subject: Epoxy as a gluing agent?
I just completed re-gluing the upper plate to the vertical posts of a lyre. This lyre was previously "glued" using epoxy. Upon inspection, I noticed the break was extremely clean, as if from a mold. I have never advocated using epoxy as a gluing agent and this clean break justifies my reasoning. The clean break was an indicator the epoxy didn't penetrate the wood as well as aliphatic resin such as Titebond. A good adhesion will pull wood fibers when separated.
Roger
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Roger Gable
Gable Piano
Everett WA
425-252-5000
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