Hi Everyone,

While doing a thorough cleaning on the inside of my current project piano I discovered a couple of very small cracks around a couple of the bridge pins on the treble bridge. These are very minor cracks (each crack only affects one pin and no pin displacement is evident) so I believe a repair of filling the cracks with epoxy should be in order.

Is there a specific type of epoxy that works well for this job? Reblitz isn't very specific in his book and I am hesitant to use the commonly available 5-minute epoxies.

Thanks,
Steve

I like West System epoxy, but for hairline cracks I would be inclined to treat them with thin CA glue.

Thanks Ryan.

I may have a go at these with CA as the cracks definitely fall into the hairline category. They weren't even visible until I cleaned the dust off the bridge and the bridge pins were still tight after I removed the strings.

That's the time to catch it! Kill it before it grows.

My thinking exactly. I injected some CA into all three of the cracks this afternoon and it seems to have set up nicely. I'm going to give it a day or so to cure and then put the strings back on to see if the glue holds when under pressure.

CA is pretty brittle and becomes pretty hard, to me it does not feel exactly right for ths job. How did it work out?

Don't let Rod Vernjack know what you're doing. He doesn't like to remove epoxied pins on rebuilds. Neither do I, but Rod's pretty vehement about it.

SUffice to heat they; but epoxy seem to be not hard enough or anyway to damp the tone a little. occasional Ca on a poor bridge pin does not make me cry !

I found the same situation in a five-year-old grand in a restaurant, where they wet-mop the tile floor underneath every day. I measure the pitch of every A before tuning, and octaves 5 and 6 were going out the fastest (and had the worst unisons). I looked closely, and sure enough, the pins were moving in the cracks in those octaves. I used thin CA. I know it's possible to get water-thin epoxy as well, but I don't have it. This can also help one possible cause for false beats.

--Cy--

With the exception of some thicker gel type CA's, CA glue has very little fillers. I use thin CA on fine hairline cracks to help stop them from continuing to grow. If the crack is big enough to fit the tip of a fine sewing needle in, I will douse it with thin CA first. After it dries, I will follow up with thin epoxy working it in with a fine needle to fill the gap. Hobby stores are the best place to procure quality epoxy in smaller quantities, stay away from any clear epoxies that may have slightly yellowed from age.

I think you should leave it alone. It is not necessarily going to get worse, which may not be the case if you mess with it.

If your going to epoxy new pins in a bridge that's fine if that is what your needing to do.

It is a very good idea to take the new pins put them into a zip lock bag and spray some Teflon spray into that bag. Shake it up and let dry.

One day when some poor rebuilder needs to take them out, they will come out, still with some difficulty but without breaking off pins and limbs.

It's funny how many bridges I see with hairline cracks during rebuilds, and the pins are TIGHT when I try to remove them. I'd second the suggestion to leave them alone until things get really loose.