What causes tailpiece rattling ?

anthon_74

Hey friends,
The tailpiece on my DG 300 recently started rattling when I play. Is repairing this as simple as buying a new tailpiece, or is it possibly have something to do with how it's attached. I would hate to buy a new one and still have the same stupid problem. From a basic visual analysis, I can't see how it's happening.
I know it's the tailpiece by the way, because I can make it stop by stuffing tissue under it. Unfortunately, that also greatly diminishes the sound quality.

anthony

Craig Bumgarner

A couple things to check right off the bat:

There should be a piece of felt under the tailpiece where it goes over the edge of the top. It should extend inward far enough so that nothing but the felt is touching the top.

Check the insert. This is usually ebony and has slots around the edges to slide onto the metal work. The insert could be rattling in the slots. You can probably dampen it by just pressing down on the insert while testing. If this is it, remove the tailpiece, slide the insert out and do what you need to to make it more secure. Maybe a little silicon sealant or DAP caulk (black).

Check for loose string studs. If tissue under the tailpiece stops it, try holding the tailpiece is various places to dampen the vibration. If that doesn't do it, do the same to the top around the tailpiece. Sooner or later, you'll hit the thing that is doing it.

Bob Holo

Typically it's the insert rattling in the brass. The wood shrinks, particularly this time of year, and becomes loose as it no longer grabs the brass as intended.

There are many things you can do to fix the rattle - dabs of rubber cement around the edge (underside... take the tailpiece off and do it on the underside if dabs of glue bother you) Or for a more permanent fix, you can glue it with more permanent glues, or even put leather across the back. I've seen many ways of doing it. But then again, that rattle, if it happens seasonally, is a canary in a coal mine. It might be telling you to humidify, particularly if the guitar sounds reverberant or pingy as they often do when they get too dry.

ChrisMartin

Just a warning regarding Craig's suggestion to use silicon
sealant. I would recommend NOT doing this as it will leave traces that no amount of acetone cleaning can ever completely remove, so if it does not do the trick and a stronger adhesive is required the silicon contamination will prevent any adhesive from sticking to the required surfaces. I always try to avoid using silicon based products for this reason.

Craig Bumgarner

That's a good point Chris. We work with silicon a lot in my day job at the boatyard and I thought about the silicon contamination issue when I suggested it, but figured the silicon would likely do the job well from both adhesion and dampening, but you are quite right, gluing with something else afterward is difficult.

Honestly, what I use for inserts when one needs tacking down is SikaFlex marine one part polyurethane sealant, but I figured this might not be readily available to everyone.

Bob's suggestion of rubber cement is a good one. DAP caulk is still a good option I think. Plain old white or yellow glue (Elmers, Titebond) would probably work okay too. It doesn't take much whatever you use, this is not a structural problem, just trying to secure the insert so it does not rattle.

Jazzaferri

At your local auto paint supply specialist you can obtain Silicone polish remover.

Wear proper no VOC mask and gloves and eye protection. Works a treat but don't ge t any on a finish you want to keep.

Craig Bumgarner

What's the purpose of the insert anyway? Seems like a fair amount of work and weight just for decoration. Does the added mass provide a more solid counter poise to the string vibrations? Does the added mass noticeably dampen things in some way? Anyone ever try taking the insert out to see how it sounds? I'll have to try that next chance I get. Assuming it is well made and installed, does a tailpiece affect the sound noticeably? Humm....

Bones

How about just a tiny little bit of hot melt glue along the groove where the wood meets the brass to adhere and dampen???

Jazzaferri

Maybe dampen sympathetic vibrations?

Al Watsky

Wow. Listen. Its a decorative element on a fitting. It should be glued by the person assembling the instrument as a matter of course. What it is glued with is not particularly important as long as its inert and dries completely . In a shop environment there are many glues available , but one thing I am reasonably sure of is that there is no reason that any musical instrument that has ever been made , or that ever will be made should have caulking or hot melt glue on it. Cyano, Hot hide, epoxy , fish glue are all possible , there is also the possibility of flexing the metal with the insert removed to put tension in the assembly which will keep the decoration from vibrating . Or crimp the edges of the contact points. :')
I like leather under the tailpiece. Felt is traditional which is fine if its thick enough but leather actually protects the binding more effectively and does not fray . You can get red or green polished split hide from a leather or fabric supply house.

Craig Bumgarner

Fair enough, I like the crimping idea.

As far as being only decorative, that's heretofore been my supposition, but every other decorative element of a traditional acoustic guitar I can think of has some functional purpose that underlies it. Well, there are those nails and rhinestones Busato used on the headstock and pick guards :-), but all the traditional elements have a functional basis. The rosette keeps the top from splitting around the soundhole, for instance. The insert just seems like too much trouble to be solely decorative. If they wanted decoration, why not just stick something on or include it in the stamping process.

I'll do a little testing this weekend and come back.