Redo plastic sound hole binding

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Thomas Wentzel
Posts: 33
Joined: Tue Feb 28, 2012 4:21 pm

Redo plastic sound hole binding

Post by Thomas Wentzel »

Greetings..I'm working on a 30s Oscar Schmidt Stella guitar. Typically, the sound hole on these guitars is bound in plastic, and often it's shrunk over the years and sections need reglue. This example had been loose and repaired before, and working inside to reglue braces, I finally removed it before I caused more damage.

The binding ring is made up of a layer of white plastic and and thin (~.035") ebony veneer, as seen in the photo. As you can see, the ebony part of the binding did not come off cleanly, and some is on the plastic, some on the guitar top.

My Questions: Can anyone recommend a place to get thin ebony binding like this, or explain how to cut my own? I have a small bandsaw.

When re-attaching, should I first glue the ebony veneer to the plastic and then mount to sound hole, or glue the ebony first, and then the plastic ring?

Would it make sense to straighten (soak in hot water) the plastic first to glue the ebony veneer? If so, how would I re-bend once the veneer is attached?

I usually do trial and error when faced with new tasks like this, but, due to the fragile nature of materials, would like to have a procedure in mind before I bumble ahead..any ideas appreciated..
Tom
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BindingRing.JPG

Clay Schaeffer
Posts: 1438
Joined: Fri Jan 06, 2012 12:04 pm

Re: Redo plastic sound hole binding

Post by Clay Schaeffer »

I would rebind the sound hole with the ebony strip first and then apply the plastic. Although it is possible to bend thin strips of ebony, often what was used was maple dyed to look like ebony. There are also black fiber substitutes that are used in place of ebony, which bend much easier.

Darrel Friesen
Posts: 198
Joined: Fri Jan 06, 2012 5:48 pm

Re: Redo plastic sound hole binding

Post by Darrel Friesen »

Stewmac's has ebony purflings that I've used to bind soundholes with.

John Hamlett
Posts: 110
Joined: Thu Feb 02, 2012 10:59 am

Re: Redo plastic sound hole binding

Post by John Hamlett »

Stewmac also has dyed black maple purfling strips, and that's what I'd use. It is difficult to thin ebony to veneer thickness, and I think that is what you would have to do with their ebony bindings because I don't think Stewmac has thin ebony for purfling lines. I would glue the black strip and the plastic in the sound hole in one step, but as two pieces. In other words, laminate them together in place.

Thomas Wentzel
Posts: 33
Joined: Tue Feb 28, 2012 4:21 pm

Re: Redo plastic sound hole binding

Post by Thomas Wentzel »

...yeah, forgot to check stumac for the purfling..
Any suggestions as to glue? I use hot hide and LMI luthiers glue.
Clamping suggestions? ..thanks, Tom

John Hamlett
Posts: 110
Joined: Thu Feb 02, 2012 10:59 am

Re: Redo plastic sound hole binding

Post by John Hamlett »

I'd use "binding tape" and tape it in place. Stewmac sells tape for bindings, but it you have a good fit, masking tape will do. The "binding tape" it freezer tape, I believe.
I'd probably use Titebond (the LMI glue would be equivalent), unless I was going for historical accuracy. The short working time of hide glue would keep if from being my first choice.

Thomas Wentzel
Posts: 33
Joined: Tue Feb 28, 2012 4:21 pm

Re: Redo plastic sound hole binding

Post by Thomas Wentzel »

Thanks, John, tape sounds like an option, but I want to check the delicate shellac finish first. I was thinking blowing up a balloon in the sound hole?

Darrel Friesen
Posts: 198
Joined: Fri Jan 06, 2012 5:48 pm

Re: Redo plastic sound hole binding

Post by Darrel Friesen »

You're right John in that Stewmac doesn't appear to have thin ebony purfling. I was sure I got mine from them, but it may have been LMI or other. Anyway, the stuff I have is around 0.010". I never found a need to tape it in place once it was the correct length and ends butted together which held it tightly in the soundhole and then wicking in CA. Taping it wouldn't hurt though, just in case.

John Hamlett
Posts: 110
Joined: Thu Feb 02, 2012 10:59 am

Re: Redo plastic sound hole binding

Post by John Hamlett »

A balloon might work, if you can keep everything centered. A round, slightly tapered "plug" turned to fit might work too. it is true that an old, delicate finish can be damaged by tape.

Thomas Wentzel
Posts: 33
Joined: Tue Feb 28, 2012 4:21 pm

Re: Redo plastic sound hole binding

Post by Thomas Wentzel »

Thanks for the ideas .. the piece of original purfling is ~ .020, so the stu mac fits the bill. I'll see how it goes when I get it fitted in and decide on a clamping method..Tom

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