Tape on the back for testing

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Craig Bumgarner
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Tape on the back for testing

Post by Craig Bumgarner » Sun Jan 11, 2015 10:04 pm

In a recent thread, Jeff (jeffhigh) mentioned:

"I could do like Brian Burns and tape the back on, glue on the bridge, test and modify."

Does that actually work? Is the connection to the sides solid enough with tape to get a reliable test of the closed box?

I glue my tops to the sides first so I can play with top mobility before closing, but would like to tune the back stiffness more accurately and with the small sound holes on most Selmer guitars I can't reach in to shave a brace. I've taken more than one glued back off to adjust. If tape would resemble glue for testing, that would be a huge game changer for me.

It sounds easy enough and I'll test it for sure next build. Trevor mentioned the time it took. How so?
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Trevor Gore
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Re: Tape on the back for testing

Post by Trevor Gore » Mon Jan 12, 2015 6:54 pm

Craig Bumgarner wrote:Does that actually work?
Brian makes it work. It relies on having a back cut exactly to size and taped such that there is no air leakage. Brian is pretty amenable, so perhaps give him a call to get all the details.

Compared to removing a glued on back for adjustments, I don't think the time issue will be significant for you!

Craig Bumgarner
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Re: Tape on the back for testing

Post by Craig Bumgarner » Tue Jan 13, 2015 12:22 am

Trevor Gore wrote:Compared to removing a glued on back for adjustments, I don't think the time issue will be significant for you!
You must be better at it than I. My backs are laminated and the hot knife tends to wonder into the first laminate (mahogany) and splits the laminate in places. Makes more a mess of it than I would like. In my removals, the back has already been trimmed to the sides and the glue fairly will set. My guess is it would be easier if I left an overhanging edge to guide the hot knife and, of course, do it will the glue has just started to set. I use Titebond for backs and understand the 15-20 minute idea.

I still might have a go at the tape idea, just to see how it works. I'll try to contact Brian as well. Thanks.
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Trevor Gore
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Re: Tape on the back for testing

Post by Trevor Gore » Tue Jan 13, 2015 8:35 am

:D

I think we got our lines crossed there, Craig!

What that was supposed to mean was that using tape will make removing a back a lot faster than if you used glue, so the time that using tape takes will not be a significant issue for you.

Craig Bumgarner
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Location: Drayden, MD, USA

Re: Tape on the back for testing

Post by Craig Bumgarner » Wed Jan 14, 2015 12:02 am

Thanks for the uncrossing the wires! I'll let you know how it goes.
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kiwigeo
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Re: Tape on the back for testing

Post by kiwigeo » Wed Jan 14, 2015 3:06 pm

If you plan to get backs off then a photographers sealing iron is a useful tool. I used mine alot during my lute build both during top and back glue up as well as removal.

http://www.amazon.com/Hangar-9-Sealing- ... B0006N6Y0Q
Martin

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