Official Luthiers Forum!

Anyone out there ever use epoxy for gluing bracing? I've built a couple archtops and fitting the braces perfectly can be a real chore. Since titebond needs a tight fit to adhere properly, I'm wondering if epoxy might allow me better adhesion if there are any tiny gaps.

Troy, I think your idea is sort of a "band-aid" type fix. You'll be much better off in the long run to get a perfect fit the whole length of the brace, without haveing to press it into the plate at all. It should just sit in there and be perfect.
I know it's not such a pleasant task but it's an imprortant one.

I'm with Paul on this one. It's much better to spend the time to get
the braces fit well with little or no tension needed to get them to fit.

My first acrhtop I built with Brad Nickerson and I spent a good 2
days fitting the braces. Brad would come over from time to time and
tell me I was "getting closer".

We used chalk to figure out where my braces were contacting the top
and just kept scraping, filing and sanding until there was good
contact over the length of the brace.


Good luck and hang in there!!

Louis

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- Louis Freilicher

Oh No! Not another learning experience!

Hang on, I think you're reading me wrong. I'm not having to press the braces into fitting. When I lay the braces on the top there are no visible gaps. However, because of all the complex curves of the arched top, there could (conceivably) be a spot underneath the brace that doesn't make full contact with the top. I just figured that epoxy might fill any TINY voids (I'm talking less than paper-thin) and hold better than titebond.

A method I use is to stick on some mylar backed psa sandpaper (3M) where the brace is to be placed and slide the brace sideways in short strokes till you have a perfect match. remove the sandpaper and glue... It's a little messy
, but polyurethane glue (Gorilla) expands very well to fill gaps.

Dean

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Dean

Yes - epoxy is a great gap filler.

Just be sure that you add filler (fine sawdust, for example, or Cab-o-sil) to the epoxy first so that it doesn't flow out of the gap and into the wood and starve the joint. Add filler until the consistency is like ketchup, or even like jam.

And, if you value strength more than esthetics (or, if to you, they're the same thing) you can smooth any squeezed-out epoxy ( with a gloved finger) into a small fillet along the joint between the brace and the top. This is a common boat-building practice.


Phil

I like to spring my braces, so that they push upward on the top when they're glued in. Sort of pre-stressing them.

I would not trust Titebond for braces on an archtop. It's better than it's white glue cousins, but it will still cold creep, and allow the top to collapse from the downbearing pressure. Use hot hide glue.