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I’m needing to make a pretty tight bend with some maple binding but it just keeps breaking.
Any insights?
I need it for the end of a fretboard (the tongue if you will)
I even made a bending mold ha…
Heated to 300 but still snapped



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Have you tried a hot pipe with wet paper towel?

Thickness also makes a big difference. 2mm likes to split on the high runout parts of the curl, but 1.5mm doesn't put up a fight at all.

If all else fails, cut a curved piece from flat stock.

Sheet metal to act like slats in side bending would help.

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now known around here as Pat Foster
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http://www.patfosterguitars.com

My opinion: The key to success (if it can be had; some woods are just breakers) is to tightly support the outside of the bend, the convex side. This is why violin family builders use bending straps. You should try to use some thin metal on the outside of the bend, keep it snug, and bend it around a very hot pipe, well over 300F. See how that goes. If you don’t support the outside of the bend, a wood that is prone to breaking, like a figured maple, is just going to snap.

Along with the above suggestions about using a hot pipe at hot temperature (375+), I've had the best results bending both curly maple and curly koa by wetting only the inside surface of the wood. I've noticed that if the fibers at the top of a curl on the outside of a bend are wet, they tend to want to lift away from the wood which leads to cracking. Pre-treating with SuperSoft II helps too in my experience.

How thick is your binding? The binding I've bent was all 0.08" or less thick.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Another thing you can try is to cut two adjacent pieces at half the desired thickness and glue them back together in alignment when you bend them around the end of the fret board. You need a clear (high clarity hide) glue and some luck lining up the curl.

I would consider laminating it. Looks like you already have the inside and outside molds...

Cheers,
Bob


Edit,
I think that may be what Clay was staying...

Tell us a bit about your process? Those radii look like it should be a snap for maple, ahem, pun intended.

try boiling it that may will help
not sure how you were bending
you need heat in the process so how did you heat it in your mold, windex may help

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

That bend doesn't look too bad. I watched a Ken Parker archtoppery video yesterday, and he epoxies linen supports on the outside face of tight bends. Then bend on a form, with a metal strip support. After it is bent, he sets the bend with blankets and a form.
So you could glue on linen, pre bend on a pipe, and place in the mold you have.

I don't think that the mold itself will work. It would for lamination. It might with linen and a metal strip.

Good luck Snow.

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Why be normal?

Good points so far. I've found that simply gluing paper to the outside surface is a big help. A metal back strap can lose contact unless it's very flexible and you're putting all of the pressure on the strap, but paper that's been glued on is there. I've had good luck using CA or regular Titebond to glue the paper on. It's surprising how strong even regular copy paper can be.

I recently tried Alan's suggestion to glue paper on the outside when bending curly maple. It worked great.
Thanks Alan, I owe ya a beer.

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Say what you do, Do what you say.

Begs the question -- How do you get all the glue off when done bending?? Do residuals effect finish?

My experience releasing a titebond joint with heat was one gooey mess. I'm mystified how removing paper and glue post a heat bend would be fun at all. What am I missing? Add to that the hassles of removing glue before finishing and the problems residual glue can have there. Glue contaminated sides - inside or out - would be a problem for me.

Secrets of glue removal please.

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Brian R, Wood Mechanic
N8ZED

fish or hide glue in this case or just sand it off

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

In my opinion the above is not opinion but fact.

For a couple of years, the first thing I did at work every morning was wrap a pair of .100" thick, highly figured maple sides around a form for the nose and tight scroll of two Mandolins.
A few of spritzes of water from a plant mister and a wrap in brown paper so the aluminum form didn't stain the wood.

They pretty much NEVER failed. We had a piece of .008" spring steel under spring tension to back them up, but as Don said, Violin family luthiers do it every day too with a thicker metal strap and a pipe. HIGH PRESSURE right behind the point of contact with the hot form or pipe works wonders. Getting enough pressure is the secret.


PS: It's Nice to see the OLF seems to have retained it's relatively kind and humble spirit since the last time I was here!

Hey Dave, glad to see you're still out there!

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Steve Smith
"Music is what feelings sound like"

Thanks for the validation, David!

Not all skills associated with building violin family instruments will usefully transfer to building guitars, but bending by hand is one that will. Fox benders are useful, but not for everything.

Thank you all for the advice
I’ll definitely get it done. Part of the fun of making instruments is problem solving:)


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