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Having trouble bending my curly Koa binding. (Just doing some test bends right now). I've broken 3 pieces so far and can't seem to find that magic point. Spritzing the binding with water seems to help....and SEEMs to need heat above 235....but then scorches easily.
I also would like to add a maple strip to the edge. Should I CA the lamination to the KOA binding rather than use titebond so the heat doesn't delaminate when bending?

I'm just about ready to change to curly Maple binding instead.......and maybe rethinking my purchase of a Koa set for a future build if it's this tricky to bend.

Kent

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Wood Creations by Kent A. Bailey
EXCELLENCE IN SCULPTURE, CARVING, LUTHIER, ARCHITECTURAL MILLWORK AND DESIGN

http://www.kabart.com

Are you bending by hand on a hot pipe or using a Fox style bender?

Chuck

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"To live a creative life, we must lose our fear of being wrong"
- Joseph Chilton Pearce

I bend koa and snake wood all the time and not a problem. I have no idea of temps, because I don't use a thermometer so others that do that can comment. Light spritz, let get hot and bend normal rate. Is breaking while bending or after bend and taking out. When have broke it or seen it break at others it seemed was releasing waist before taking pressure of the upper bout.

Otherwise can only think not getting hot enough and if getting scorch to much water.

I use a hot pipe w/torch.
KB

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Wood Creations by Kent A. Bailey
EXCELLENCE IN SCULPTURE, CARVING, LUTHIER, ARCHITECTURAL MILLWORK AND DESIGN

http://www.kabart.com

Yes....breaks while bending and seems to be bending OK and easy....and then just snaps.
Kent

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Wood Creations by Kent A. Bailey
EXCELLENCE IN SCULPTURE, CARVING, LUTHIER, ARCHITECTURAL MILLWORK AND DESIGN

http://www.kabart.com

I use a fox style bender so can't help you on that. I bend my purfling and glue it when installing the binding as easier for me with the miters. Probably wrong, but has worked well over the years. I do bend on pipe on occasion (very very few though) but like with fox thing, I bend 4 or 5 at a time and not singles

Maybe I posted the other question unclearly. I also want to add a maple laminate strip to the KOA binding bottom for a side accent and want to know if I should CA it or titebond it. I'm afraid it may delaminate when heat bending if I use a white glue or titebond.
Kent

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Wood Creations by Kent A. Bailey
EXCELLENCE IN SCULPTURE, CARVING, LUTHIER, ARCHITECTURAL MILLWORK AND DESIGN

http://www.kabart.com

I understood what want to do. As far as glue don't know, don't use any for that particular part until I am installing binding on wood bindings. I do if doing plastic but then whole different thing as far bending around body.

I think either will work Kent. I use Titebond II and I get no delaminations when bending. I do mine on a hot pipe also.

As for the koa, I get my best results when I am pulling the bends from far away from the fulcrum point. I hold the ends of the binding piece maybe 5-6 inches away from the pipe top and pull out as much as down. That greatly reduces the koa to want to snap. Some koa is very very prone to scorching and other pieces won't scorch at all, I don't understand that but I have seen it many times. I regularly bend .06 curly koa into 2" circles for earrings and I feel like I have a good feel for it. every once in a while though there is a piece that just will not take the bend. Usually there is just too much runout and you get that telltale diagonal snap. In general I would say that koa, even the curly stutff, is one of the easiest woods to bend. I am sorry you are having trouble with this batch.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

How thick is the binding? It's alot easier to bend at .060" than it is at .080". I cut a .070" channel for the .060" binding, then scrape the sides down flush with the bindings. I usually pre glue my purflings with CA.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

my binding is .075. I have a feeling it is a runout issue. This binding also wants to twist in sections.
KB

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Wood Creations by Kent A. Bailey
EXCELLENCE IN SCULPTURE, CARVING, LUTHIER, ARCHITECTURAL MILLWORK AND DESIGN

http://www.kabart.com

I had the same sort of trouble with koa bindings. I got some very good advice on Delcamp's classical luthiers site. See:
http://www.delcamp.us/viewtopic.php?f=1 ... oa+binding
Good luck.

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http://coneryguitars.com

Kill your television!

Runout can cause problems bending. I prefer to make my own binding to (try to) eliminate runout. Again. .060" will bend ALOT easier than .075" Unless it's something really figured, or hard to bend I can put .060" bindings on a dread without pre bending. I don't have the nerve to try on anything more curvy than a dread.

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I didn't mean to say it, but I meant what I said.
http://www.brackettinstruments.com/

Bailey: Have not used Koa but have used very high curl Maple.I glue perfling to the binding before bending using titebond and have only had one delam in doing quiite a few strips. I put the purfling back to back and tape the two strips together.This gives the purfling some support when bending and essures I bend a pair rather then two of the same.I put up to four of these sets in a bender dry and turn the heat on and keep trying for ease of bending,when they start to bend easy at the waist I tune the heat down to about half way,do the waist and quickly bend the two bouts.Sorry I don't have any temps.as I bend everything by feel. Hope you have some success.
Tom

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A person who has never made a mistake has never made anything!!!

Problem with curly woods is that it's chock full of short grain.

I use a bending form and do it just like sides, light spritz, kraft paper wrap, blanket, and slats. I've had much better luck this way with curly woods.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com