Official Luthiers Forum!
http://www.luthiersforum.com/forum/

Koa question
http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=22927		 Page 1 of 1
Author:  Bill Tolan [ Wed Jul 01, 2009 7:36 am ]
Post subject:  Koa question
My baby brother (53yrs old) lives in Hawaii, plays Hawaiian slack key style guitar and asked me to build him a guitar with Koa back and sides. I've built 9 guitars so far, so I'm not exactly a beginner, but I am still climbing that learning curve. I've done Mahogony and IRW back and sides, and have not approached any exotic/expensive wood such a Koa yet. (Gulp) If anyone has any suggestions about Koa and its quirks, I'd appreciate hearing. I plan on bending on a bending machine at around 300 degrees, wrapped in paper. I am not sure about a top yet - was thinking about Sitka. Don't know about binding wood - ebony maybe?
I plan on an OM size body.

So if anyone has any suggestions for me - including "don't do it you fool!" - I'd appreciate it.

thanks, Bill Tolan
Author:  Jim Kirby [ Wed Jul 01, 2009 7:59 am ]
Post subject:  Re: Koa question
Bill -

Although I've only bent koa with light figure, my experience so far is that it bends quite easily - as easily as EIR and probably a lot easier than the mahogany you have used. I don't think you need to get it up to 300 - it should give when steam starts to form if you are wetting it lightly.

Jim
Author:  peterm [ Wed Jul 01, 2009 9:01 am ]
Post subject:  Re: Koa question
Koa can be a little tricky. The more more figure the harder to bend. I wrap mine in kraft paper then wrap that in wax paper to seal in the steam. Bent at about 305. Careful getting too hot as Koa can easily scorch....and take it slow at bending.
Author:  George Thomas [ Wed Jul 01, 2009 9:55 am ]
Post subject:  Re: Koa question
I have built several guitars and ukes with koa. Ditto on the scorching - do be careful. For high figure koa sides SSII will probably help.
Author:  gozierdt [ Wed Jul 01, 2009 8:14 pm ]
Post subject:  Re: Koa question
I just completed a Koa OM with cutaway. The Koa had medium figure- from Bob C. I had trouble getting
kinks in the tighter inside bends, and lifted grain on outside bends at waist and in the cutaway. I did
extensive searches on bending methods after that, and bought a set of 0.015" spring steel slats for use in my fox
bender. I had also broken several pretty highly figured maple bindings before using the steel slats, but the
final set I did with the spring steel slats came out fine. I spritzed the wood, wrapped in spritzed brown paper,
then in aluminum foil. Bent at about 290-300 F. That last set of bindings came out fine. Haven't bent sides
using this method yet, but will be doing so on a high figure curly Narra set tomorrow. The theory on the spring
steel slats is that they support the wood much better. The downside is that they tend to spring back a lot,
so the inner slat must be constrained/held in the bent shape as you remove the wood. I worked up a way
to use finish nails and clamped wood blocks to hold the inner slat in place. If anyone's interested, I can get
some pictures tomorrow.
Author:  John Killin [ Wed Jul 01, 2009 8:45 pm ]
Post subject:  Re: Koa question
Koa also turns green when it reacts to some metals. I think I used aluminum flashing to bend a set and the sides had green spots when I was done. I was able to sand them out. I also used way to much water and had some serious cupping. Lots of lessons learned that day.

John
Author:  P@uL [ Wed Jul 01, 2009 10:46 pm ]
Post subject:  Re: Koa question
John Killin wrote:
Koa also turns green when it reacts to some metals. I think I used aluminum flashing to bend a set and the sides had green spots when I was done. I was able to sand them out. I also used way to much water and had some serious cupping. Lots of lessons learned that day.

John


i got some green from bending on a copper pipe as well. some were little spots and some were large patches of green. oh well it all sanded out :)
Author:  Bill Tolan [ Fri Jul 03, 2009 6:16 am ]
Post subject:  Re: Koa question
I've put in my order for the Koa - thanks for all the replies. Bill.
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/