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Side Bending by Hand
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Author:  Col0320 [ Tue Jul 27, 2010 7:53 pm ]
Post subject:  Side Bending by Hand
I am very new to Ukulele building and am at the stage of bending the sides by hand using a Stewart MacDonald bending iron. I am practicing bending a very tight bend that is 1" in diameter and I am doing this on a curly maple wood that is 0.095" thick. I am soaking the maple for about 30 minutes and am waitin until I hear that "sizzle" and the wood seems to bend without forcing it.

The problem I am encountering is that the wood seems to "tear" along the grain of the wood. (I am bending with the grain.) Can anyone tell me how to avoid this tearing around the grain please. Is the diameter too tight for example or should I be choosing a different hobby?? laughing6-hehe
[uncle]
Author:  alan stassforth [ Tue Jul 27, 2010 8:01 pm ]
Post subject:  Re: Side Bending by Hand
well, that curly maple ain't easy to bend around a 1/2 inch radius.
what is that for, a uke with a cutaway?
or is it a super mini uke?
Author:  evanmelstad [ Tue Jul 27, 2010 8:12 pm ]
Post subject:  Re: Side Bending by Hand
My vote is too thick and too wet for figured maple. I'd try thinning down closer to 0.08", using a metal backing strip to support the bends, and using a spray bottle to wet the wood instead of soaking.
Author:  Col0320 [ Tue Jul 27, 2010 8:19 pm ]
Post subject:  Re: Side Bending by Hand
It's a Uke cutaway that I am trying to bend.
Author:  Tom West [ Tue Jul 27, 2010 8:53 pm ]
Post subject:  Re: Side Bending by Hand
Concur with Evan...!
Tom
Author:  DennisK [ Tue Jul 27, 2010 8:55 pm ]
Post subject:  Re: Side Bending by Hand
Yep, let it dry out and then spritz it just before pressing it to the pipe. Soaking tends to loosen the fibers so curly figure peels apart even more easily than if it's dry. But some steam does help it bend.

I'd probably go even thinner than .08 for the whole side, and thinner still in the area of the cutaway. Ukulele sides aren't that deep, and the tight bend should keep it from being too wobbly. Violin sides are usually less than .05, although those are even less deep than an ukulele.
Author:  Kevin Mason [ Wed Jul 28, 2010 9:26 am ]
Post subject:  Re: Side Bending by Hand
Even without the cutaway, .095 is too thick for ukulele sides. I would thin down into the .070s. Even though it is not very active at the moment, there is a wealth of information in the old threads of the Uke Talk builders forum.
Author:  Nate Swanger [ Wed Jul 28, 2010 11:26 am ]
Post subject:  Re: Side Bending by Hand
Just some things i learned while bending my first set of IRW sides a couple months ago.

soaking seems to just make it split that much easier, i ended up letting them dry and then just spraying some on the surface to help with scorching (this was thick practice curly maple sides from Stewmac)

keep moving, don’t try and perfect one section, work the tight bend first, run it along that area on the iron to get the entire section you are bending hot, it helps to prevent cracks, once you have that worked a little bit and the shape started, stop and work the upper/lower sections a bit, go back and forth trying to keep the whole sections temp up a bit.

you will have areas where fibers are in tension and then on the other side compression, a metal back strip helps keep the tension side from pulling apart or pealing up at run out. If you hear the first sounds of a crack STOP. you can work the area around it a bit but i would stop there and if possible fix with some thin CA. most of the cracks on the tight bends will be on the inside and you can fix with epoxy (that’s what i did on one of my sides).

the advantage i noticed to working the whole side was it helped me get tighter bends faster, I think it might have been that i ended up allowing the compression areas to merge with the tension area better by working the whole piece rather than the way i did the first side which was middle bout to the max! and then crack! ops, wasn’t bad though you can tell when its going to start, you hear a little pop.

Mine were straight grained IRW and i still found a way to start a crack in one of mine, curly is supposedly one of the more difficult woods to bend (i believe they don’t truly quarter it to get the figured, not positive so correct me if i'm wrong please).

any way that was my experience with my first set, take it with a grain of salt, what helped me may not help you.
Author:  Col0320 [ Wed Jul 28, 2010 12:25 pm ]
Post subject:  Re: Side Bending by Hand
Thanks to all for your advice. I am on the way to the shop to make the maple thinner and no more soaking. Thanks again you are all very kind with your advice. [:Y:]
:D
Author:  george wilson [ Wed Jul 28, 2010 5:53 pm ]
Post subject:  Re: Side Bending by Hand
You could make the area where the extreme bend is extra thin,like the sides of a violin (which are regularly bent to quite small radii) . Then,using a male and female mold,laminate another layer on inside the sides. The end of this lamination should be feathered out. It can be concealed by a cloth or wood vertical side reinforcement strip. I have done this of very tight bends. Use identical wood,and it will never show,and actually strengthens the cutaway.
Author:  es guitars [ Wed Jul 28, 2010 8:14 pm ]
Post subject:  Re: Side Bending by Hand
For tight bends on the iron Ive had luck putting a wet rag down on the iron then bending on that with the sides backed up with steel slats'

Brent
Author:  Loren Schulte [ Thu Jul 29, 2010 9:18 am ]
Post subject:  Re: Side Bending by Hand
Brent's right - use a rag and spritz the rag for more steam as needed. This method also greatly reduces scorching, especially on maple. Just keep the rag damp and try not to let it catch on fire!
Author:  Brock Poling [ Thu Jul 29, 2010 1:41 pm ]
Post subject:  Re: Side Bending by Hand
+1 on using a rag. on the tighter bends.

Also, think it down. On a uke I wouldn't go any THICKER than .08". Just about everything (except bubinga [headinwall]) bends ok if you get it thin enough and take your time.
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