Side bending creases

[David Georgeson]

Hi, I'm using a side bending jig with solid forms for ukulele sides. I've used a combination of the sandwich stainless strips and heat blanket, with the blanket above or below the timber, but I'm getting creases in certain timbers at the waist. Wonder if any of you folks have an idea as to why this might be? I've combinations of ,more and less heat times, slower wind down of the waist press.

[demonx]

I had this happenin when I first started experimenting with timber I was flat sawing for practice/test bends.

The advice I was given was to use quarter sawn. I've never had a creased/buckled bend since.

[kiwigeo]

How thick are the sides?

[Allen]

Because ukes have much tighter bends than you get in guitars except for cutaways where they will be similar, the sides need to be thinned to about 1.8mm or even a bit less. .And even then it's quite possible to get bending creases.

Virtually every pro uke builder that I know has changed from bending solely with a solid form and blanket to hand bending to close to the finished shape and setting the bends on the solid form. It actually goes very quickly and you have far more feel for what the timber is willing to do, without having to make them perfect. They heat blanket and solid form take care of that for you.

[David Georgeson]

Thanks guys, I've been using 1/4 sawn timbers of 2 mm or slightly less, just a few different timbers have been creasing. I've taken Allen's advice and pre formed the sides on the bending iron, seems to have cured the problem. Thanks for your input.