MIMF

Hello, I'm experimenting with making laminated sides. I have some nice basswood that I thought might work for an inner ply. I thinned some to 2.8mm/0.11" and bent it in my LMI bender. Here's the results, pretty bad.


Are there some approaches for bending softer woods with a bender?

Thanks,

-Eric

It needs to be thinner. About 0.080" should work.

Are you using an electric blanket? What do you do for adding moisture pre-bend?

Barry Daniels wrote: ↑Sun Apr 02, 2023 2:15 pm It needs to be thinner. About 0.080" should work.

Are you using an electric blanket? What do you do for adding moisture pre-bend?

Yes, I used an electric blanket. I lightly spritzed the wood and wrapped it in aluminum foil. I did the bending at 300ºF. 0.08" is about 2mm. Would it work even better a little thinner? I get this deformation a lot and I'm trying to figure out what I'm doing wrong. I got East Indian Rosewood to bend well on the first attempt but walnut, mahogany, and this basswood all end up like this to some degree.

How thin would you take the outer layer of the side? I have read where some even use wood that is 0.8mm/0.03" thin.

Thanks,

-Eric

For laminated sides I usually go with a 0.050" outer layer and a true veneer inside with a thickness of around 0.023". Fifty thou makes a very bendable layer.

One thing I discovered with aluminum foil is that folding the foil over the wood creates bunching and wrinkles that get telegraphed through the wood especially if it is thin wood. It is better to use individual pieces of foil on either side of the wood. This also allows the moisture to escape better.

Barry Daniels wrote: ↑Sun Apr 02, 2023 3:12 pm For laminated sides I usually go with a 0.050" outer layer and a true veneer inside with a thickness of around 0.023". Fifty thou makes a very bendable layer.

I'm going to aim for those numbers and see how it goes.

Barry Daniels wrote: ↑Sun Apr 02, 2023 3:12 pm One thing I discovered with aluminum foil is that folding the foil over the wood creates bunching and wrinkles that get telegraphed through the wood especially if it is thin wood. It is better to use individual pieces of foil on either side of the wood. This also allows the moisture to escape better.

That's a great tip!

Thanks,

-Eric

I've never successfully bent Basswood. I'm going to try Barry's numbers, too. I've often thought a veneer stack of 8, glued and bent and left to dry in the bender, would make good laminated linings for guitars worthy of Heavenly Angels. I'll probably try that.

Gilbert Fredrickson wrote: ↑Tue May 02, 2023 1:25 pm I've never successfully bent Basswood. I'm going to try Barry's numbers, too. I've often thought a veneer stack of 8, glued and bent and left to dry in the bender, would make good laminated linings for guitars worthy of Heavenly Angels. I'll probably try that.

After many trials I was able to bend basswood for laminations with no wrinkles or kinks. I have the LMI bender and I used just the long heating blanket, not the little waist one. Then I didn't wrap the basswood in aluminum foil and didn't use any water. This was what I thought was a silly frustrated move but it ended up working. There was a little discoloration from the spring steel but it mostly scraped off and was in an inner-layer lamination and wouldn't show. I also went much faster than I did with the walnut show layer. Easy and fast, and I hope it works as well for future projects.

-Eric

Eric,
I bend on a hot pipe, so my methodology may not directly translate....

I have been using Supersoft 2 for all my bending, these days Walnut and Curly Maple. The Curly Maple would facet, even with using distilled water, and it scorches if bent dry. I apply the SuperSoft 2 the evening before, applied liberally with a foam brush and layer like this:

plywood with about 35 lbs of weight per foot
Plastic sheet
brown paper
wood layer
brown paper
plastic sheet

I stack the side blanks and separate each layer with brown paper.

My pipe is 350 degF and I use distilled water in a spray bottle to keep the wood moist during bending.

I have not done full laminated sides, just upper waist sections to reinforce for Fishman Presys preamp installation .

I use Supersoft the evening before but I just stand the side up, leaning against my workbench, and let it air dry. Seems to work fine. No warpage issues.

These are great tips on successful ways to bend. Just to be clear though, what I was referring to was just for basswood laminations. I have yet to try some really difficult show-layer woods but that's coming. I'm saving these tips for then. Thanks.

-Eric