Walnut bend

[mac007]

Hi
So this is the first time I tried walnut (straight grained) and for supposedly easy bend -it didn't work.
The first sandwich was spritz water, paper, foil heat blanket and iron strap. Has worked well before.
Heat blanket to 176 deg/off then start clamping.
Heat OFF.
Clamp waist then roll sides.

Cracked after cooldown.

2nd attempt-
More water sloshing the panel with a rag ie more water.
Better but still cracking.
I have enough for one more go.
Any suggestions appreciated

MK

[kiwigeo]

First question..how thick is that side?

When I was using blankets and forms for my bending I used to start the waist bend on a bending iron before sticking it in the bender.

These days I bend by hand. Im old fashioned and enjoy being in constant contact with the wood as it bends.

[mac007]

Thanks Martin

1.8mm as per TG

But I hear what you say and I'm thinking I'll start on an iron where you can get a 'feel'
Ken Parker does a similar thing in his archtop vids.

Cranking down on a bender doesn't provide much feedback.

Chrs

MK

[Dave M]

This is not going to help much but I found my American Walnut behaved fine. However I have a bender that keeps tension on both sides of the timber enabling that fairly tight cutaway. I am at around 1.8 mm and bend at about 120 C. Reasonably damp but not soaking.

Good luck D

[mac007]

Maybe some fabric softener???
Anyone had experience with this?
MK

[kiwigeo]

Maybe some fabric softener???
Anyone had experience with this?
MK

Ive used supersoft on tight bends.....it helps.

[56nortondomy]

I find walnut bends easy, I thickness to 2mm, at the cutaway section it's about 1.8mm I always use fabric softener. Cutaway sides I soak in hot water with fabric softener for about 25 minutes. Non cutaway I just spray with water and bend, I use aluminium slats for bending. Make sure your blanket is up to temperature before you start to bend. I bend at around 250f to 300f deg. Wayne

[Taffy Evans]

Hi, I have bent Walnut without issue, but then I have had mahogany slit on me.

I use the same sandwich setup but with a different heat source. I have heat bulbs in my bender heating from under the side pack with a blanket on the top of the pack under the top slat. I will also apply pre-heat to the waist area of the pack with my heat gun. I slowly add pressure to the waist, allowing the side to gain some heat from both sides. I stop before the waist bottoms out and work on the sides. when they are bent I complete the small amount of waist bend. Oh, and at times I have used a Veneer Softener spray but normally just water. I time my bending session so I can leave sides in the bender overnight.
This possibly will not help.
Cheers Taff

[mac007]

Thanks for all the replies- some interesting suggestions which I will try.

1/ Use an iron for the sharp shoulders
2/ try fabric softener
3/ Bend the outside curves first, then the waist

I have one piece to practice on then my last 2 sides of walnut.

I also feel that we (at my club) tend to bend the outside shoulder curves a bit too quickly- but then I have seen vids where people just pull the spring loaded cauls pretty much straight down as soon as the temp hits target.

Thanks again

MK

[Taffy Evans]

Hi again, I just came across these pics.
After the first failure, see the front side, I did what is seen in the next pic. To get the perfect bend out of the second set I wrapped the whole sandwich in foil as well. This pic shows the sides just taken out of the mould.

SAM_2314.JPG (134.63 KiB) Viewed 2943 times

SAM_2312.JPG (147.81 KiB) Viewed 2943 times

I did not waste the damaged side I made a thin-body acoustic.

1-SAM_3639.JPG (156.25 KiB) Viewed 2943 times

4-SAM_3646.JPG (91.13 KiB) Viewed 2943 times

But that's another story...
Taff

[mac007]

Thanks Taffy,

Yeah we routinely wrap foil/paper/wood.

I like your system of heating both sides tho'

MK

[Mark McLean]

Walnut usually bends easily. 1.8 mm is pretty thin, so should not fight you too much. Maybe that is just a difficult piece of wood?

[WJ Guitars]

When I bend sides on my bending machine generally temperature is set around 280 to 300 degrees F. Once the side bend is completed I reset the temperature controller to 260 degrees F and let it cook for 15 minutes. Then I switch the temperature control off and let it cool down to room temperature before removing the side bend from the machine. I found this method from a 'Blue Creek Guitars' YouTube on bending sides. So far I have had no cracking problems with when bending a vast range of of timbers including walnut using this procedure.

Wayne