Bending Macassar Ebony sides at what temperature?

[WJ Guitars]

I am planning to bend Macassar Ebony sides on my Fox bending machine using metal slates and heater blanket. The sides thickness is 2mm and for the cutaway side zone is thinned to 1.9mm. I normally spray water and paper wrap the sides. My question is what temperature should I use: 300 degrees F ? 330F ? or may be 360F ?.

My Bending Procedures:
Generally, I bend sides around 300 degrees F for eg. Blackwood and Rosewoods with no problems. I start bending from the waist when the blanket is around 230F to 240F and the waist ram is wound down to have a 9mm space. I then follow on bending the low bout to the tail and when the temperature is getting close to 300 degrees I complete the bend to the upper bout and neck end. I then wind the waist ram down to the metal slate and drop the temperature to cook at 260 F for 15 minutes. I remove the bended side from the bending machine when it cools to room temperature.

I would appreciate advise on a recommended temperature for bending Macassar Ebony.

Wayne

[nkforster]

I've no idea about temperature as I've never measured it.

But what I can offer that would be useful here is to soak the sides in a hot water with a cup of fabric softener for half an hour. Enough water to cover them, then weigh the side down so it doesn't float about. Wrap in baking paper and bend as normal.

For ebony, I'd be taking the whole side down to 1.8mm. And it must be sanded to 1.8mm, not planed.

[WJ Guitars]

But what I can offer that would be useful here is to soak the sides in a hot water with a cup of fabric softener for half an hour. Enough water to cover them, then weigh the side down so it doesn't float about. Wrap in baking paper and bend as normal.

For ebony, I'd be taking the whole side down to 1.8mm. And it must be sanded to 1.8mm, not planed.

Thanks Nigel for the information. I have been able to source orphan Macassar Ebony sides and I will use your method with a test run first.

Wayne

[kiwigeo]

Thanks Nigel for the information. I have been able to source orphan Macassar Ebony sides and I will use your method with a test run first.

Wayne

Yep..a test incineration is always a good idea

[TomBicknell]

And it must be sanded to 1.8mm, not planed.

For a newbie, Nigel, could you explain why sanding is better than planing?

[nkforster]

Planing leaves a smooth hard uninterrupted surface. Sanding effectively destroys the surface the depth of the grit. So a side sanded to 1.8mm has the stiffness of a slightly thinner side which is an advantage when bending. A side planed to 1.8mm has the strength of a 1.8mm side.

[TomBicknell]

That makes sense!

[56nortondomy]

Definitely use fabric softener on the cutaway side, i use it on all cutaway sides whatever timber I'm using. I've built one guitar with macassar ebony but it was years ago but I'm pretty sure i would've bent around 300f.
Wayne

[WJ Guitars]

Definitely use fabric softener on the cutaway side, i use it on all cutaway sides whatever timber I'm using. I've built one guitar with macassar ebony but it was years ago but I'm pretty sure i would've bent around 300f.

Thanks for the information Wayne. Surfing the internet: temperature information for bending Macassar Ebony ranged from 300F up to 360F. Some comments indicated that splitting was occurring at 360F. I was thinking around 300F as you have mentioned or may be slightly higher would be ok.

I have been fortunate so far on my other guitar builds when bending a cutaway side with NGR, EIR, Blackwood and Tasmanian Tiger Myrtle. I think it would be wise to use fabric softener as you and Nigel have advised.

For the test bending run I will use 300F on the orphan thinned sanded Macassar Ebony side.

Wayne

[56nortondomy]

Wayne i forgot to mention i thin my cutaway section down to around 1.7mm to 1.8mm slightly thinner than what you're thinking, but that's just me being cautious.
Wayne