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I will be performing some side bending testing in the near future. I am curious what are the most difficult woods to bend? Does anyone have any stray sides they would be willing to part with cheap to help with testing?

Thanks!

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Brad
Avon, OH

I don't have much experience but I've heard that Bubinga is one of the hardest to bend. I've also heard that always can be bend without problem, ou just have to have the right temperature, the right humidity, the right pressure, etc, etc...

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Francis Richer, Montréal
Les Guitares F&M Guitars

So far for me... Whatever flavor of miscellaneous Brown "African Mahogany" I ended up with at the Woodcraft store is the worst bending wood in the World..

The strange part is that I have used African Mahogany before, and not had any trouble what-so-ever....

*Grumble*

Here was Side #1 -- using technique that normally bends most everything just fine...


Here was Side #2 -- Gosh, maybe it wasn't hot enough... I will run it up past 375F and let it cook all the way thru...


It still wouldn't relax... It was breaking everywhere.. up to the point when it literally turned to charcoal inside the tin foil.

Here are Sides 3 and 4 -- Bent at 0.065" thick... glued up after 3 rounds of re-heating and overnight setting up.... Still spring back like mad... Where did that waist go?


*Sigh*

John Hall is right.... Some trees just don't like being made into Guitars!

On the other hand... if you want something ridiculously easy to bend... Try quartersawn Oak... Get it wet and hot and you can bend it at crazy thicknesses... 1/8" is no problem what so ever.

Thanks

John

I had trouble bending a small piece of Padauk on a pipe (for a back plate on a headstock, with the bend to fit into a volute) and thought the guitar's sides would be a wretched job. They bent with no trouble at all on my fox-style bender using my usual approach with water-spritzing, wrap in foil, and maybe an extra 25 degrees of heat (and maybe an extra 2 or 3 minutes of heating) more than I would usually use for EIR and other regular suspects.

I've had no trouble with Bubinga at all, but I haven't bent any crazy figured stuff.

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Jim Kirby
kirby@udel.edu

Most bending problems are more from your process . Here is a video link to bending wood. http://www.youtube.com/results?search_q ... type=&aq=f
First off you need to use a thermometer and also have a controller so you don't over heat wood. Above is a prime example of charring from over heating. Mahogany and Maple like more heat and less water. Too much water can be worse than not enough . Most woods will bend in the 270 to 370 range. This doesn't mean to hold the heat that high for the 15 minutes you just need to attain that temp.
You want to look at your bending process , and you should be finished bending within 4 to 5 mins . Once you have the wood on the pattern you want to hold this at about 220 to 250 so yuo can set the bend. I normally use a 15 min cycle . Charring will occur with heat and duration. after about 3 to 4 minutes at 370 you can start to see charring on some woods while others can take this temp.
I like to monitor the heat blanket temp and use that to heat the steel to heat the wood. I don't care about the wood temp , I want to know the available heat for the wood. If you are using a hot pipe or bending iron , you need to develop a feel for the wood when it is ready to bend.
Hand bending can take about 40 minutes so don't rush and keep and eye and nose out . If you smell smoke, you are too hot or waiting too long.
Good luck

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Bloodwood is the hardest wood to bend I've had to work with.



Nanh. Bends easy, Here is a small youtube video of me bending a bubinga side.

http://www.youtube.com/watch?v=FO8-pvusHEE

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Brad -

What are you looking to build with? John, Todd and others who've already responded are the experts, and you've probably got what you need, but what's the guitar that you're building?

I think I'd focus on the wood that you want to build with, rather than starting with the hardest. If you're using a pipe, as I do, rather than a bending machine, I think you'll find lots of variability in the woods that you bend. (All the previous advice still holds, but you may have a narrower window of parameters dexpending on your project)

Regards,

I second the vote for bloodwood.

Mahogany can be really easy, and it can be really hard, and there's no way to know until you try.

Persimmon is sort of like what I've been told about working with a mule: it will do anything you ask so long as you ask nicely, but first you have to hit it up side the head with a 2x4 to get it's attention. With persimmon you need to get it wet, and get it hot and then LEAN on it. Osage is much the same.

I used to have problems bending the upper bouts on my form. I'd clamp the waist, and then do the lower bout. By this time the upper bout was a bit dry, so I'd give it a spritz, and it would crack all too often. I finally realized (I'm slow) that when I spritzed it I was cooling it down too much, and now I wet it after clamping the waist but before doing the lower bout. It's the little things...

That confirms the fact I don't have much experience!

When you talk of bloodwood, you bent it for sides or only for bindings strips?

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Francis Richer, Montréal
Les Guitares F&M Guitars

I agree with Al on this one set of mahogany bends like butter and the next set can seems like peanut brittle. I have found moisture or lack there of and the right temp and time in the bend is a good key. Mahogany seems to case harden pretty quickly so waisted time in the bend can lead to problems

I really have not found a wood that I would call difficult to bend. Meaning it is a problem once the you know the temp and moisture required. some woods bend better with a bit of steam some do better without any added moisture. The only real problem woods I have run into have all been high figure examples, quilted in perticular. They want to facet in the tight bends due to the grain direction changes. But even there SSII has solved the issue 99.9% of the time for me.

It is important on all woods but high figure in perticularly to have good support to the area being bent. Always use the spring loaded bottom bar in the waist area and keep the slats pulled tight to support the underside of the bend in places like cutaways and waists where the sandwich is not in constant contact with the bending mold as the bend progresses. paying attenion to this will help avid a lot of faciting due to figure grain orientation.

Has anyone with experience ever published a list of different species of wood, along with the best bending temperature for that wood and whether it does well with or without moisture? I would love to have a copy if it exists!
Wendy

Mahogany and sapele can really vary, and some are impossible to bend. I've seen sapele guitars go through 3 sets of sides. It gets worse with some figured wood.
For bloodwood and some other brittle and hard species I found that runout is the biggest enemy. Bloodwood and some ebonies without runout really bend easily, whereas a little bit of runout will make them snap on the grain lines at the first effort.

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Laurent Brondel
West Paris, Maine - USA
http://www.laurentbrondel.com/

I usually bend on a pipe, and I have had quite a bit of distress bending Jatoba. Neat wood, but it has its own mind ! I tried Supersoft, and that didn't fix it. I'll accept any suggestions!

John Mayes posted a very good bending data base several years ago. You can find it here on the 13th fret forum

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I'll go out on a limb here and challenge anyone to consistently bend high-flame curly maple to a 2" radius.
No faceting on the inside and no splintering/fracturing on the outside.
Just a nice smooth bend in .090" thickness.
Nelson

As mentioned earlier, some mahoganies can be a real bear. Think you got it all perfect & it straightens back out as soon as you take it out of the mold!
(By the way Truckjohn... That's a dred. Relax... It's not SUPPOSED to have a waist!)
Bloodwood is really brittle & the runout is a real side killer.
I recently bent some Mun Ebony & it wasn't easy. Very stiff on the handcrank, even though I thinned it down as far as I dared. I was worried about cracking an expensive set & added more water than I should have. Lots of cupping & I had to spend quite a while on the bending iron, refining the bends.
I bent a set of figured Claro walnut the next day & it was effortless, by comparison.
Zebrawood is pretty awkward too. It like to cup & is quite brittle. Sure is pretty, though!
Supersoft II has pretty much solved my issues with figured Bigleaf maple.
I haven't tried quilted maple yet, but I have a few gorgeous planks to resaw. I'm not expecting it to be trouble free...

[quote="Corky Long"]Brad -
I think I'd focus on the wood that you want to build with, rather than starting with the hardest. If you're using a pipe, as I do, rather than a bending machine, I think you'll find lots of variability in the woods that you bend. (All the previous advice still holds, but you may have a narrower window of parameters dexpending on your project)
quote]

Just a little background...I built a nice bender a year or two ago. It is a little different than the typical fox or doolin bender. It worked out very well but I am in the process modifing it to handle cutaways. (my first bender only bent non-cutaways). Anyways, I know the bender will be bend all the standard stuff because I have tested but I want to push things a little so that is what I am looking for the tougher stuff to bend to test the process.

Thanks!

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Brad
Avon, OH

It was scrap test pieces, similar to bindings or purflings. I tried bending on a pipe and I got nothing. I mean it, nothing. The pieces either remained strait or they would split, no matter how long I took or how hot the pipe was. But as Laurent mentioned, there was a lot of runouts in the pieces I tried to bend.

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

The stuff BobC was calling lacewood a few years back, which I have come to believe is not Roupala montaña (the usual hardwood yard lacewood), but really is the stiff now marketed as leopardwood--i.e., Panopsis rubellens.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Your limb broke...
3.2mm (that's about 1/8" folks) flamed maple bent under a 2" radius. Been doin' it for years.

Haans, very nice looking work!
I should have said 2" diameter (1" radius) as in a tight cutaway.
Those are very good looking bends especially in .125" thickness.
Thanks for posting the pix.
Care to share your bending methods?
Nelson

I'm sure I could bend 1" too, that front point is nearly 1"at the back side. But you said 2"...
No secrets here. You just have to find very soft red maple. Get it sopping wet and totally soaked for an hour under hot water, and using a strap, bend it on a very hot pipe. Burns some, but that sands out. You have to rock it back and forth and go slow. After you get it close, remove the strap (I use SS), and finish off on the pipe by heat drying the wood and keeping the tension on it. Do both sides.