Official Luthiers Forum!
http://mowrystrings.luthiersforum.com/forum/

Is really old wood just really hard to bend?
http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=53050		 Page 1 of 1
Author:  jfmckenna [ Mon Mar 30, 2020 8:07 am ]
Post subject:  Is really old wood just really hard to bend?
I'm having the worst time imaginable with this, total nightmare really. This is my 65th and 66th guitar not including some ukes, mando's and other instruments that required bending wood. And I've bent many different woods including some of the more difficult ones like Bubinga and figured Maple and so on. Never ever not once have I had problems till I came across this stash of BRW. Fortunately it's at no cost to me but that's another story.

I had this same issue with this BRW last year and reported it here: viewtopic.php?f=10101&t=51738&p=681274&hilit=brash+wood#p681274

Alan Carruth had suggested it could have been brash wood. This wood was cut in the 1950's so it's a good 60-70 years old now. But as most know BRW is supposed to bend like butter. This go around I started bending on my hot pipe like I always do and heard the fateful cracking of wood. I managed to adjust pressure and get the sides bent anyway. Not perfect at the waist becasue of the crack but certainly close enough.

Have you ever heard of the yips? Well I've got a severe case of it now. I felt like I could never bend wood again so I went and bought me a Blues Creek bending machine. Wonder full piece of equipment that thing is. So I bent a few sides of Walnut and Imbuia on the machine to practice at first. Then I got to the BRW and..........................CRACK!!!!!!!!!!!!!!!

WTH?

I've totally lost my nerve want to crawl in a corner and maybe take up something safe like knitting.

Here's the wood out of the machine.

Image

Image

I doubt there is anyway I could sand that to hide the crack but I'm open to suggestions.

So then I noticed something. All this wood, 3 sets now, that cracked has the very same grain too them. Could they have all been cut from the same board that was indeed brash wood?

So I grabbed another set that looks nothing like it and woefully put that in the bending machine. This set came out with so much spring back it was 2 inches away from the top points at the heel and head block. The waist was near perfect but most importantly NO CRACKS! So I put it in the bending machine again and it came out only slightly better. So then I bent it by hand, and noticed it was extremely difficult to bend. I bent it to where it was 1/2in inside the lines at the head and heel expecting spring back.

The next day it's 1/2 inch outside the lines again.

Image

Anyway I guess this is more of a rant but I'm open to any suggestions. I've never had such a tough time bending sides before. In fact I had always said it was the most fun thing to do when building guitars and now I have PTSD from doing it.

And I know the first thing that people think of when wood cracks is not enough heat but I definitely am using enough heat. I also used Super Soft 2 which seems to have no affect at all on rosewood.
Author:  Ken Lewis [ Mon Mar 30, 2020 8:31 am ]
Post subject:  Re: Is really old wood just really hard to bend?
What if your BRW had been kiln dried. While I have some thoughts on the matter I've no evidence to put forward.
Maybe someone else can offer some info??
Author:  phavriluk [ Mon Mar 30, 2020 8:50 am ]
Post subject:  Re: Is really old wood just really hard to bend?
Well, looks like the cracked wood got rejected by somebody sometime. I think there is little loss, i.e. the wood wasn't going to become guitar sides, but you just found out. Didn't pay anything, but didn't get anything either. I hope the set that did bend cost the same as the two that failed.
Author:  Ken Nagy [ Mon Mar 30, 2020 9:03 am ]
Post subject:  Re: Is really old wood just really hard to bend?
I've only bent wood by hand, mostly violins, but a small 1/2 scale guitar for the grandsons, and my arch top with a cutaway (on the pathetic violin iron I have). For the archtop ribs around the cutaway, 2 pretty tight turns, I planed and scraped them thinner, The rest of the rib was about 1.7 mm or so, like a cello. In the bends it is was more like 1,1-1.3mm more like a violin. I did the last violin ribs at 1.5, but they had a wicked flame, and I expected cracking at some point. I had to scrape and file them after.

A bent piece of wood is pretty strong even at 1mm. thick. Try the thicknessing trick.

You can always line with linen, or place vertical braces if you want. Coming from violins, guitars seem to be built like iron fortresses to me! I think the bends are far stiffer than the rest, so thinning doesn't hurt any. The linings give most of the stiffness, the ribs just keep the back and belly apart. Before linings, the ribcage is not nearly as stiff as after.

I have to have my iron on for at least an hour before it really starts working good. Maybe then, the wet wood, (I only put it under the faucet for a second, just before bending) doesn't bring the temperature of the iron down, and I get great steam. If it's going to bend, it will bend easy. If it isn't bending it needs to be hotter. That's what I like about the hand bending.

I don't bend spruce linings. They snap on me. Some of the masters used them. So what do I know? I use sycamore because I had some, it bent, it didn't snap. PTSD? No one needs that! Even me with the spruce linings. I'll get the iron really hot the next time and try spruce again. There is always leftovers so it makes sense.

Hope that helps.
Author:  Hesh [ Mon Mar 30, 2020 11:12 am ]
Post subject:  Re: Is really old wood just really hard to bend?
John I didn't read every post here but I wanted to know 1) your bending thickness and 2) if you have tried supersoft II?

FWIW it does look like BRW but OTOH the ink lines are not very profound making me wonder if this is a rasta imposta to BRW.

When I first got my bender from John Hall there was a learning curve for me with the stack, slats, brown paper, foil and what went where, etc. But none of this would account for the difficulty of being on a hot pipe. What a nightmare.
Author:  Tim L [ Mon Mar 30, 2020 11:16 am ]
Post subject:  Re: Is really old wood just really hard to bend?
I have a small (O size) set of perfectly 1/4'd BRW that is not only very dense but feels like it is case hardened. I know that's impossible but being heated for some reason is not and may have contributed to its' hardness. I'm afraid to bend it though both Ed Claxton and Jeff Traugott assure me that it will bend, I'll just need to soak it in water for a few days before trying. Not sure if super soft would work. Jeff has an article from years ago that describes how he soaks his wood before bending, in American Luthier??

First thing I would look for in wood that is cracking like that is runout.
Author:  Dave m2 [ Mon Mar 30, 2020 11:28 am ]
Post subject:  Re: Is really old wood just really hard to bend?
It's funny you should say that. I recently acquired some Indian Rosewood sets (not for zero money!) that were bought around 25 years ago.

I have never used rosewood before but I believed what everyone says that it should bend easily. but just look.

So I reduced thickness to around 1.7 mm, used more water, and didn't try to get it right into the 'horn' of the cutaway and this one worked.
Author:  jfmckenna [ Mon Mar 30, 2020 11:43 am ]
Post subject:  Re: Is really old wood just really hard to bend?
Hesh wrote:
John I didn't read every post here but I wanted to know 1) your bending thickness and 2) if you have tried supersoft II?

FWIW it does look like BRW but OTOH the ink lines are not very profound making me wonder if this is a rasta imposta to BRW.

When I first got my bender from John Hall there was a learning curve for me with the stack, slats, brown paper, foil and what went where, etc. But none of this would account for the difficulty of being on a hot pipe. What a nightmare.

Oh yes I forgot to mention that. Sides were thickness to .08 then I went to .075. And yes I did use SS2.

John had an excellent video posted on his YouTube channel which I used and like I said I did 4 sets to practice first and they came out beautiful, perfect in fact. No spring back and perfect shape.

It's definitely BRW. In short I've had an agreement with a gentleman to build him some guitars that he is reselling and it's his stash of BRW. Here is one from the same stash that is a bit more BRW-ish looking. But it has that distinctive smell too.

Image
Author:  jfmckenna [ Mon Mar 30, 2020 12:35 pm ]
Post subject:  Re: Is really old wood just really hard to bend?
Dave m2 wrote:
It's funny you should say that. I recently acquired some Indian Rosewood sets (not for zero money!) that were bought around 25 years ago.

I have never used rosewood before but I believed what everyone says that it should bend easily. but just look.

So I reduced thickness to around 1.7 mm, used more water, and didn't try to get it right into the 'horn' of the cutaway and this one worked.


Yup sometimes you just have to alter your pattern. I had to do that with the first set that cracked but was salvageable. As soon as I heard and saw the crack starting at the waist I used a block so that the edge of the block was just about 2mm to the right of the crack and pushed real hard to hold the crack shut while making the bend. It worked well enough but the waist is not as tight as the OM pattern should be but so it goes. The other side I made perfectly symmetrical so they would have the same 'error.' I guess in the end what I learned is that as great as side bendign machines are you have more control with a pipe.
Author:  Hesh [ Mon Mar 30, 2020 2:20 pm ]
Post subject:  Re: Is really old wood just really hard to bend?
jfmckenna wrote:
Hesh wrote:
John I didn't read every post here but I wanted to know 1) your bending thickness and 2) if you have tried supersoft II?

FWIW it does look like BRW but OTOH the ink lines are not very profound making me wonder if this is a rasta imposta to BRW.

When I first got my bender from John Hall there was a learning curve for me with the stack, slats, brown paper, foil and what went where, etc. But none of this would account for the difficulty of being on a hot pipe. What a nightmare.

Oh yes I forgot to mention that. Sides were thickness to .08 then I went to .075. And yes I did use SS2.

John had an excellent video posted on his YouTube channel which I used and like I said I did 4 sets to practice first and they came out beautiful, perfect in fact. No spring back and perfect shape.

It's definitely BRW. In short I've had an agreement with a gentleman to build him some guitars that he is reselling and it's his stash of BRW. Here is one from the same stash that is a bit more BRW-ish looking. But it has that distinctive smell too.

Image


Yep that's definitely BRW and very pretty too. I used to bend at .075 to .080ish too. I never used SSII but lots of folks here swear by it so you had that base covered too. Sounds like you have some uppty wood there idunno
Author:  Herr Dalbergia [ Thu Apr 02, 2020 3:42 am ]
Post subject:  Re: Is really old wood just really hard to bend?
Looks to me like not hot enough and too fast too much pressure. I would try to bend this wood by hand on a really hot bending pipe. Quite sure it would work. No water or softner, just heat, lots of.....
Author:  CraigSz [ Thu Apr 02, 2020 7:03 am ]
Post subject:  Re: Is really old wood just really hard to bend?
Sorry to hear about the bending issues particularly considering it is Brazilian Rosewood. While I have no experience with Brazilian I have found that really old wood ( 50 years and older) definitely behaves differently when heat bending.
The solution for me as was mentioned by someone else was to soak the sides in hot water for around 30 mins rather than just misting with a spray bottle . I use a homemade fox style bender. I also folded aluminum foil over the side leaving just one edge for the steam to escape whilst bending. I use 2 spring steel slats and have the blanket on top and 3 x 150watt globes below. Once bending is complete I reduce the blanket temp to 240degrees f and leave for another 40 mins to completely dry the wood and set the bend. Hope this helps . All the best .

Sent from my SM-A520F using Tapatalk
Author:  Ken Jones [ Fri Apr 03, 2020 2:44 am ]
Post subject:  Re: Is really old wood just really hard to bend?
That looks like runout to me.


Sent from my iPhone using Tapatalk Pro
Page 1 of 1 All times are UTC - 5 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/