***** Guitar Project Jigs, Tools & Techniques Online Resources Archives OLF Video Page Library of plans MP3 Library Inlay Class
Offical Luthiers Forum





And our community proudly sponsored by:

RC Tonewoods | Stewart MacDonald | LuthiersForum
TasmanianTonewoods | OLF | OLF MERCH
Luthier Suppliers | Pacific Coast Woods | ELEVATE
OLF X | Tasmanian Acoustic Tonewood | Luthiers Forum Store!
Luthiers Forum | OLF Facebook | AVAIL SPACE
OLF | Alaska Specialty Woods | A.Hix Tonewood
Duke of Pearl | Birkonium CNC | Space




Official Luthiers Forum!

Owned and operated by Lance Kragenbrink
It is currently Wed Aug 06, 2025 5:37 pm


Board index » Luthiers Forum Rooms » Guitar Building Forum

All times are UTC - 5 hours


Forum rules


Be nice, no cussin and enjoy!




Post new topic Reply to topic  Page 4 of 5
  [ 109 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next
  Print view Previous topic | Next topic 
Author Message
DanSavage
PostPosted: Tue Mar 03, 2015 9:37 pm 
Offline
Cocobolo
Cocobolo

Joined: Tue May 01, 2012 12:54 pm
Posts: 147
Location: Trabuco Canyon, CA
First name: Dan
Last Name: Savage
City: Trabuco Canyon
State: CA
Zip/Postal Code: 92679
Country: USA
Kewl. I think it's an interesting subject, too.

As I said earlier, I've really wanted to try torrefied wood so I could decide for myself whether there's any there, there.

I recently restored a 1976 guitar. I wanted to use torrefied wood for the top, but couldn't find it anywhere. I tried contacting Bourgeois guitars, but never heard back. I tried contacting other wood suppliers who torrefy wood, but no one wanted to talk to me. Finally, I just re-topped the guitar with Bearclaw Stika spruce using a brace pattern not usually used on this particular brand and ended up with a really nice sounding guitar.

I acquired another guitar of the same brand which is a 1978 vintage. I was thrilled to see that John Hall of Blues Creek Guitars was selling torrefied top wood and I bought it as soon as I saw it. My plan is to rebuild this one using the same brace pattern and to compare the sound of the two guitars.

Granted, one will have Stika spruce and the other will have Red Spruce, so there's that difference. Ideally, a true comparison would use the same species of wood. At the very minimum, I will have achieved the goal of a torrefied top guitar. :)
Top
 Profile  
 
Tai Fu
PostPosted: Tue Mar 03, 2015 9:55 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Sep 24, 2008 8:55 pm
Posts: 3820
Location: Taiwan
First name: Tai
Last Name: Fu
City: Taipei
Country: Taiwan
Focus: Repair
Status: Semi-pro
He's dead, Jim.

KAHN!!!!!!!!

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com


These users thanked the author Tai Fu for the post: Pmaj7 (Tue Mar 03, 2015 11:24 pm)
Top
 Profile  
 
Mike Franks
PostPosted: Thu Mar 05, 2015 1:36 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Nov 03, 2005 1:49 am
Posts: 235
Location: United States
To the best of my knowledge, there is no supplier currently offering true torrefied soundboards for sale to the small luthier community. There are a few sources for baked tops but there is a world of difference between baking and torrefication. Torrefication involves heating the soundboard in a vacuum or rarified atmospheric chamber to a temperature which exceeds the flash point of the wood. Only the absence of oxygen prevents the top from burning or scorching.

If anyone knows of a source for actual torrefied tops, I would love to know.

Mike Franks www.mjfranksguitars.com
www.facebook.com/mjfranksguitars
Top
 Profile  
 
Tai Fu
PostPosted: Thu Mar 05, 2015 2:02 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Sep 24, 2008 8:55 pm
Posts: 3820
Location: Taiwan
First name: Tai
Last Name: Fu
City: Taipei
Country: Taiwan
Focus: Repair
Status: Semi-pro
that sounds like making charcoal to me

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com
Top
 Profile  
 
mcgr40
PostPosted: Thu Mar 05, 2015 2:37 pm 
Offline
Cocobolo
Cocobolo

Joined: Sat Jul 11, 2009 10:06 am
Posts: 179
First name: mike
Last Name: mcgrail
State: ky
Country: usa
Focus: Build
Status: Amateur
Mike,
The bluescreekguitars website has a red spruce top for sale listed as "torrified"- but I don't know if his definition is the same as you are interested in.

Mike
Top
 Profile  
 
kencierp
PostPosted: Thu Mar 05, 2015 5:00 pm 
Offline
Koa
Koa

Joined: Sat May 19, 2007 11:03 am
Posts: 1737
Location: Litchfield MI
Focus: Build
Status: Professional
Enjoy

http://bourgeoisguitars.net/wp-content/ ... action.pdf

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/
Top
 Profile  
 
Hesh
PostPosted: Fri Mar 06, 2015 7:52 am 
Offline
Old Growth Brazilian Rosewood
Old Growth Brazilian Rosewood
User avatar

Joined: Fri Nov 02, 2007 9:49 am
Posts: 13651
Location: Ann Arbor, Michigan
First name: Hesh
Last Name: Breakstone
City: Ann Arbor
State: Michigan
Country: United States
Status: Professional
Looks like it's student body torrified these days.

Who's selling the stuff?
Top
 Profile  
 
kencierp
PostPosted: Fri Mar 06, 2015 9:42 am 
Offline
Koa
Koa

Joined: Sat May 19, 2007 11:03 am
Posts: 1737
Location: Litchfield MI
Focus: Build
Status: Professional
One of the makers I know that is doing his own tests indicated that the guys booking the large autoclaves for tonewoods are still very inconsistent providing product. Another interesting point (at least I thought) was that the Martin process (rumor has it) only heats the wood to just under 300 degrees where as the process for architectural timbers gets the temps up to about 400 degrees. So that does bring up the question -- how are the pieces of torrified tone wood out there really being processed -- what is it?

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/
Top
 Profile  
 
DanSavage
PostPosted: Fri Mar 06, 2015 12:51 pm 
Offline
Cocobolo
Cocobolo

Joined: Tue May 01, 2012 12:54 pm
Posts: 147
Location: Trabuco Canyon, CA
First name: Dan
Last Name: Savage
City: Trabuco Canyon
State: CA
Zip/Postal Code: 92679
Country: USA
mcgr40 wrote:
Mike,
The bluescreekguitars website has a red spruce top for sale listed as "torrified"- but I don't know if his definition is the same as you are interested in.

Mike


That's where I got mine.

I can't imagine John would be selling baked wood and then call it 'torrefied'.
Top
 Profile  
 
DanSavage
PostPosted: Fri Mar 06, 2015 12:53 pm 
Offline
Cocobolo
Cocobolo

Joined: Tue May 01, 2012 12:54 pm
Posts: 147
Location: Trabuco Canyon, CA
First name: Dan
Last Name: Savage
City: Trabuco Canyon
State: CA
Zip/Postal Code: 92679
Country: USA
kencierp wrote:
Enjoy

http://bourgeoisguitars.net/wp-content/ ... action.pdf


Good article. It reinforces everything I've read/heard about torrefied tone wood.
Top
 Profile  
 
Tai Fu
PostPosted: Fri Mar 06, 2015 12:54 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Sep 24, 2008 8:55 pm
Posts: 3820
Location: Taiwan
First name: Tai
Last Name: Fu
City: Taipei
Country: Taiwan
Focus: Repair
Status: Semi-pro
Also how do you torrefy woods without it warping and turning into potato chips? Kiln drying wood is already a bit of art.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com
Top
 Profile  
 
DanSavage
PostPosted: Fri Mar 06, 2015 12:58 pm 
Offline
Cocobolo
Cocobolo

Joined: Tue May 01, 2012 12:54 pm
Posts: 147
Location: Trabuco Canyon, CA
First name: Dan
Last Name: Savage
City: Trabuco Canyon
State: CA
Zip/Postal Code: 92679
Country: USA
kencierp wrote:
So that does bring up the question -- how are the pieces of torrified tone wood out there really being processed -- what is it?


According to Yamaha's patent, the time/temp/pressures used are dictated by the species and dimensions of the wood.

The temps they use range from 120 to 200° C. (248 to 392° F)
Top
 Profile  
 
DanSavage
PostPosted: Fri Mar 06, 2015 1:11 pm 
Offline
Cocobolo
Cocobolo

Joined: Tue May 01, 2012 12:54 pm
Posts: 147
Location: Trabuco Canyon, CA
First name: Dan
Last Name: Savage
City: Trabuco Canyon
State: CA
Zip/Postal Code: 92679
Country: USA
Tai Fu wrote:
Also how do you torrefy woods without it warping and turning into potato chips? Kiln drying wood is already a bit of art.


I believe the wood is kiln dried first, then put into the autoclave for torrefaction.

According to the Yamaha patent, the torrefaction process relieves residual strains which cause warps. It says there are methods for torrefying raw wood and a different method for torrefying already-shaped wood.

US 6667429 B2 wrote:
The high pressure steam contains a large amount of active species such as hydrogen ions, hydroxide ions, hydrogen radicals, and hydroxide radicals, and hydrolyzes cellulose, hemicellulose, and lignin which are main components of wood. When wood is put under the above conditions, the above active species are impregnated into the wood with the steam, and subsequently, hydrolyze hemicellulose, partially repolymerize lignin, decompose amorphous portions of cellulose and rearrage the decomposed portion. Accordingly, residual strain in the wood is resolved, and the degree of crystallinity and the width of micells increases. As a result, the dynamic modulus of elasticity (E) increases and the loss angle (tan δ) decreases. Furthermore, since a part of the decomposed component and extracted component of the wood is removed with water, density (ρ) decreases.

...

The wood retaining with the high pressure steam is treated by slowly decreasing the pressure and the temperature to room pressure and temperature so that the wood does not break due to pressure differences between inside and outside of the wood, and subsequently, the wood is treated by a drying step. The drying step is carried out by a known method for drying wood such as air-drying, heating-drying, and heating and decompression-drying, or a combination thereof. Furthermore, the desired moisture content is determined in response to the purpose of the modified wood being obtained, in particular, the moisture content is preferably set at 5 to 15% by weight.


These users thanked the author DanSavage for the post: Gasawdust (Mon Mar 09, 2015 7:22 am)
Top
 Profile  
 
kencierp
PostPosted: Fri Mar 06, 2015 2:12 pm 
Offline
Koa
Koa

Joined: Sat May 19, 2007 11:03 am
Posts: 1737
Location: Litchfield MI
Focus: Build
Status: Professional
‘Torrefaction can’t make
a bad piece of wood
sound good.’
—DANA BOURGEOIS

_________________
Ken Cierp

http://www.kennethmichaelguitars.com/
Top
 Profile  
 
Tai Fu
PostPosted: Fri Mar 06, 2015 2:15 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood
User avatar

Joined: Wed Sep 24, 2008 8:55 pm
Posts: 3820
Location: Taiwan
First name: Tai
Last Name: Fu
City: Taipei
Country: Taiwan
Focus: Repair
Status: Semi-pro
Torrefaction is no substitute for overbuilding guitars either.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com
Top
 Profile  
 
DanSavage
PostPosted: Fri Mar 06, 2015 3:46 pm 
Offline
Cocobolo
Cocobolo

Joined: Tue May 01, 2012 12:54 pm
Posts: 147
Location: Trabuco Canyon, CA
First name: Dan
Last Name: Savage
City: Trabuco Canyon
State: CA
Zip/Postal Code: 92679
Country: USA
kencierp wrote:
‘Torrefaction can’t make
a bad piece of wood
sound good.’
—DANA BOURGEOIS


From what I gather, the converse is true:

Torrefaction can make a good piece of wood sound better.
Top
 Profile  
 
jeb98
PostPosted: Fri Mar 06, 2015 5:57 pm 
Offline
Contributing Member
Contributing Member

Joined: Mon Nov 30, 2009 10:22 pm
Posts: 123
First name: Jonas
Last Name: Baker
City: North Haven
State: CT
Zip/Postal Code: 06473
Country: United States
Focus: Build
Status: Amateur
If I have access to an autoclave, is there a recommended way to process wood into torrefied wood? I guess we're all wondering the same thing but I'd be willing to try it out.

Best,

Jonas
Top
 Profile  
 
George L
PostPosted: Fri Mar 06, 2015 7:11 pm 
Offline
Contributing Member
Contributing Member

Joined: Fri May 09, 2008 2:25 pm
Posts: 1958
First name: George
City: Seattle
State: WA
Country: USA
Focus: Build
Status: Amateur
There you have it. If torrefaction can't make a bad piece of wood sound good, then it can't make a good piece of wood sound great, and it can't make a great piece of wood sound greater. End of story. Turn off the ovens, fire the ad agency and get back to work. bliss

_________________
George :-)
Top
 Profile  
 
J De Rocher
PostPosted: Fri Mar 06, 2015 7:34 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Mon Apr 16, 2012 12:47 pm
Posts: 2575
First name: Jay
Last Name: De Rocher
City: Bothell
State: Washington
I think you hit the nail squarely on the head there. If the quote about a bad piece of wood is true, then the rest of your statement just stands to reason.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter
Top
 Profile  
 
meddlingfool
PostPosted: Fri Mar 06, 2015 7:45 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Wed Feb 20, 2008 7:15 pm
Posts: 7548
First name: Ed
Last Name: Bond
City: Nanaimo
Country: Canada
Focus: Build
Status: Professional
:D Don't knock it til you try it!
Top
 Profile  
 
Alex Kleon
PostPosted: Fri Mar 06, 2015 8:00 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Tue Mar 01, 2011 1:32 pm
Posts: 3470
First name: Alex
Last Name: Kleon
City: Whitby
State: Ontario
Zip/Postal Code: L1N8X2
Country: Canada
Focus: Build
Status: Amateur
Maybe I can cook some uke tops in the autoclave at the Vet clinic my wife works at. I'm sure her boss wouldn't mind! :)

Alex

_________________
"Indecision is the key to flexibility" .... Bumper sticker
Top
 Profile  
 
mike-p
PostPosted: Sat Mar 07, 2015 3:30 am 
Offline
Cocobolo
Cocobolo

Joined: Wed Jan 22, 2014 4:59 pm
Posts: 375
Location: Co cork Ireland
Country: Ireland
Focus: Build
No expert here but I played a bourgeois aged tone dread. It was an interesting guitar. It didn't sound like an old Martin but didn't sound like a new one either. It had a mellow and dry tone, certainly reminiscent of an old guitar but certainly not the same. Either way it was a great sounding guitar and usually a brand new dread is probably my last favourite guitar sound.
Top
 Profile  
 
George L
PostPosted: Sat Mar 07, 2015 3:42 pm 
Offline
Contributing Member
Contributing Member

Joined: Fri May 09, 2008 2:25 pm
Posts: 1958
First name: George
City: Seattle
State: WA
Country: USA
Focus: Build
Status: Amateur
meddlingfool wrote:
:D Don't knock it til you try it!

For the record, I'm not knocking torrefaction and have no doubt that the process can alter a piece of wood enough to potentially change a guitar's tone. Whether or not the instrument then sounds "better" is a subjective matter. As always, there's the rub.

_________________
George :-)
Top
 Profile  
 
meddlingfool
PostPosted: Sat Mar 07, 2015 5:11 pm 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Wed Feb 20, 2008 7:15 pm
Posts: 7548
First name: Ed
Last Name: Bond
City: Nanaimo
Country: Canada
Focus: Build
Status: Professional
Indeed! I'll settle for different and identifiable, like the difference between rosewood and mahogany.
Top
 Profile  
 
KThomas
PostPosted: Sun Mar 08, 2015 8:35 pm 
Offline
Cocobolo
Cocobolo

Joined: Fri Nov 16, 2007 8:36 am
Posts: 114
Location: United States
First name: kurt
Last Name: thomas
City: colden
State: ny
Zip/Postal Code: 14033
Status: Amateur
Since the torrefication process seemed to be too complicated to duplicate in my small shop, I got around it by building a time machine. This has allowed me to go 40-50 years into the future, and bring back naturally aged tops which we are very happy with. You have heard of NOS (New Old Stock) well this is ONS (Old New Stock). If anyone is interested, I am offering a discount to OLF members of 15%, the problem is we need to list these tops in 2065 dollar equivalents.

_________________
_____________________________

Kurt Thomas

"There's a first time for everything even if you do it by mistake."
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 4 of 5
  [ 109 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next

Board index » Luthiers Forum Rooms » Guitar Building Forum

All times are UTC - 5 hours


Who is online

Users browsing this forum: No registered users and 44 guests

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
Powered by phpBB® Forum Software © phpBB Group
phpBB customization services by 2by2host.com