***** 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 Sun Dec 01, 2024 2:25 am


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 1 of 1
  [ 9 posts ] 
  Print view Previous topic | Next topic 
Author Message
Fasterthanlight
 Post subject: Humidity and Back Braces
PostPosted: Thu Apr 16, 2020 11:12 am 
Offline
Cocobolo
Cocobolo

Joined: Wed May 04, 2016 4:17 am
Posts: 150
First name: Gary
Last Name: Leddington
Focus: Build
Status: Amateur
So i was in my own world today gluing back braces on and when i realised i hadnt checked the humidity... it turned out to be 35% and i had already finished gluing.

How much of a problem is this? Should i be stripping of the braces and starting again when at 45%??

Thanks.

G.
Top
 Profile  
 
rbuddy
PostPosted: Thu Apr 16, 2020 11:24 am 
Offline
Cocobolo
Cocobolo
User avatar

Joined: Sun Jun 02, 2013 8:16 am
Posts: 486
First name: Brian
City: U.P.
State: Michigan
Focus: Build
I build the box in ~35% RH on purpose. I believe greater risk is in higher RH conditions as that would put the plates in shrink mode more often than compression on average. The shrinking causes cracks.

Brian R

_________________
Brian R, Wood Mechanic
N8ZED


These users thanked the author rbuddy for the post: Fasterthanlight (Sat Apr 18, 2020 3:03 pm)
Top
 Profile  
 
Clay S.
PostPosted: Thu Apr 16, 2020 11:51 am 
Offline
Brazilian Rosewood
Brazilian Rosewood

Joined: Sun Mar 30, 2008 8:20 am
Posts: 5968
For back braces it shouldn't be too much of a problem (it's only 10 points off what many people suggest bracing at). For soundboards it might be good to brace closer to 45 -50% R.H. as the swelling and shrinking affects the action on a lightly built "responsive" guitar.


These users thanked the author Clay S. for the post: Fasterthanlight (Sat Apr 18, 2020 3:04 pm)
Top
 Profile  
 
doncaparker
PostPosted: Thu Apr 16, 2020 12:00 pm 
Offline
Contributing Member
Contributing Member

Joined: Tue Dec 17, 2013 10:52 pm
Posts: 3076
First name: Don
Last Name: Parker
City: Charleston
State: West Virginia
Zip/Postal Code: 25314
Country: USA
Focus: Build
Status: Amateur
rbuddy wrote:
I believe greater risk is in higher RH conditions as that would put the plates in shrink mode more often than compression on average. The shrinking causes cracks.


Agreed. If you are going to vary from the 40-45% range while doing a glue-up of guitar parts, it is better to build too dry than too wet. Swelling tends to cause fewer serious problems than shrinking.


These users thanked the author doncaparker for the post: Fasterthanlight (Sat Apr 18, 2020 3:04 pm)
Top
 Profile  
 
Colin North
PostPosted: Thu Apr 16, 2020 12:09 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Fri Jul 10, 2009 4:44 am
Posts: 5498
First name: colin
Last Name: north
Country: Scotland.
Focus: Build
Status: Semi-pro
Fasterthanlight wrote:
So i was in my own world today gluing back braces on and when i realised i hadnt checked the humidity... it turned out to be 35% and i had already finished gluing.

How much of a problem is this? Should i be stripping of the braces and starting again when at 45%??

Thanks.

G.

No worries at, you're only 8 deg. low in my book - high/normal RH and then drying out, now that can be potato chip time....

_________________
The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.


These users thanked the author Colin North for the post: Fasterthanlight (Sat Apr 18, 2020 3:03 pm)
Top
 Profile  
 
TerrenceMitchell
PostPosted: Thu Apr 16, 2020 12:43 pm 
Offline
Cocobolo
Cocobolo

Joined: Thu Aug 15, 2019 12:00 pm
Posts: 255
Location: Tennessee
First name: Terry
Focus: Build
Status: Professional
Clay S. wrote:
For back braces it shouldn't be too much of a problem (it's only 10 points off what many people suggest bracing at). For soundboards it might be good to brace closer to 45 -50% R.H. as the swelling and shrinking affects the action on a lightly built "responsive" guitar.



Agreed. I live in Florida, and it's "never" dry... but I had a top that got braced on a day when the weather was unusually nice and I didn't realize the humidity was around 27%. Couple days later the thing wouldn't lay flat in the solera for nothing. Had to put it back in the go deck and heat up the braces until they "slid" a little. But, this is why we use hide glue! Guitar ended up sounding great with no problems.
Top
 Profile  
 
Fasterthanlight
PostPosted: Fri Apr 17, 2020 2:03 am 
Offline
Cocobolo
Cocobolo

Joined: Wed May 04, 2016 4:17 am
Posts: 150
First name: Gary
Last Name: Leddington
Focus: Build
Status: Amateur
Thanks guys... so what i'm hearing is, it shouldnt be a problem.. go ahead. Better a bit too dry that too wet?

G.

_________________
www.leddingtonguitars.com
Top
 Profile  
 
SteveSmith
PostPosted: Fri Apr 17, 2020 6:35 am 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Wed Oct 08, 2008 11:36 am
Posts: 7380
Location: Southeast US
City: Lenoir City
State: TN
Zip/Postal Code: 37772
Country: US
Focus: Repair
Yep

_________________
Steve Smith
"Music is what feelings sound like"


These users thanked the author SteveSmith for the post: Fasterthanlight (Sat Apr 18, 2020 3:03 pm)
Top
 Profile  
 
Joe Beaver
PostPosted: Sat Apr 18, 2020 12:44 pm 
Offline
Contributing Member
Contributing Member
User avatar

Joined: Thu Feb 09, 2006 2:35 pm
Posts: 2951
Location: United States
First name: Joe
Last Name: Beaver
City: Lake Forest
State: California
Focus: Build
I prefer to make and install my braces during low RH times. 30-35 percent sounds like a good time to me.

_________________
Joe Beaver
Maker of Sawdust


These users thanked the author Joe Beaver for the post: Fasterthanlight (Sat Apr 18, 2020 3:03 pm)
Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  Page 1 of 1
  [ 9 posts ] 

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 63 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