Back and sides are twisted

Costs are rising and times are tough.
Please consider a donation to keep this
place going.

Welcome to one of the most active flamenco sites on the Internet. Guests can read most posts but if you want to participate click here to register.

This site is dedicated to the memory of Paco de Lucía, Ron Mitchell, Guy Williams, Linda Elvira, Philip John Lee, Craig Eros, Ben Woods, David Serva and Tom Blackshear who went ahead of us.

We receive 12,200 visitors a month from 200 countries and 1.7 million page impressions a year. To advertise on this site please contact us.

You are logged in as Guest

Users viewing this topic: none

Printable Version

All Forums >>Discussions >>Lutherie >>

Page: [1]

Message

<< Newer Topic Older Topic >>

Ahmed Flamenco

Posts: 163
Joined: Feb. 22 2014
From: Egypt

Back and sides are twisted

Hello everyone I'm in a trouble a back and sides for a new coming guitar are twisted.
Is there anything I can do?

Images are resized automatically to a maximum width of 800px

Attachment (2)

REPORT THIS POST AS INAPPROPRIATE | Date Apr. 18 2017 19:26:02

estebanana

Posts: 9351
Joined: Oct. 16 2009

RE: Back and sides are twisted (in reply to Ahmed Flamenco)

Too much moisture bending the ribs. The waves don't look too bad however. If ribs are thick enough you can sand that out with a hard flat sanding block right before you cut the binding channel.

If the ribs are already really thin and unassembled- You can create a laminating jig shaped like a rib and glue thin maple veneer to the inside of the rib to give it more thickness then carefully sand out the waves.

Or leave the waves. In cello making some makers would simply go with that because it's part of the game and it look natural. Guitar making has it's priorities in the wrong place on stuff like that.

Another option is to glue cloth tape to the inside of the rib for extra strength. A common practice in steel string construction.

Buyers will question it, so I recommend fixing it. But in the bigger picture guitar making suffers from boring flat planes, but only a minority of viewers think that is true.

If you need help with any of those solutions let us know.
-----------------------------------------------------------------

You have to plane the braces off the back, clean the glue residue, make new braces and reglue them.

Make sure the braces are strong wood. Arch them carefully. and most important check your glue up area to make sure the room is dry. Under 50% relative humidity.

_____________________________

https://www.stephenfaulkguitars.com

REPORT THIS POST AS INAPPROPRIATE | Date Apr. 19 2017 3:39:34

Anders Eliasson

Posts: 5780
Joined: Oct. 18 2006

RE: Back and sides are twisted (in reply to Ahmed Flamenco)

The back has most probably bent because you have glued the braces in humid conditions and now its a lot dryer.
Controlling humidity is extremely important when building wooden instruments.

I agree with Stephen on his views on the sides. I call it bubble up. In violin building it happens a lot because the sides are only 1mm thick and you have to use a certain amount of moist to bend the highly figured maple. So the "window" is very narrow. You can easily bend to dry and scorch and not get the right shape or bend to wet and get bubble up or even see the highly figured cook into pieces (fall apart)
Cypress like yours need very little moist. The problem with bending cypress is that if they get to hot, they lock and wont bend at all and then you have to wait a while and continue the bending

_____________________________

Blog: http://news-from-the-workshop.blogspot.com/

REPORT THIS POST AS INAPPROPRIATE | Date Apr. 19 2017 14:43:40