Official Luthiers Forum!

Deleted

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

Have not seen that. What is your repair approach going to be?

_________________
It's not what you don't know that hurts you, it's what you do know that's wrong.

I think the cedar oil doesn't allow the glue and finish to adhere to the wood strongly. Looks like the bridge built up stress and released it all at once, pushing up the finish like a little guitar earthquake. They weren't playing "Ring of Fire" when that happened were they?

Did the guitar sit in a hot car?

I've seen a lot of WRC topped guitars with Titebondish... bridge glues and can't say I've seen cold creep on WRC. I have seen it many times on spruce and every time there was also an episode of being left in a hot car or in a black case in the sun.

Great pics too, thanks for posting this so others can see what we mean cold creep is. It's not some guy at the mall in a trench coat with fake leggings tied below the knees....

What I usually see on WRC topped guitars are an over sensitivity to scoring fibers on the back edge and then the bridge rips the crap out of the top as it lifts.

You know too that in this neck of the woods it's commonly say How to you spell bridge reglue? Cordoba with a WRC top.

Any chance this guitar was in a hot climate recently? Also I can't know the brand and I'm not asking understanding that can be dicey but I see a bit more than cold creep in the pics. I see adhesion or possible finish adhesion issues. Normally Cat Poly is the hardest finish I know of to get off and it sticks like nobodies business. The bridge is definitely creeping but the finish looks delaminated too.

Woody, could we see a pic of the other edge of the bridge?
Thanks,
B

_________________
My memory is so good, sometimes I remember things that never happened.

WRC has low peel resistnace, and it may be that the finish layer is just peeling up along with some wood as the bridge moves. It may well have built up some stress, with the wood actually heling to hold it in place, before the strength of the wood was taxed too far, and it let go. THat could help explain the sudden release.

I would have thought that creep would occur going the other direction because of the pull of the strings on the bridge...

_________________
Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I'm interested in this too. I have a guitar with a similar problem and I've had it in the back of my mind for long time to attempt a repair.

In my case though, I think the problem wasn't cold creep. A respected local repair person looked looked it over and she concluded it was due to a combination of poor finish adhesion and bridge rotation under tension. There's no visible sign of the bridge having moved forward from creep. Also notice the finish lifting on the back edge of the bridge at the upper right, even though the bridge is not lifting at all.

Anyway, I'm wondering if this kind of damage can be repaired just at the site of the damage without having to refinish the whole top, and if so how you would go about it.

_________________
Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I'm wondering if a vinyl sealer was used before finish...very glad I never used WRC.
I used to have cold creep on center back and top joints on my personal mandolins when I used to use Titebond original way back. No, they were never heat abused.

cold creep is real and happens

_________________
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

I have some very real and recent experience with aliphatic glue creep on cedar with poly finish, and the Sisyphean task of repairing it. Like last week. Not fun and a losing proposition financially as an employer. HIDE GLUE, people!!!


Sent from my iPhone using Tapatalk Pro

_________________
Mountain Song Guitars www.mountainsongguitars.com

Deleted

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

It looks like it didn't move so much as we thought from the front edge pics but rather pushed and flaked off the poly finish. Gotta love those polyester finishes I wonder what glue he used for it.

One of the luthiers that is frequently in the shop recently brokered an exchange of three Cordoba student classicals with peeling bridges for new production instruments. This Purcellville-based repairman/builder works closely with several local instructional programs, and noticed the higher-than-normal incidence of bridge failures on two models of Cordoba instruments commonly used by academic programs in the area. Once approached, Cordoba suggested that they had experienced adhesive quality issues recently, and would honor their warranty.

Has Ann Arbor Guitars had any success in compelling warranty repairs on these instruments? Just curious!

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

Deleted

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

I've apparently "stepped in it" per the boss with regards to client confidentiality and need to discontinue participation in this thread. Please forgive me for deleting the three client-related posts, but it's that or find another position. Thanks for all the wonderful comments, gentlemen - much appreciated!

_________________
A constellation only takes shape when one maps the whole.
- Beth Brower

I hope you are not in too much hot water there Woodie and I hope your boss knows that this is a place where professionals often come too to discuss issues with their colleagues.