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| Cold Creeping Bridge and Polyester Finish Release http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10101&t=50245 |
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| Author: | Woodie G [ Sun Jan 28, 2018 10:53 am ] |
| Post subject: | Cold Creeping Bridge and Polyester Finish Release |
Deleted |
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| Author: | Terence Kennedy [ Sun Jan 28, 2018 11:47 am ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
Have not seen that. What is your repair approach going to be? |
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| Author: | Clay S. [ Sun Jan 28, 2018 12:11 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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? 
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| Author: | Barry Daniels [ Sun Jan 28, 2018 12:17 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
Did the guitar sit in a hot car? |
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| Author: | Hesh [ Sun Jan 28, 2018 2:13 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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. |
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| Author: | Bri [ Sun Jan 28, 2018 2:23 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
Woody, could we see a pic of the other edge of the bridge? Thanks, B |
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| Author: | Alan Carruth [ Sun Jan 28, 2018 2:45 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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. |
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| Author: | sdsollod [ Sun Jan 28, 2018 2:57 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
I would have thought that creep would occur going the other direction because of the pull of the strings on the bridge... |
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| Author: | J De Rocher [ Sun Jan 28, 2018 4:21 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
Terence Kennedy wrote: Have not seen that. What is your repair approach going to be? 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. Attachment: Finish defect.jpg
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| Author: | Haans [ Sun Jan 28, 2018 4:56 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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. |
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| Author: | bluescreek [ Sun Jan 28, 2018 8:20 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
cold creep is real and happens |
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| Author: | Ken Jones [ Sun Jan 28, 2018 9:28 pm ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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 |
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| Author: | Woodie G [ Mon Jan 29, 2018 8:16 am ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
Deleted |
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| Author: | jfmckenna [ Mon Jan 29, 2018 8:27 am ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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.
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| Author: | Woodie G [ Mon Jan 29, 2018 8:46 am ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
Hesh wrote: 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. 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! |
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| Author: | Woodie G [ Mon Jan 29, 2018 8:50 am ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
Deleted |
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| Author: | Woodie G [ Mon Jan 29, 2018 8:59 am ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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! |
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| Author: | jfmckenna [ Mon Jan 29, 2018 10:44 am ] |
| Post subject: | Re: Cold Creeping Bridge and Polyester Finish Release |
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. |
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