I had this happen on my first scratch build and the CA brand was/is Bob Smith - a very well respected CA brand.
This is one of the reasons that I HATE CA........
![[headinwall]](./images/smilies/headbangwalluf8.gif "Mad")
Sorry for yelling...... 
And sorry this happened to you J.
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| Yellowing under finish - glue? http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10101&t=17698 |
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| Author: | j.Brown [ Mon Jun 23, 2008 8:17 am ] |
| Post subject: | Yellowing under finish - glue? |
I have several spots of yellow discoloration on a guitar top under a finish. This was an experimental project, so I'm not too worked up about it, but I wanted to see if others had an idea of what it is. It appears to be in places that I would have used yellow glue or CA. The finish is a 2 part catalyzed polyurethane product. It was applied about 18 months ago and only started to yellow in the last 6 months. Very spotty. Looks very bad. What typically yellows under finish? Are some finishes better than others to prevent this? Is it direct contact with glue that causes it and will a sealer help prevent it? I've never had issues with KTM-9 or French polish. Thanks. -j. |
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| Author: | Kent Chasson [ Mon Jun 23, 2008 10:59 am ] |
| Post subject: | Re: Yellowing under finish - glue? |
I've seen CA do that over time where it wicks into the grain of top wood around a rosette or binding. Never seen anything else do it. I doubt the finish has anything to do with it or could prevent it. |
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| Author: | LuthierSupplier [ Mon Jun 23, 2008 11:00 am ] |
| Post subject: | Re: Yellowing under finish - glue? |
J., It is the CA you used. There are certain brands that do this more than others. But I don't know which brands are the culprit. I've seen some guitars that Edward did that did the same thing around the rosette and he was using Lacquer. So I don't think it is the finish, but rather the aging of the CA under the finish. Just my .02. |
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| Author: | j.Brown [ Mon Jun 23, 2008 11:07 am ] |
| Post subject: | Re: Yellowing under finish - glue? |
Well, I sure would like to know what CA brand does NOT do this...'cuz it is FUGLY. I wish I could remember what brand of CA I was using... I'm glad that its not a reaction to the finish, though. -j. |
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| Author: | Hesh [ Mon Jun 23, 2008 11:22 am ] |
| Post subject: | Re: Yellowing under finish - glue? |
I had this happen on my first scratch build and the CA brand was/is Bob Smith - a very well respected CA brand. This is one of the reasons that I HATE CA........ Sorry for yelling...... And sorry this happened to you J.
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| Author: | Tim McKnight [ Mon Jun 23, 2008 3:14 pm ] |
| Post subject: | Re: Yellowing under finish - glue? |
I have had it happen using LMI and StewMacs CA as well. |
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| Author: | j.Brown [ Mon Jun 23, 2008 3:55 pm ] |
| Post subject: | Re: Yellowing under finish - glue? |
UGH! Anyone have any experience with starbond yellowing....or more importantly, NOT yellowing? Thats exactly where it is, though...right around the rosette and the bindings where I used CA. I need to figure out how to avoid that happening. What do you tell a client when that happens? -j. |
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| Author: | Tim McKnight [ Mon Jun 23, 2008 7:13 pm ] |
| Post subject: | Re: Yellowing under finish - glue? |
How bout a free burst? |
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