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White in marble yellowing
Posted by:
Aaron Cavanaugh
(---.hsd1.mn.comcast.net)
Date: October 03, 2005 12:34PM
Noticed on two of my rods that the white in the marbled areas is yellowing. Did I do something incorrectly? What causes this? Probably nothing I can do short of stripping it all and redoing, right? Re: White in marble yellowing
Posted by:
Robert crabtree
(---.proxy.aol.com)
Date: October 03, 2005 12:41PM
my ??? what kind of finish did you use how long has the rod been in use.... just wondering Re: White in marble yellowing
Posted by:
Andy Dear
(---.stic.net)
Date: October 03, 2005 01:07PM
All epoxy finishes yellow to some degree....even in the dark. This whole marketing ploy of "Non-Yellowing" is a bunch of mis-information. I did a test just 2 weeks ago. I have a white trolling blank that put four of the major brands of finishes on. After 3 days in the sun, they looked horrible...yellow, borderline brown. Don't fret guys....I am in the process of developing something for you soon to try that will solve this problem, or at least delay it for a very long time.
Andy Dear Lamar Manf. Re: White in marble yellowing
Posted by:
Edward D. Smith
(---.ard.bellsouth.net)
Date: October 03, 2005 01:58PM
Andy,
I agree 110%. I have tried several finishes on American Holly and cedar with white grain. They all yellow to some extent. You might find some oils that don't yellow. I know Birchwood-Cassey yellows. The gloss finish is the important thing in this matter. Being the chemist that I am, I don't think anything with a carbon double bond to any element will be yellow free. Permagloss with its cyanoacrylates and its alkyl acrylates come close, but they are not totaly yellow free. I would be very interested in your new development. I know there are some chemist among the rod building community-a UV/VIS scan would be very helpful and interesting in an evaluations of this type. I could probably get scan done. (I am retired so I would have to get a friend to do this for me). Very interested in your development. Hope to see it in Charlotte in 2006. Ed Smith Re: White in marble yellowing
Posted by:
Anonymous User
(Moderator)
Date: October 03, 2005 02:00PM
This is interesting for me, primarily because a year or so ago I colored some epoxy white and used it as the base coat for some marbling. The epoxy was
Flex Coat which is known for its tendency to yellow. But, that white is just as white now as the day I applied it. I had decided that the white pigment made the epoxy opaque and therefore stopped the yellowing of the hardener. I can't say for sure, but I do know the white marbling I've done has stayed very bright white. No yellowing that I can tell, so far. Sunlight degrades about everything. Whatever you have that is yellowing can't be put right. You either have to live with it or redo it. That's about all I can offer. ...................... Re: White in marble yellowing
Posted by:
Edward D. Smith
(---.ard.bellsouth.net)
Date: October 03, 2005 09:04PM
Tom,
What I was refering to applies to unpigmented resins. Once pigments areincorporated , the rules change. You limit the pathlenght of the light thru the resin thus yellowing is not as noticable. You are right, pigmented resins do not noticibly yellow. I was refering more to clear finish on wood. It is minimaily noticable on colored rods. The fact that Permagloss is so thin is why yellowing is negligible. This is based on Beer's law-and no it does not apply to suds unless you compare a glass 55 gal drum to a 12 oz. bottle of very different light pathlenght. Then it is detectible to the naked eye. I don't really want to explain Beer's law to those not trained in science. I just hope this does not open a big can of worms. Otherwise I'm gone fishing with the can of worms. The bottomline in all this is that thickness and transparentcy are important as to the amount of yellow that is noticable. Ed Re: White in marble yellowing
Posted by:
Anonymous User
(Moderator)
Date: October 03, 2005 11:12PM
Yes, that's what I thought - it was the only thing that made sense to me.. And the statement about thickeness and noticeable yellowing of the clear finishes have been discussed here many times previously.
I do have some fairly high build finishes made from multiple coats of Permagloss and they still appear nearly water white clear after many years. .................. Re: White in marble yellowing
Posted by:
Mike Barkley
(---.nap.wideopenwest.com)
Date: October 05, 2005 07:00PM
I have used epoxy finish colored with white TAP pigment in marbleing and as "underwraps" with exposed areas under a diamond wrap. Some are several years old and show no sign of yellowing.
Mike Sorry, only registered users may post in this forum.
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