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Author Topic: Why does my pink paint turn white?  (Read 8250 times)

Offline GlentoranMark

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Why does my pink paint turn white?
« on: 01/04/2011 09:25:02 »
Hello all, the wife got me decorating  [:-'(] but we bought this paint that goes on pink but ends up white.

Great to see all the spots we missed but how does it work?


 

Offline imatfaal

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Why does my pink paint turn white?
« Reply #1 on: 01/04/2011 14:22:53 »
Is that deliberate / advertised feature?  Sounds really useful for getting a decent coat of paint on the same colour surface.
 

Offline Evie

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Why does my pink paint turn white?
« Reply #2 on: 01/04/2011 15:24:48 »
I found an article online that talks about the very paint you must have used. Yes, it is intentionally made so that you can re-paint your white walls or ceiling and see where you've been and where you've missed.

In the article, the author contacted the manufacturer. They revealed that the pink is a temporary dye, but wouldn't explain further (don't want to let their secret out!).

Anyone have any good guesses on the mechanism that allows the pink dye to be "temporary?"
 

Offline imatfaal

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Why does my pink paint turn white?
« Reply #3 on: 01/04/2011 15:53:41 »
I suppose you could have a dye that reacts with oxygen/water/co2 in the air to denature and lose its colour
 

Offline Geezer

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Why does my pink paint turn white?
« Reply #4 on: 01/04/2011 20:06:53 »
http://www.freepatentsonline.com/EP1400574.html

Quote: "Phenolphthalein solution at pH 9.5 is a red colour but if the solution is dried only white crystals remain"

I'm surprised Bored Chemist didn't come up with this one. He could have made a bundle!  :D
« Last Edit: 01/04/2011 22:24:40 by Geezer »
 

Offline chris

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Why does my pink paint turn white?
« Reply #5 on: 01/04/2011 22:40:09 »
What a fantastic invention; I would never have thought of doing something like this phenolphthalein trick; ingenious.

Chris
 

Offline Geezer

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Why does my pink paint turn white?
« Reply #6 on: 02/04/2011 06:45:07 »
The patent describes a lot of different ways that might produce a similar result. But do not be too discouraged if your reaction is, "Doh! Why didn't I think of that?"

Based on my rather limited experience, the best inventions are those that provide a solution to a particular problem. So, the first step is to identify a problem.
 

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Why does my pink paint turn white?
« Reply #6 on: 02/04/2011 06:45:07 »

 

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