A Question About Color

[Valerie Villars]

We have a wooden wind sculpture that looks remarkably like a DNA spiral. It is made of many slats of wood, painted different colors.

It is lacquered in what appears to be Krylon Spray paint. The colors are:

1) A new or lime green

2) orange

3) A light golden brown

4) yellow

6) Blue

7) purple

Then the colors repeat for one more sequence. There are about five slats in each sequence.

Why does only the green color have a moldy, dark dirt on it? I live in southern Louisiana and it is hot here with high humidity right now, in case that has something to do with why this is happening.

Why only the green and not any other color?

I hope someone is smart enough to answer this. It's a puzzle and we don't know the answer.

[Satori]

Here are some guesses. The slat painted green was contaminated before painted. Or, the green paint was not of the same quality as the other colors, or it may have been contaminated too. Green attracts light and moisture ... thus mold arises?

[Valerie Villars]

Satori, I guessed the green may have somehow attracted it due to biological programming. It attracts life. I was just trying to see if there was a mechanics behind it.

By they way, thank you for answering. Was that a guess or an educated answer? It's a sincere question.

[Satori]

VV. More of an educated guess, coupled with experience and a sprinkling of inductive logic. Of course, I could be entirely wrong. 🙂

[Hervé]

I would check what's the substance used as a pigment to produce the green color: Mineral? Organic? Fungus/mold food?

[turiya]

HOW TO PREVENT MOLD OR MILDEW ON PAINTED SURFACES

START WITH PAINT

A solid, mold and mildew prevention strategy starts with your paint. Certain types of paint are more resistant to mildew and mold than others. Mildew grows more quickly on exterior alkyd flat paint than it does on a gloss or semi-gloss enamel, because glossier paints are less porous; therefore, mold spores have difficulty adhering to them. Products containing linseed oil also attract mildew growth. Darker shades of color also dry quicker than lighter ones after it rains because they absorb heat instead of reflecting it. This makes darker shades less susceptible to mildew, so the best way to go would be properly priming the surface before applying paint and use a high-quality, light colored, latex paint.

http://noelpainting.com/how-to-preve...nted-surfaces/

[Valerie Villars]

Thanks Turiya. The only thing I couldn't understand is why the yellow, assuming the lighter colors absorb more heat, wouldn't have the same mold or mildew. All the paints are glossy.

Herve's explanation makes sense, too.

I forgot to mention it has white on the tips and there is no mold or mildew there either.