UV protection questions

[path1]

In Pac North West and have some white PVC fence posts that are about 12 years old. No UV problems or cracks from sun or fade. Pulled vent covers yesterday to inspect the roof and vent covers are brittle and weak and I put them on in 2008. The A/C cover is a Coleman and is 16 years old now and getting brittle but not cracked. For an experiment I painted them and spray'd the "new" clear Krylon uv protection on them. I'll see how they hold up, that is if they do. The product 303 some people say is equal to 40 SPF. I think we have some sun screen around the house that's 40 spf and it says only so many hours in direct sunlight.



Questions... What do people or manufactures put in some things that UV is not a problem and other part are. Both exposed to same conditions.

How does one add any real sun (UV) protection to exposed parts on RV's?

Thanks

[Almot]

I am not sure that 303 is equivalent to 40 SPF but I can tell you that it will wash away with rain soon. It is OK to use on rubber roof because you don't want to paint it often.

A/C cover is likely fiberglass, not PVC.

Fridge vent looks like PVC but it holds much better than my plumbing vents for some reason.

[tpi]

I have some patio furniture in my backyard which is at least 50 years old with original plastic webbing. Bright Orange County sun for the entire time. Other than a little chalking, it looks great. If they had the technology that long ago to make plastic hold up in the sun, they do now. Plastic used on some RV vent covers looks like it is intentionally degradable for quick breakdown.

[MEXICOWANDERER]

Adding carbon black to polyvinyl chloride plastics and nylon reduces UV degradation more than 90%. The problem? Look for it in the name of the additive. Model T color options...any color as long as it is black.

There is a particular plastic which is incredibly tough, and resembles that rough kind of bonded plywood. It is gray in color and is used in tool boxes and super premium battery boxes. It chalks in direct sunlight but if it weakens it is a slow process.

[Kayteg1]

PVC fence posts are thick, so they will chalk for long time before they start turning into dust.
16 years old for unprotected plastic is good time.
I am religious about keeping my toys protected from UV.
Neighbors keep $400 worth of **** in the garage, while 6 years old paint on $70,000 car is peeling off.
303 is good, but if you keep your RV exposed to sun all the time, I would consider painting AC cover and just keep on replacing the vents.

[westend]

Questions... What do people or manufactures put in some things that UV is not a problem and other part are. Both exposed to same conditions.

How does one add any real sun (UV) protection to exposed parts on RV's?

It is about the type of plastic and polymers used to fabricate it. Not all are equal.

With the good plastic paints available, painting any plastic parts that degrade quickly with UV would seem the best course of action.

FWIW, I painted one plastic vent cover with elastomeric roof paint to extend it's life. That is proving a good decision into year four.

[eric1514]

path1 wrote:
...
How does one add any real sun (UV) protection to exposed parts on RV's?

Thanks

With a cover.