Effect of UV radiation on white PVC

[MRMILSTAR]

About a week ago I was inspecting the base of my SGTC (6.5 KVA) and saw this brown spot on the bottom of the secondary coil form. This spot is about 4" x 4" and is in the direct line of site of my RSG electrode gaps. Its about 12" away from the spark gap. The UV radiation from the spark gap is so intense that it has turned this spot on the PVC tube brown. Total exposure time to UV was probably about one hour.

My fix was to use aluminum tape to cover that spot and protect it from further UV radiation damage. The pictures show before and after the patch.

The lesson learned is to remember that white PVC is very susceptible to UV radiation damage.

[Bradselph]

What would be the long term effects if left unprotected?

Would it just cause it to be brittle like a old pipe that was beat on by the weather?

[MRMILSTAR]

It becomes crumbly and brittle. I've heard that the brown areas can also become conductive.

[John123]

I've heard certain gases can cause yellowing too, got a disused bricked up fireplace with a plastic air vent covering it that's gone that colour even though it's behind a cabinet away from light.

[Bradselph]

i could see heat doing that as well not just gases