Union O Ring Lubricant?

[tinpusher]

On the underwater housing for my digital camera there is a O ring and the instructions call for applying a light coating of silicon gel (feels like vaseline) to the the O ring before sealing shut. Does anyone use anything on the O rings in PVC unions?

[Nemo]

For your PVC Union spit works great. Or nothing at all will be fine.

[seashells]

we use gel or paste silicon lube. reduces chemical breakdown of o rings.

doug