Ok to spray paint on cables?

[robinbanks]

No - it's plasticised.

And what do you think will happen?

 

[JohnW2]

And what do you think will happen?

If the plasticiser is 'leeched out', the material can become brittle.

 

[robinbanks]

Indeed..

a) so coating a PVC cable with something fairly impervious to small molecules like O2 will make it more likely that larger molecules like C24H38O4 will be encouraged to leach out, embrittling the cable?

and

b) so what?

 

[opps]

Surely the op could wipe silicone grease (or similar) on the cable?

 

[JohnW2]

Indeed.. a) so coating a PVC cable with something fairly impervious to small molecules like O2 will make it more likely that larger molecules like C24H38O4 will be encouraged to leach out, embrittling the cable?

I have no idea, but I'm not at all sure "small molecules like O2" have got much/anything to do with it. I didn't think that the potential issue was related to 'impervious coatings' but, rather, to substances that could result in loss of plasticiser - but, as I've said, I don't know.

... and .... b) so what?

That's surely fairly obvious, isn't it? If the PVC of cables loses its plasticiser, it may crack if flexed etc.

Having said all that, over the years/decades I have painted plenty of PVC-sheathed cables with a whole variety of types of paint, and have never been aware of any significant resultant problem.

 

[morqthana]

Indeed..

a) so coating a PVC cable with something fairly impervious to small molecules like O2 will make it more likely that larger molecules like C24H38O4 will be encouraged to leach out, embrittling the cable?

and

b) so what?

Have you ever seen what happens to PVC cables in contact with expanded polystyrene?

 

[JohnW2]

Have you ever seen what happens to PVC cables in contact with expanded polystyrene?

Quite so. I, for one, have 'seen it', and it's quite 'interesting', even though I don't fully understand the chemistry!

 

[robinbanks]

Surely the op could wipe silicone grease (or similar) on the cable?

Well, he’s decided to move them, paint, then refit so it’s decided..

But careful; someone might come along with the “you can’t do that” finger wag and say the silicone could cause the plasticisers to leach out

Have you ever seen what happens to PVC cables in contact with expanded polystyrene?

I wondered how long it would take you to invoke that. Go do some more research on it is before leaning on it as your primary argument for an unrelated substance that doesn’t contain the material at hand.

Your argument is a non sequitur

 

[JohnW2]

I wondered how long it would take you to invoke that. Go do some more research on it is before leaning on it as your primary argument for an unrelated substance that doesn’t contain the material at hand. ... Your argument is a non sequitur

I imagine his point was that contact with some 'substances' (of whatever nature) can harm plasticised PVC, rather than that the 'coating' (or not) of the cable with something 'impervious', per se, was a relevant issue?

 

[robinbanks]

“Don’t use things; some other things, some where, can cause some things to happen to them, so perhaps other other things else elsewhere can also cause things to happen”

Mmm. Definitely a useful mantra

 

[JohnW2]

“Don’t use things; some other things, some where, can cause some things to happen to them, so perhaps other other things else elsewhere can also cause things to happen” .... Mmm. Definitely a useful mantra

You seem to be consistently blind to and/or intolerant of views other than your own, and I'm not sure that your sarcastic style does anything to make your comments be taken seriously. You also seem fairly selective about whom you choose to criticise.

The fact is that contact with various substances can have a detrimental effect on plasticised PVC. As I understand it, the interaction is not so much chemical as 'physical' PVC is pretty 'chemically inert', but substances having a greater affinity for the plasticisers can 'leach' those plasticisers out of the PVC (without any 'chemical reaction', per se), rendering it brittle; expanded polystyrene is notorious for this, but similar can happen with other substances, including various organic solvents.

For these reasons, Prysmian, one of the largest and most respected manufacturers of PVC cables, (to name but one) advise against painting PVC-sheathed cables with oil-/solvent-based paints. I'm no chemist, but looking at the contents I suspect that Hammerite products might be something one would be particularly wise to avoid.

 

[morqthana]

I wondered how long it would take you to invoke that. Go do some more research on it is before leaning on it as your primary argument for an unrelated substance that doesn’t contain the material at hand.

Your argument is a non sequitur

My "argument" very much follows what you wrote. Nowhere will you find me saying that painting the cables will, or even might, cause problems.

What you will find is me replying to what you wrote.

Let's look again at the sequence of posts, shall we?

If the plasticiser is 'leeched out', the material can become brittle.

Indeed..

a) so coating a PVC cable with something fairly impervious to small molecules like O2 will make it more likely that larger molecules like C24H38O4 will be encouraged to leach out, embrittling the cable?

and

b) so what?

Have you ever seen what happens to PVC cables in contact with expanded polystyrene?

“Don’t use things; some other things, some where, can cause some things to happen to them, so perhaps other other things else elsewhere can also cause things to happen”

Mmm. Definitely a useful mantra

How about this useful mantra:

Stop trying to pretend that when JohnW2 said "If the plasticiser is 'leeched out', the material can become brittle" you didn't say "so what?"