On 04/02/2020 11:59, Adam Funk wrote:
On 2020-02-03, Dave Liquorice wrote:

On Sun, 02 Feb 2020 22:56:42 +0000, Chris Hogg wrote:

I have a lean-to PVC conservatory on the side of my bungalow, facing
west. On the north side, where it doesn't get any sunshine, the PVC on
the outside is going green with algae. I plan to pressure wash it, but
is that likely to damage the surface of the PVC?

Almost certainly, pressure washers are vicious things. I don't care
what they say about UV stable all the uPVC that I've seen after being
outside for a few years has a thin "bloom" layer of degraded plastic
on the surface. It's pale gray very noticable on black, not so much
on white...

Should I just use a bucket and brush?

I would and maybe look at the uPVC "revivers" that you can get to try
and restore a smooth finich that will reduce the footholds for algae.

What's in those, & how do they work?

I think that the good ones contain solvent and effectively soften,
smooth and then as they evaporate, re-harden the surface of the uPVC.

I don't remember the make, but I used to have a can of the stuff my
uncle (who frequently worked installing door and windows) used to use to
remove any marks from both old and freshly installed units. It was very
effective.

SteveW

On 04/02/2020 22:15, Steve Walker wrote:

I think that the good ones contain solvent and effectively soften,
smooth and then as they evaporate, re-harden the surface of the uPVC.

I don't remember the make, but I used to have a can of the stuff my
uncle (who frequently worked installing door and windows) used to use to
remove any marks from both old and freshly installed units. It was very
effective.


Mostly Acetone


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Steve Walker wrote:

I don't remember the make, but I used to have a can of the stuff my
uncle (who frequently worked installing door and windows) used to use to
remove any marks from both old and freshly installed units. It was very
effective.

For cleaning PVC, I've used this

https://toolstation.com/PVC-cleaner/p31464

it doesn't claim to "restore" the surface, but I'd be wary of using a
pressure washer.

Be careful how much of the stuff you breathe in, if working up a ladder
probably best to use a vapour filtered half-mask, or do take frequent
breaks ...

On 04/02/2020 23:58, alan_m wrote:
On 04/02/2020 22:15, Steve Walker wrote:

I think that the good ones contain solvent and effectively soften,
smooth and then as they evaporate, re-harden the surface of the uPVC.

I don't remember the make, but I used to have a can of the stuff my
uncle (who frequently worked installing door and windows) used to use
to remove any marks from both old and freshly installed units. It was
very effective.


Mostly Acetone

Yes, that's definitely a major constituent.

SteveW

On 2020-02-04, Steve Walker wrote:

On 04/02/2020 11:59, Adam Funk wrote:
On 2020-02-03, Dave Liquorice wrote:

On Sun, 02 Feb 2020 22:56:42 +0000, Chris Hogg wrote:

I have a lean-to PVC conservatory on the side of my bungalow, facing
west. On the north side, where it doesn't get any sunshine, the PVC on
the outside is going green with algae. I plan to pressure wash it, but
is that likely to damage the surface of the PVC?

Almost certainly, pressure washers are vicious things. I don't care
what they say about UV stable all the uPVC that I've seen after being
outside for a few years has a thin "bloom" layer of degraded plastic
on the surface. It's pale gray very noticable on black, not so much
on white...

Should I just use a bucket and brush?

I would and maybe look at the uPVC "revivers" that you can get to try
and restore a smooth finich that will reduce the footholds for algae.

What's in those, & how do they work?

I think that the good ones contain solvent and effectively soften,
smooth and then as they evaporate, re-harden the surface of the uPVC.

I guess you need to be careful not to overdo it!


I don't remember the make, but I used to have a can of the stuff my
uncle (who frequently worked installing door and windows) used to use to
remove any marks from both old and freshly installed units. It was very
effective.

SteveW

On 2020-02-05, Andy Burns wrote:

Steve Walker wrote:

I don't remember the make, but I used to have a can of the stuff my
uncle (who frequently worked installing door and windows) used to use to
remove any marks from both old and freshly installed units. It was very
effective.

For cleaning PVC, I've used this

https://toolstation.com/PVC-cleaner/p31464

it doesn't claim to "restore" the surface, but I'd be wary of using a
pressure washer.

Be careful how much of the stuff you breathe in, if working up a ladder
probably best to use a vapour filtered half-mask, or do take frequent
breaks ...

Or do it when there's a breeze (but not too windy).