Paint to use for vinyl plastic material?

[sammy7boy]

Hi folks. I'm brand new on here hi everyone.

In my classroom (i'm a teacher) i have two large south-facing windows, both about 2m x 3m. The windows are covered with black vinyl blinds, which have to be kept permanent rolled down because of the glare on whiteboard.

When it's sunny the black blinds become the ultimate solar radiators! I only started teaching at the school in September, but the problem was so bad in May/June/July last year that the then teacher resorted to covering the windows with aluminium foil (glued onto the glass) to help stop the room becoming a complete sauna when the sun was out. The first thing i did when i took over the classroom was to rip the foil down because it was peeling off and looked absolutely crap, not to mention the fact when the windows were open all you hear was the sound of foil crinkling in the breeze.

Now that the sun is getting stronger again i'm looking for a better solution for preventing the sun from heating the room up severely. I've looked into getting reflective film to cover the glass, but it's pretty darn costly to get 12 metres squared of it. Replacing the blinds with white and instead of black ones would make a lot of difference, but the school has been dragging its heels over the idea, plus that would be just as expensive if not more than the reflective film idea.

So much pondering led me to the idea of simply painting the outward facing side of the blinds white. I could do this easily over the Easter holidays in just an hour or two. This leads me (sorry this has been a really long post!!!) to my question: what paint should i use to do this?

The blinds are made from that sort of fake leather vinyl plastic material. It's been quite difficult for me to get an idea using Google because as soon as you put 'vinyl' and 'paint' together in the search bar you get lots of hits for vinyl paint which is NOT what i'm looking for!

I'd prefer to apply from a tin using a brush or roller, as opposed to spraying. If anyone can recommend a brilliant white paint which is up to the job - i will probably need a couple of litres - then that would be cool, literally.

Thanks!

 

[footprints]

How about Fablon (sticky backed plastic Blue Peter style) on the back of the blind?

 

[Flyboytim]

"Brilliant white paint" may not be the best route to go - the "brilliant" part (brightness enhancers) may actually absorb some very short wavelengths and re-radiate at lower wavelengths - in other words, they contain fluorescent pigments to enhance the whiteness. This will also have a cost in radiating heat within the paint coat.

Whitewash on the glass is a traditional method - the lime in the wash will reflect most wavelengths equally without any brightness enhancement and the window glass itself will radiate heat 50% outwards and 50% in. Therefore you get both a reduction in light and heat radiation at the glass surface itself, but not a total block.

"Coolglass" (Bayer) is the name of one product you can find in garden centres designed for keeping greenhouses cooler during the height of summer. Can be painted or sprayed on. Contains titanium dioxide, and is sold in packs for less than £5 for covering up to 15 sq metres.

Traditional interior lime washes are made from quicklime (calcium oxide) slaked with water which makes calcium hydroxide which then reacts with carbon dioxide from the air to form calcium carbonate. This may be polished off the glass when no longer required.

Exterior whitewash contains milk proteins (casein) as a binder.

This sounds like a class chemistry project to me!

 

[sammy7boy]

Thanks for the fantastic advice Flyboytim and footprints. Both suggestions look excellent.

£5.50 including delivery for enough Coolglass to cover the windows is an absolute no-brainer! I've just ordered some in and will be popping into school when it arrives to apply it to the windows.

The Fablon idea works out at at least £30/£40 to cover the blinds in white sticky back plastic, and quite a lot more than that for chrome/silver. I'll see how the Coolglass works out and look into adding Fablon to the blinds if i need to take the heat shielding to the next level!

Many thanks guys
Sam

 

[footprints]

Good luck with the homework
If you don't get it done in time it's no good saying the dog ate it