Shading

[ChrisR]

Suzanne Topsy very kindly sent me a few sachets she had spare and I just placed an order with Ragamala's link so thanks to both.

The other suggestions are of interest.....I wonder how long Dave's whitewash would take to wash off? And as my water butt fills from the greenhouse roof I suspect it might make the water too alkaline?

Anyone trying titanium oxide/water mix please report back on results.

[ragamala]

Looks as if he is actually using it for a cactus house:-

https://www.youtube.com/watch?v=WYGVDcI_ZUw

I'm a bit confused there -
This 34 second clip talks about using a "special kind of whitewash", for which we have no name or recipe, which makes it sound as if it is like Coolglass, and the guy talks about not using traditional whitewash these days?

[ragamala]

Suzanne Topsy very kindly sent me a few sachets she had spare and I just placed an order with Ragamala's link so thanks to both.

The other suggestions are of interest.....I wonder how long Dave's whitewash would take to wash off? And as my water butt fills from the greenhouse roof I suspect it might make the water too alkaline?

Anyone trying titanium oxide/water mix please report back on results.

Thanks Chris.

I have just ordered some titanium dioxide (effectively the same as oxide in powder form) and will try this out when it arrives, both in a plain mix with water and in a mix with water and wetting agent, eg washing up liquid. I shall post the experiment results. I'll also try a plain traditional whitewash of slaked lime, and see how that compares.

[dalesmatt]

I didn't actually know there was something as trendy sounding as coolglass, but thanks.

Feeling like a complete bodger I just watered down some cheap old half used matte emulsion out of a rusty tin. though stippled on in nice wobbly lines with panache a la the late Victorian Kitchen Gardener, Harry Dodson
I think my Dad did the same about 6 years ago but its slowly worn off at the worst weathered end.

[Terry S.]

But Matt, you want to remove the shading in the winter when light for our plants is at a premium. As you indicate in the observation about your Dad's greenhouse, paint sticks there for a long time. The great advantage of Coolglass is (or was?) that it stays on even when it rains (but not in a hail storm), but can easily be removed by just rubbing it whilst dry with something like an old J-cloth. I do suspect that there is something added to the Titanium oxide in Coolglass to make it stick.

[dalesmatt]

Thanks Terry;

Cheers for the observation, I'm not sure my Dad had ever particularly bothered with removing it as the greenhouse is sighted oddly for the area in the front garden with its south facing aspect, it gets quite warm in there on sunny winter days, although I do appreciate what you are saying about the light.

It would be totally hidden from all but morning sun sited in the back and I worry a bit about security and people seeing what is in there so the shading reduced what passers by can see! (back is where there is more acceptable space but that's another story)

I ought to have made it clear that I do not paint the roof (its only a 6x6!) which has a decent bubble wrap layer, I think the gentle rubbing of passing by rubs the paint off as the year progresses - there is a hedge the same height as the greenhouse walls that gets cut and is only 3 feet away. I will try rubbing off the thinned paint in the late autumn with a cloth or green scrubbing pad and see what happens.

[ragamala]

Since we just had a second batch of heavy rain, time for an update on different shading in my experience after a limited test.

Pics below show as of today -
1 titanium oxide mixed in water
2 titanium oxide with added washing up liquid as binder
3 plain slaked lime whitewash
4 coolglass (applied much earlier).

The first application of the plain titanium oxide mix didn't go on as well as that mixed with a bit of washing up liquid. But applying a second coat shortly afterwards to increase the shading it seemed easier to build up the coat without the washing up liquid.
Neither went on as easily with good coverage as the slaked lime mix which provided quite dense shading immediately.

Heavy rain affected both the titanium oxide mixes, but not the whitewash. The titanium oxide mixed with a bit of washing up liquid fared better than that without.

Both the titanium oxide mixes were easy to remove when dry. The whitewash was not too difficult either but a little more rubbing with a cloth was needed.

Coolglass has remained pretty much as applied after the rain, and is easy to wipe off when dry, I think.

For good shading I would go perhaps for whitewash when my Coolglass runs out, as I have no difficulty of access to the glass when I need to remove it.

T. oxide

T. oxide+wup liquid

Whitewash

Coolglass

[Peter]

I have large bubble in the roof. The east facing wall (my Copiapoa side) was Coolglass sprayed about eight years ago. Never seen reason to remove it by wet brushing.