Etching/frosting/painting the glass....yay or nay?

16 years ago

I'm about to start building a glass greenhouse out of recycled windows, doors, etc... Polycarbonate was my first choice but its price has ruled it out as an option for me. I really like the fact though that the polycarb diffused the light and wasn't completely clear and I'd like suggestions on how to incorporate that into my glass greenhouse. Isn't the concensus that diffused light is better for most greenhouse plants?

Does anyone know if etched glass on a large scale would diffuse the light similar to polycarbonate or would it be too opaque? I was considering this primarily for the roof and possibly leaving the sides see-through. I like the idea that the etched glass would be permanent as opposed to a paint or whitewash that has to be reapplied, but I'd like to hear of others experiences with any of these methods.

What brought all this on is I came across some old double-pane glass windows today that I thought simply needed cleaning. However the "dirty" areas were between the panes and after reading up about double pane windows I learned that this is common for older double panes whose rubberized seal has been compromised over the years. Condensation and outside air seeped into the space between the panes which was originally probably filled with argon gas when it was factory new. Even if you are able to separate the panes which is difficult it's not just a matter of cleaning the inside of the glass. I'm told the milky film on the inside is the result of a chemical reaction that occurred naturally over the years and the milky film I'm seeing is actually a chemical etch in the glass that can't be cleaned off. Well, I took apart my first double pane window today to find out for myself and they are indeed correct. I tried every cleaner I had including brake cleaner which will take off just about anything and nothing works.

It really isn't bad in that it's not blocking much light, it just looks unattractive because the slightly milky areas are uneven, streaky and will always look like they need to be cleaned which will probably drive me nuts.

I did some small-scale etching when I was younger and I've been researching Etchall Acid Etching Cream. You can buy it in 32 oz bottle sizes and it's reusable. You coat the glass to be etched and after the time has elapsed you squeegy the cream off the glass and back into the bottle to use again and again. I thought perhaps if I did this process to the side of the window that will be facing inside the greenhouse, it would not only hide the unsightly streakiness inside the double pane but also diffuse the light.

Any thoughts on this? Does etched glass block too much light? Any reason why I'd need to etch the exterior side of the window as well? Or is this just a silly idea?

Sincerely,

Danielle

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Comments (4)

mudhouse_gw
16 years ago
I thought this was an interesting question. IÂll post some thoughts in the hopes it will spark comments from others.

I found one thread that mentions frosted glass being used in a conservatory:
Opinions on Frosted Glass?

Frosted glass does diffuse the light, and diffused light is beneficial. In spite of that, I couldnÂt find much information on the Internet regarding the use of frosted or etched glass in greenhouses.

So, my guess (just a guess) is that frosted or etched glass is not widely discussed as an option for glass greenhouses because it doesnÂt negate the need for shadecloth or whitewash in sunny situations. If it provided a definite advantage over clear glass, it seems like it would be easier to find more references to its use. I donÂt see why it would be too opaque.

Maybe itÂs not discussed much because the people who choose glass greenhouses also enjoy seeing in or out; if they didnÂt care about that, they might as well choose polycarbonate.

That being said, I think you have a good reason to work with this idea. If it helps you transform recycled windows into something that pleases you when you look up at themÂinstead of being annoyed by streaksÂthen why not?

The only downside I can see is you might find you still have to do something additional to diffuse the sun coming into your structure. (I wish I had the experience to wager a guess about that, but I sure donÂt.)

IÂd be tempted to try one window (or a scrap piece of glass) to see if I liked the results. Now, if itÂs a double paned window, and you frosted both pieces of glassÂwould that diffuse the light even more? I donÂt know...

Maybe someone that knows more about light diffusion than I do will pipe in here.
maxkoreen
16 years ago
I used to work at a conservitory/greenhouse made of glass. Twice during the summer the outside of the structure was painted with white paint to cool the interior. Worked well.
jbest123
16 years ago
Why not Bon Ami on the inside so the rain won't wash it off? Then in winter when you need more sun, simply wipe it off. Cheap and easy.

John
Danielle Harrison
last year
last modified: last year
Im also interested in doing this, I worked with glass at university and did sandblasting designs by layering the sandblasting. You can definitely get more opaque with more layers but there is a limit. I really like the idea of reusing glass panes to make a green house and etching or sandblasting for a permanent solution, I don't see why it would be less effective at diffusing light than plastic, as the light is being refracted through the etching.

Edit: You also get the added bonus of adding a custom deign :)