# DIY double glazing..silica gel



## RogerS (30 Aug 2011)

I remember reading about someone making their own double-glazed units and IIRC organising their own silica gel to absorb moisture. Can't find the link and so was wondering if anyone had any views as to amount of silica gel to use. It's for a garden cold frame and so looks of the packaging unimportant.

Thanks


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## Digit (30 Aug 2011)

It was me Rog, I finally got started this week. As to the amount, no idea, my plan is to put some in and see how I get on.

Roy.


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## Digit (18 Sep 2011)

The job progresses Rog, I still haven't found a sutable container for Silica Gel but I have found out that the suggested amount is 5gms to the cubic foot of air volume.
Hope that helps. The seal I am using is 5mil Bubble from Reddiseals, £15/50mtr.

Roy.


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## madmungo (23 Mar 2012)

I know you posted it ages ago... but in case you have not got round to it yet, I was pondering this tonight as i have some corner windows to make in the triangular section of a lean-to conservatory i am building. Getting bespoke triangular double glazed panels seemed like it was going to be costly. As i dont need them to be anything special, I think the DIY way is the best option. a basic frame and then pin them in place and sealed with silicone will suffice. Anyway, on to my point, i read your posts and thought about the best way to add silica gel crystals. 
My plan is such: To get two bits of glass, bead around the edge of one of the faces with silicone sealant. While it is sticky, sprinkle the part of the silicone bead with silica crystals from a 'do not eat' sachet, that you get in most computer type packaging. I will only sprinkle the inside face of the bead, so basically, pour it on the glass and, keeping it horizontal, shake it back and fourth. Then dust off the glass if any has stuck to the pane, taking care not to touch the wet silicone. Or leave it till later and do it then. 
Then when it has set, create a tiny bead on the second glass sheet, and lay the sheets together, so the wet silicone bead, seals with the first one, which is now dry. 
I also thought about leaving a small un-beaded gap of about a cm, in two opposing places. and when you have a fully set, double glazed pane, use an air duster to blow in compressed HFC gas which will serve better than any humid air that was caught inside. Squirt a good lot in until you can guess it has blown all the regular air out the opposing gap, and then quickly seal both gaps with a blob of silicone. 
Finally tape around the edge with duct tape to prevent cutting yourself on the glass edge, and also to prevent damage to the silicone when installing. 

Anyway, that is what is in my head. I shall give it a go next week once i have got the polycarbonate roof on, and i know what size gaps i need to fill.


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## Digit (23 Mar 2012)

I don't see why it wouldn't work, but I will say that I doubt that it will last as long as two separate glasses.
In extreme cases you can have one sheet of glass at 20 C and the outer at minus 15 C, this is what causes the break down of sealed units. With two independent glass sheets the problem doesn't arise.

Roy.


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## nev (24 Mar 2012)

madmungo":sh1ceiq8 said:


> I know you posted it ages ago... but in case you have not got round to it yet, I was pondering this tonight as i have some corner windows to make in the triangular section of a lean-to conservatory i am building. Getting bespoke triangular double glazed panels seemed like it was going to be costly....



Obviously depending on size, probably not as much as you imagine. I decided to put some 30cm x 20cm glazed units in a solid door and they were about a tenner from my local upvc firm. I also bought two unglazed window frames for my shed about 1m x1m and all the DG units for the two was less than 50 quid.


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## andyacg (24 Mar 2012)

in the recent past i used to make dg units. we sold clear float glass units at £20 psqm + vat with a 25 % surcharge for shaping. triangles etc. toughened was around 32 plus vat plus surcharge


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## madmungo (24 Mar 2012)

Wow, cracking replies. Thanks. I had not thought of the expansion difference. 

And thank you for the price heads-up, it may indeed be the best option. I shall definitely get dg units quoted when I find out the sizes 

Thanks 

(edited as my phone thought it's choice of spelling was better than mine!)


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