How to fix toughened glass to steel frame?

[Nick]

I've an old single glazed Crittal galvanised steel framed, leaded light, window. This is used as a door to utility room and garden. Unfortunately one of our dogs in a fit of excitement has put out one of the panes. On inspection the entire glazing is generally in poor condition. The plan is to remove all existing glazing and replace with a single sheet of 4mm toughened glass. Approx size 1335 x 540mm. Glass fits into a 20mm (3/4") rebate. We have a decent glass company locally and I was pleasantly surprised by their quoted price. I would prefer to fix glass to frame as easily, and firmly, as possible. The Crittall frame has some flexibility. I presume that the glass would add some rigidity. I have little knowledge of glazing but presume that linseed oil putty is not the stuff for the job. The glass company suggested that a bed and beading of silicone (?) would not be adequate. The window frame will be removed from hinges for removal of old and fitting of new. Any ideas on how to fix the glass to the frame please? Nick.

[newshound]

ISTR that there was a non linseed oil putty substitute for use with Critalls, although I don't actually see why. I've used ordinary putty without trouble in the past, because I had it to hand. I'm a bit bothered by the description of the frame being flexible, in my experience they are usually very rigid; is there a cracked weld at a corner somewhere? I don't see why silicone would not work although you might want to use "spacers" to stop extrusion.

[Ivan Dobsky]

I expect the putty would be okay once the oil has dried out just leaving mostly chalk.

[Peter Percival]

Ask here:

[Nick]

Thanks for that. The amount of flexibility is not great. No cracked welds. It's a fairly large frame and the framing sections are quite small. About 1 x 1 inch, you'll know what I mean. Flex is diagonal from top right to bottom left and vice versa. I think the original glazing would have aided the rigidity but that has now failed. AFAIK this window was installed in 1919, it hasn't done too badly. It is used every day and probably the most used door in the house. Says something for the quality of old fashioned British manufacturing perhaps.

[Cash]

Metal Casement putty - along with glazing clips (there may be some already in the frame so take to recover them when you remove the old putty.

Cash