Monday, 20 June 2016

Glass thickness

I was at an old chapel recently which was converted to flats perhaps ten years ago. An accident had revealed something that anyone living in such a building might want to be aware of.

A window, some six feet off the ground, had been broken, and the owner had kept a piece of the blue glass which she would like me to replace.

I noticed it was very thin; in fact, it was one-sixteenth of an inch (about 1.5mm) thick. (The Methodists who built the chapel clearly didn't believe in spending any more on luxuries like glass than they really had to.) Being over 1500mm above the ground the building reg rules about thickness won't actually apply, but tapping some of the (unbroken) windows around the property we came to the view that there could be some glass of that thickness at a lower height elsewhere in the building.

The coloured glass I normally use is 3mm (one-eighth) thick; in some high rick places 4mm is preferred (or required, in Building Regs).

The thinner glass breaks very easily.

I have a suspicion that glass thickness had not been on the list of things that were thoroughly checked by Building Control when the conversion was done - it is difficult to tell glass thickness when it's in a window! The piece will have to be replaced with 3mm glass, it's almost impossible to get hold of anything thinner these days.

The problems of matching colours

I did the necessary work on the broken Victorian panel (see Feb 2016 post) recently. The glass we had ordered was indeed a close - but not perfect - match, the three replaced lights can be readily identified in the photos I took on my phone (which perhaps bring out the difference more than is apparent when actually looking at the panel).

Closer examination of the glass in question did lead me to wonder whether it was the same as the glass I had removed, or the matching pieces at the other end of the panel.

I have left the customer a piece of the yellow glass I used, just in case she wants to replace the bottom left light; however, when reviewing the photos I took in February, I noticed that that piece was slightly darker than those I had replaced anyway.

The glass will, of course, weather a little, and I was not able to polish the panel aggressively while the cement was still soft; once it has hardened some Mr Sheen and an old pair of tights will work wonders. I will still notice the difference in colours, but possibly others won't!

Sunday, 12 June 2016

Lettering on glass

I've been working on a piece ( a gift - photos of it will follow once the recipient has it) incorporating some lettering.

Large letters - 2 inches high or more - I tend to cut in glass, using copper foil to solder them into the panel. There are some in the piece.

In this case it's was also necessary to use smaller lettering, using paint or similar to add the required text onto the glass. Traditionally, this would be done in enamel and fused into the glass with heat; modern technology does provide alternatives, one of which I've been experimenting with.

Many of us have used Letraset lettering on paper in the past (younger readers may not be so familiar with it, now that Microsoft Word and the like are used to produce reports).

The photo below shows two tests of black Letraset, applied using a burnishing tool onto white glass.

In both cases the lettering didn't quite go down perfectly, but did give an acceptable effect; however, I needed to protect the delicate lettering with varnish. For that on the left I tried a squirt of gloss polyurethane, on the right I brushed on some clear nail varnish. Both varnishes did soften the lettering enough to cause slight runs, but the final effect of the spray was more than acceptable - that's what I'll be using to protect the text on the final piece (which is complete, apart from the text - I will apply the letraset now the panel has been fully soldered). The nail varnish can be returned to the bathroom shelf!