1. Home
  2. Glass Crafts
  3. Gas lamp glass

Gas lamp glass

I have been asked if I can make some replacement glass for an old gas lamp. The lamp forms a truncated cone about 380mm (15") high, 230 mm (9") at the base and 430mm (17") at the top. 3 pieces of glass form the cone and are fixed to 3 vertical ribs joining the top and bottom of the lamp. I have done some straight 'U' shaped glass before but that was to be sand blasted and so the internal surface finish was not an issue, I just slumped it over a sheet steel former coated in kiln shelf wash and it worked perfectly. These items want to be quite smooth and I am not sure how the original would have been done. The only remaining damaged one shows the side of the cone to be quite straight. I wonder about making a form to represent the edges and slumping over this but fear the glass will sag in the centre and so the side of the cone would not be straight. Any ideas how these would have been produced, maybe over a form with a very fine surface so as not to impart any texture on the glass.

Reply to
David Billington
Loading thread data ...

When originally made, they were probably slumped into an iron mold coated with release. They may have been heated to nearly soft and moved like a pizza onto the mold. In modern terms the release has to be coated several times and brushed smooth and slightly dusty. A curved piece of stainless steel is probably your best mold for a smooth curve. You may want to partly slump the piece over rods to pre shape it although a 1/3 mold should not be bad.

Reply to
Mike Firth

David, I have made these from time to time over the years, and they are pain to get just right. So don't try to get perfect in the bending process, make them oversize and trim later. As for the moulds, well, the sheet metal guys have fun making these for me ! : ) BTW, for bending temps, you shouldn't need to kiln wash at all. There are little things to stop pitting etc on the glass too, though sandblasting after is a great effect anyway. Moulds can be s/s (best but pricey) or z/a, even mild steel can be used, if z/a (burn z/a off first) or mild steel, give then a rub before slumping. Regards, Les

Reply to
figjam62

InspirePoint website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.