11-03-2016, 12:47 PM
I was told years ago that glass is a supercooled liquid, whatever that is, and that it continues to move. Certainly really old windows are thicker at the bottom than the top. Defies logic but there you go.
CRTs are mostly lead glass, I don't know about valves, but most blown glass is lead, cast glass can be crystal as I understand it.
Straight cutting old window glass is difficult because the surface is contaminated. We used to polish the surface with an abrasive and then it cuts much like new glass.
I have re-necked lots of old CRTs and had no particular problems but using many thousands of pounds of glass lathe does make life simple!
The re-gunning trade did not seem to have a problem, and some of the tubes they worked with must of had many years of use.
Will have a go when I get back, something else to do, retirement is so hectic.
CRTs are mostly lead glass, I don't know about valves, but most blown glass is lead, cast glass can be crystal as I understand it.
Straight cutting old window glass is difficult because the surface is contaminated. We used to polish the surface with an abrasive and then it cuts much like new glass.
I have re-necked lots of old CRTs and had no particular problems but using many thousands of pounds of glass lathe does make life simple!
The re-gunning trade did not seem to have a problem, and some of the tubes they worked with must of had many years of use.
Will have a go when I get back, something else to do, retirement is so hectic.
Boater Sam.
