Quote:
Originally Posted by stusnyder
I don't see any reason it would'nt be.. What exactly did they use to bond the glass parts to the metal in the first place?
|
The glass is FUSED to the metal parts. The process heats the metal parts to the temperature needed to melt glass to a soft molten state around 1500C for soda lime glass used in a crt. When both the metal and the glass are up to temperature, the glass will bond to the metal. Special manufacturing process are used that have many gas jets focused on the glass to metal joint while the parts are rotating and being heated by the flames. It is likely that the pre-molded glass components are pre heated to a temperature slightly below the melting point so that there is not a large differential between the temperature of the molten joint and the rest of the glass pre-formed body of the crt. If you do not heat glass in a pretty much uniform manner, you will cause the glass to fracture.
A good example of what can happen if you don't heat glass uniformly is the couple of people who tried to remove cataracts from a 21FJP22 by using infra red heat lamps or a heat gun to heat the face of the crt; and by so doing created an large differential in the temperature between the front of the tube to the back of the tube, and thus causing an implosion. It is a big no-no to heat glass in a non uniform manner. In a crt rebuilding facility, the cataracts are removed by placing the entire tube in an oven and heating the entire tube in a uniform manner to a point where the PVA bonding adhesive becomes soft and then removing the safety glass while the tube is hot. Then the tube is allowed to cool in a uniform manner. When you remove a cataract in this manner, it is a fairly safe process and fairly simple.
12-21-2011, 01:44 PM
Hybrid Mode
