The Talking Machine Forum — For All Antique Phonographs & Recordings

The ½" glass is a sizable chunk of weight, which might explain the flattened grooves. I would not use so heavy glass if I were you. The ¼" has always worked fine for me.

Henry wrote:The ½" glass is a sizable chunk of weight, which might explain the flattened grooves. I would not use so heavy glass if I were you. The ¼" has always worked fine for me.

I went with ½" because I was super paranoid about breaking the glass in the oven. I'll try ¼" on top if adjusting the temperature higher doesn't work. Thanks for the tip!

Don't think broken glass will occur as long as the temp is moderate. I usually just turn oven on to "warm" and no higher. Also, by placing the "sandwich" in a cool oven, then turning on the heat, it warms up gradually and thus avoids thermal shock, which might occur if it went from room temp into an already hot oven.