Newbie question about glass

[scubaguy]

Hi All,
Very new to this, in fact I am taking a beginners course in 3 weeks.
Been doing a lot of research and have a few questions.
I understand what coe means but what do the numbers represent ie coe104 or coe96? Do the different glasses have a different melting point, is one harder than another. Do you find a difference working with certain glasses.
Im sure all of this will come to light when I take the class just trying to educate myself before hand. Are there some glass of different coe that you can mix or do you need to stay with the same coe
Cant wait to get started, this looks like a very plesant addiction
Brian

[neagle]

http://www.warmglass.com/COESummary.htm

Welcome! There are many good threads on all these questions. Just search for the different information.

Read all the information you can. Also, Youtube has incredible lampworking videos.

[Rose]

For the most part you never mix coe's. Some frits are furnace glass and we sometimes add a small amount and it mostly works as it has a higher lead content, if I remember correctly. But what you need to know right now is to keep the coe's separate. Yes, different glass does feel and act different to work with. That's the fun!

Some glass is stiffer that others. Bullseye is stiffer and boro is the stiffest. Boro takes the highest heat to make anything.

Your are off on a great adventure!

[Alaska]

An excellent explanation and example is on page 212 of Volume I, Contemporary Lampworking, 3rd edition by Bandhu Dunham. Or give Wiki and Google a try.

The number represents how much the glass will expand when the temperature is raised 1 degree C. Thus 104 x 10-7th cm/cm/C. (That is ten to the minus 7th.) Or in this case 104 ten-millionths of a centimeter.