Terminology for degrees of fusing

Can anyone describe what a contour fuse is?

No one can satisfactorily describe, to a high level of acceptance, what a contour fuse is. For me it is just before a full fuse. That will not be acceptable for many, just as describing something as a rounded tack fuse is not a contour fuse for me.  A sharp-edged tack fuse is sintered glass. This will be important to observe as you move to other glass processes such as pate de verre.

There is not yet an accepted terminology and will not be as long as people choose to invent new descriptions for what are essentially the same things.

The closest you can get to a sensible range of descriptors is in the Bullseye document "heat and glass" where the temperature ranges are the important constants.

  

The fourth column of this document gives names for the process. It would be a good idea to adopt these terms, as Bullseye is the company doing the research in the area of kilnforming.

Bullseye terminology gives the following:

A slump or bend occurs in the 540C – 670C range

Fire polishing and sintering occur in the 670C – 730C range

Tack fusing (a rounding of edges) occurs in the 730C – 760C range

A rounded tack fusing that begins to sink into the base glass occurs in the lower end of the 760C – 816C range.

Contour fusing occurs in the middle of the 760C – 816C range.

Full fusing (flat) occurs at the upper portion of the 760C – 816C range.