These are impossible, you say, these long gradual curves and I hate this job and why did I ever get into this in the first place. Well, we didn't get you into this job but maybe we can help get you out of trouble.
There are two types of "long slow curves," those that will be viewed from the side (where it looks like a curve) and those that will be viewed end-on (following the curve of a building, and looking like a straight line). If you have one that gets looked at from all directions, forget it, there's no help for you.
There are two hints here: one for pulling the glass into place and one for keeping it all in plane (avoiding any "corkscrewing").
If the curve of the pattern on the bench arcs away from you like a smile (no smiles allowed) turn it around. Put on a frown of serious concentration and you might find that bending the curve this way is easier.
Heat the glass a minimum amount, and when it's on the table actually pull out, sideways, like you're trying to stretch it out,rather than just bending the glass in the general direction of the pattern. You haven't heated it enough to stretch it significantly and the pulling helps to avoid small kinks.
If this is an architectural-type curve and the electrode will double-back into the same plane as the curve itself, try this: After the first heat is done and cooled, before going into the next heat of the curve make the double-back. This gives you a point of reference. In order for the curve to "corkscrew," that double-back will have to twist or come off of the table, and as long as your hand is keeping it flat on the table, presto, One Plane. Are we happy now?
If this is a "normal" curve, one where the electrodes come out of the plane, you can still use this technique. It takes a little more glass, enough so that after leaving plenty for your future double-back you make a 90-degree bend in plane.
Click here for 6K image of Architectural style curve
Click here for 10K image of Normal style curve
Copyright 1989 THE NEON NEWS
Published by Ted Pirsig & Val Crawford Email: firstname.lastname@example.org