Pattern Precision and Foil Width

by Tom Van
(Lynchburg, VA)

As an engineer and woodworker, I appreciated your comments about the need for precision when cutting out the pattern and foiling. I have two questions about pattern and glass cutting size in relation to foil thickness. I'm using Edco 1.25 mil foil (thanks for the recommendation about Edco, it's great stuff).

First, when I cut rectangular border, I'm using my Morton system, not a pattern. How much should I undersize my glass cuts to account for foil thickness and ease of assembly? It seems like taking 1/32" off each piece might leave a pretty big gap between the pieces to fill with solder.

Second, for curved pieces, I purchased a James EasyCut foil pattern shear. This cuts off a 0.05" slice, which seems like a really big gap between each piece. Pattern shears seem like a great time saver, but I wonder if I am going to waste all the time savings filling gaps when I am soldering. Is this why you hand cut your pattern pieces?

I would appreciate you lending me some of your experience here. Thanks for the great site. I've found your recommendations spot on so far.

Answer

I assume you have a cartoon that you're constructing your panel on. Measure the width of the border pieces, inside the black lines, and set your Morton System to that measurement. As long as your lines on the cartoon are only as wide as the line you would make with a medium ball point pen, you should be spot on.

I'm not a fan of pattern shears. I've always found them to be more of a hindrance than a help and yes, you're right, they take off too much. There are two ways you cut more precisely. Hand cut your Pattern Pieces or Trace Cutting. Trace cutting has a bit of a learning curve, but once you master it, I'm sure you'll find it the easiest and most precise way to go.

Don't worry so much about the thickness of the foil. The minute difference between the thicknesses isn't going to have much bearing on the gap you leave between your glass pieces. When you're looking at millimeters, the difference between 1mm and 1.5mm is only about a hairs width.