Former 3M/Scientific Anglers chief line designer and all-around fly fishing guru Bruce Richards discusses fly line manufacture, the Sage Casting Analyzer, and why all those new rods are so darn stiff.
Podcast Excerpt: “The basic process is simple. Use a braided or some sort of nylon core — almost all lines are made on nylon cores — and that core is run through an adhesive primer, because PVC doesn’t stick to nylon, so you have to put a binder between the two. So then you have prime core material. Then that runs through a bath of PVC, which is a very viscous liquid. Then that runs through a sizing die with a variable orifice that opens and closes to give you the diameter of the line, which correlates to weight. And then it goes into a curing oven that thermal-cures the PVC, and there you have a finished line.”