Silk Fly Line: Manufacture and Care Information

Many people consider Silk Fly Line to be the more traditional fly line when fishing with Bamboo Fly Rods. Brasstown Creek sells Phoenix Silk Fly Lines and we use these beautiful silk fly lines ourselves. Although Silk Fly Lines can be furled (similar to Furled Leader), for the most part Silk Fly Line is braided.

Brasstown Creek sells (and also fishes with) Phoenix Silk Fly Line.  Phoenix Classics makes its line by braiding pure silk filaments together. In order to get the proper taper in the line, they add or remove filaments during the braiding process. Because creating a proper taper requires adding or deleting filaments, a manufacturer can’t make a long run of line.  Consequently, only one line at a time can be made on each braiding machine (often as slow as only 66 inches per hour). After braiding, the newly made silk fly line must be treated to become water resistant.  Treatment also prolongs the fly line’s life. Top quality lines could get as many as a dozen separate coats of Linseed Oil.  The silk requires a drying time between coats of 5-15 days (see “America’s Fly Lines by Victor R. Johnson, Jr.).

Some manufacturers sell the silk fly line without treatment, leaving it up to the buyer to complete the line preparation. This practice usually results in significant savings to the buyer, but requires a lot of effort before fishing the silk. Phoenix Silk Fly Lines receive treatment at the factory and come ready to fish when you get them. Still, we suggest applying a coating of Red Tin Mucilin before starting (we do). Our results with Phoenix Silk Fly Lines are excellent.

Most modern fly line float because the specific gravity of the line is less than one.  Essentially this means a given volume of fly line weighs less than an equivalent volume of water. Not so with Silk Fly Line. Silk Fly Line has a specific gravity greater than one; hence it can be expected to sink. However, when properly treated with a floatant  the line becomes supple and water resistant.  Manufacturers use boiled linseed oil, varnish, a mixture of both, or a proprietary concoction.  Thus the Silk Fly Line rides on top of the water due to surface tension (the same way a water strider stays on the surface).

Being more dense than its modern synthetic counterpart, Silk Fly Line has a smaller diameter that its counterpart of equivalent weight class.  For example, a 5wt Silk Fly Line would have a diameter comparable to a 4wt modern counterpart.  Consequently you get less air resistance and easier pick up from the water.

Even the most scrupulously treated Silk Fly Line eventually absorbs water and begin to sink.  How long you fish before this happens depends several factors.  These factors include the quality of the braided line, the quality of the finish, and how well you have cared for the line before, during, and after fishing. I have been able to fish as long as 7 consecutive hours before my line began to sink, but the time is usually a bit shorter. Your Silk Fly Line must be thoroughly dried before you apply a floatant such as Red Tin Mucilin; doing so before it is fully dry can seal moisture in the fly line and cause mildew or rot. If you don’t have a line dryer, you can simply dry your silk line by unwinding it from your reel in large loops so they will get plenty of air.

Care and Maintenance Tips:

  1. Don’t fish with Silk Fly Line at low temperatures (freezing or below). Ice forming on your guides and tip tops damages the silk line as it shoots through. Furthermore, the line treatment (for example, Red Tin Mucilin) stiffens at low temperatures making casting less effective. I learned both these cautions the hard way.
  2. Keep the line clean, periodically inspecting your Silk Fly Line.  If you find dirt and grit adhering to the line treatment; apply Red Tin Mucilin to your line.  Remember though that too much of it just attracts contaminants.  A note here – in really hot temperatures (such as in a closed vehicle on a hot summer day, the mucilin becomes somewhat fluid.  Consequently, the container may leak.  Yes, I learned that the hard way.
  3. After each day’s fishing, thoroughly dry your Silk Fly Line to prevent mildew and rot. While a fly line dryer helps make this easier, you can simply drape long coils of fly line over whatever furniture you don’t mind getting a little moisture on.  I usually do this in my workshop as I have yet to find furniture my wife will let me get wet. Don’t forget to dry the fly line backing while you are at it. If you don’t, then the moisture in the backing re-dampens the Silk Fly Line when it is re-wound on your fly reel.
  4. After your Silk Fly Line dries completely, apply a thin coat of Red Tin Mucilin to the fly line as you wind it back onto your reel. Apply this in small increments, maybe three or four feet of line at a time. Then wipe on the Red Tin Muciln with its accompanying pad then wipe off any excess. I do this to the full length of the fly line. If it is a few weeks before my next fishing trip, I usually reapply a thin coat of line treatment to the last thirty or so feet of the fly line.

Certainly Silk Fly Lines require more care than current synthetic fly lines.  But Silk Fly Line exhibits its own unique properties that many (including me) prefer. And, at least to my ears, the Silk Fly Line “sings” when I cast it.