I have read in last days in a french forum that some of them are trying a different way to recycle old (and new cheap) fly lines. The modern fly lines have a lot of advantages compared to old silk lines, but they are more rigid, they have "memory" and are thicker that natural lines.
Well some french fisherman removed the plastic surface from modern fly lines putting them 24 hours in ...sorry I didn't found the translation. In italian is called "acetone" (dimetilchetone, propanone e beta-chetopropano): it's a solvent used by women to remove nail warnish. Very easy to find.

It removes the "hard" surface from the lines. Then they grease what remains of the line usually with red mucilin, or before the mucilin treat them with oil like silk fly lines.

I'm waiting for tomorrow to buy "industrial" 100% acetone (the one of my mate and my daughter doesn't seem 100%) and try it.

In the same forum some of them are trying even to make level fly lines using dyneema or dacron lines treated as silk lines.
For who knows french:
http://www.moucheur.com/soien.html
http://peche-mouche-seche.xooit.fr/t160 ... urelle.htm
http://www.mouche-fr.com/forum/impregna ... 22927.html

@pearow
I'm trying to do it now, it's the first time that I try it. How do you remove the outer part? How many time you leave the line inside acetone? Then do you use something (a cutter or so) to remove it?
I left the line about 24 hours in acetone, but it lost only the color and remained "hard". The outer part is still there.

I put it in and count to 60; remove it and dry off the acetone with a paper towel, then use my thumbnail to remove the outer layer; never had a problem using this method-p-

Its not; they have different core for different applications as I understand it. Some tropical lines have a mono core if I remember correctly(I'm far from being a fly line expert!!)-p-