Dacron or Fast Flight?

[McDave]

I've been buying ready made strings for the past few years, but I recently had a desire to make a bowstring again.  Neatly packed away in my bowstring material box are 4-5 partially used rolls of bowstring, all unlabeled.  I'm sure it was obvious to me when I packed them away which ones were dacron and which ones were fast flight, but not now.  Is there any way to tell dacron from fast flight string?

[Three Arrows]

dacron came in spools with black inside.  Fast flight had red inside.  Look at the center of the spool.

[McDave]

Thanks!  Never noticed that.  You saved me some spools of bowstring.

[Blackhawk7204]

Fast flight strands are also much harder to cut with scissors. Dacron will cut easily.

[Tree man]

Fastflight is lighter(less dense per volume) than water. Dacron is heavier. Thus a float test can tell you something with rope...but the wax on string strands may make it tough to tell. Dacron melts at a higher temp, burns while in a flame and forms a black glob that can be stretched into a fine filament while still soft(it hardens when cool). Fastflight shrinks curls and burns but cannot be stretched into a fine filament.
Dacron smells oily and sweet when burning. Fastflight smells like parrafin wax. The FF melted glob is a waxy soft residue-Dacron's glob will be solid.

[McDave]

Thanks Justin, this will give me another way to verify which is which.  I had a hazy memory of which string was on which spool based on the colors, but wasn't sure, and Three Arrows method confirmed what I had been thinking, as there was a red insert in the spools that I thought were probably fast flight, and not in the others.