your wax cord is probably too small.  Size of wicking is a
careful match between melting point of the wax, size of wicking,
and diameter of candle.  Melting point can be affected by the ad
addition of an acid, but assume you do the same every time.
 
If the flame melts wax at too great of a distance compared to its
the wicking ability, the wax flows in and extenguishes the flame.
 
If the heat doesnt melt wax far enough out, the wick pulls the available
wax up, burns it, and melts the wax underneath the flame, creating
a hole burned down through the middle.  Oxygen has to be able
to get down to the flame so this helps self-regulate the size,
and thus the burning speed, of the flame.
 
You are really dealing with a self regulating feedback loop.
AT&T should have lots of engineers who could help model this but
you can also visit a hobby shop and get a candle makeing guide
that talks about wicking sizes for parafin candles.  Beeswax
melts at a higher temperture so you could use slightly larger
wicks than reccommended but it is generally not necessary.
Basically, the bigger the candle diameter, the bigger the wick.
 
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+    Raymond J. Lackey                                     +
+    Beekeeper 10 years with 25 colonies on Long Island, NY+
+    INTERNET: [log in to unmask]                       +
+    Mail: 1260 Walnut Avenue, Bohemia NY 11617            +
+    Home Phone: 516-567-1936  FAX: 516-262-8053           +
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