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I too have encountered inconsistencies with my epoxy pump. This is
evident by the variation in color of the epoxy mixture which has
typically erred on the too dark (too much hardener) side. I had once
thought that this may be due to the changing color of the 2 parts (the
hardener seems to darken) as it ages somewhat (good for wine, but not
for structural glues, huh?). I have yet to realize a soft or uncured
batch. I have also observed that the larger batches appear to be more
consistent and figured it was the result of "statistical averaging",
e.g., the first stroke too much hardener dispensed, the second stroke
too little, and the next 5 or so fairly correct with the final, total
batch being about right. For small batches I always use my scale (don't
want that inaccurate first pump stroke to make up 50% of my total
volume) and try to select the final weight (volume needed), and thus
each part's weight to mitigate any round-off and/or resolution
inaccuracies of the scale and my calculations. I have found my weighed
batches, especially the larger ones, to be very consistent, as they
always seem to start setting up (flashing) at about 20 minutes in the
hot summers of southern Louisiana. Of course I use a stop watch to keep
close tabs on how much time I have left. I recall reading once that a
qualitative test is to scratch the surface of the unused, "cured" epoxy
mixture with a sharp knife - the epoxy should feel hard and yield a nice
"crisp", "white" and shallow scratch line.
As a side note, I am a new subscriber to LML and the "volumes" have been
a great source of info and have served to "pump me up". The monthly
periodicals I subscribe to help, but the almost daily "posts" have a
more immediate impact. Keep up the great work, Marv, and forgive me if
I messed up the "format" with my first submittal!
Dana Westphal
360 MKII (finishing horizontal stab)
Dana L. Westphal
Reservoir Engineering
dwes@oceanenergy.com
[Your post looks great, Dana, no problems at all. Looking forward to
seeing many more in the future from you. Thanks, <Marv> ]
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