I have not had problems with bad batches of epoxy due to uncalibrated pumps, but I rarely trust them. The pumps are not much different than the ketsup pumps used at your local hot dog stand and there is no reason to believe anyone did additional engineering to make them more accurate than neccessary to dispense a little mustard.

They still seem to work reasonably well, but it is good practice to pump into a calibrated cup. If the pumps start "burping", definitely pump into a calibrated cup. The pumps are still easier to use than trying to pour, so even if they are not 100% accurate, they are worth while.

> While pumping a lot of epoxy this past weekend I made a very interesting
> and somewhat disturbing discovery. My pump was not pumping out consistant
> amounts of epoxy!

> I was wetting out my hull and when coming to the more finiky areas I was
> pumping into a syringe to measure out half batches. That is when I
> discovered my pump would sometimes give me 27,25 and 23 ml's!!! The epoxy
> is a 2:1 ratio mixture and I have never had problems with the epoxy fully
> curing. I therefore suspect that I'm within the tolerance of the epoxy
> even though I'm getting these wildly varying amounts. I was very suprised
> because I had understood that these pumps were supposed to be very
> accurate.

> Has anyone else encountered this phenomenon?