>While starting the port flap lay-up, I had the impression that my epoxy
>pump did not deliver the right amount of hardener. Checking things out
>with a precise scale confirmed my impression. While trying to adjust the
>pump it stopped to deliver hardener at all.
>
>Here is what brought me into a constant state of panic: If the pump did
>not deliver enough hardener for me to recognize the mismatch, how long
>did it deliver hardener in a mismatch to the resin to impair the
>resulting epoxy?
>
>How can I tell if the epoxy I've used yesterday (and the days before)
>are O.K. ???
>
>
>Norbert
>#271
Without going to the complications of chemical analysis you could carry out
a scratch test. If you scratch the surface with a sharp object you should
scrape off a white dry swarf. If the epoxy has not cured properly it will
scrape off a gummy substance (not to be confused with the stickiness often
found on the surface of a cured laminate).
If you are still concerned, let us have a sample which can be sent for
analysis. There are two types of test which can be made. A DSC test which
would require at least 50 micrograms of scrapings, or a DMTA test which
needs a piece to be about 3-4 cm long x 1 cm wide. There would be a charge
for this testing.
Regards
Andy
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