Re: Epoxy-Granite machine bases (was Polymer concrete frame?)
Got to be careful with percentages.
9% weight of aggregate - what does that mean?
1000grams of aggregate, plus 90 grams of epoxy added? (=8.26% epoxy content be weight in final part)
910grams of aggregate plus 90grams of epoxy?
Volume is different again....
Re: the water void check. If your aggregate volume appeared to change then it was not properly compacted and the results are suspect.
I think you are better off with a container of fixed size (e.g. a big jar). Measure volume of container fill with water then pour that into a measuring cup). Fill dry container with aggregate mix. Vibrate or tamp (compress) aggregate. Make sure completely full. Then add water from a known volume. Wait as it may take time to wet out. Vibrate or tamp. Add more water as needed. Amount of water able to be added = void volume (well a less viscous fluid might be even better at true void content).
Void content / volume just tells you the maximum amount of epoxy you can add before you start wasting epoxy or separating the aggregate. It does not tell you the minimum epoxy content.
7xCNC.com - CNC info for the minilathe (7x10, 7x12, 7x14, 7x16)