how to avoid lump formation due to carbonates in lab slab cultured marble samples.?

when we make lab samples, small lumps are formed which is difficult to break in the mixtures. This on pressing gives spots of carbonate specks which looks very odd and damages the beauty of the samples.

Gorfram7 years ago
I'm guessing this refers the the same cultured marble casting process you refer to in your previous Question. The carbonates are presumably from the calcium carbonate in the marble dust, and it sounds as if they may being absorbed into solution in the epoxy matrix (or perhaps separately into to resin or the catalyst?). and then precipitating out at some further point in the solidificaction process. Perhaps the carbonate is highly soluble in one of the liquid components, but much less soluble in the solidified resin?
lemonie7 years ago
We need to know a bit more about what you are making and how if we are to help. But I should think you know more about this than we do? L
Kiteman7 years ago
If you give a brief outline of the process, we could help more.