Over the past few months I have used a lot of epoxy (primarily filling flaws in mesquite lumber). In fact a quart of System 3 Resin with a pint of System 3 medium speed hardener, mixed a fraction of an ounce at a time. It is rather fluid, which is great for soaking into cracks, and by the next day it is ready to sand or process (or add another layer if the crack was deeper and the soaking slow). Mixing involved 44% as much hardener as resin, by weight.
General discussion of epoxy, that I have seen over the years, suggest that some brands or types have a more flexible formulation - use more hardener to harden faster, use less to harden slower. If I have a deep crack, I am delighted to allow time for it to flow, but if I am just filling a small flaw on the surface, I would like to harden faster so I can get on with the process, not wait until tomorrow. No hint of that flexibility with the System 3. Am I not remembering right (at my age that happens too often), or are there other brands of epoxy, that are more flexible in cure speed, that I should consider?