I've been using Amazing Casting resin to cast very small parts for model trains. The molds can have 20 or more cavities each. The resin does a very good job of capturing the minute detail, but because it cures so quickly, I can't pour the resin into very many cavities before it starts to cure. I can quickly overfill the molds and sort of squeegee the excess off into another mold, but even so, it starts to cure and becomes to thick to even fill the cavity, let alone get all the detail. You can see in the attached photos the number and size of the cavities in the molds and the intricate details in the castings.
Would slow set 7 work for this kind of casting? Is its viscosity low enough to fill the mold completely before it starts to cure? The main issue is that I can only use maybe 1/2 oz of resin to fill the molds before it starts to cure. I need to mix at least an ounce or so to insure that I have the right amounts of resin and hardener to cure properly, and that small amount is pretty difficult to get right.
I think it would, any of the longer open time resins will be the best to use on that many cavities. There's also the Slow Set 15 which has a 15 minute open time - for me personally, I'd try the 15 first but the Alumilite page for it seems to be down at the moment. Have you tried timing how many you can fill before it cures too much to use? I use the stopwatch function on my watch every time I use any of the resins and mold materials so I know I can fill about 3 or 4 small cavities with RC-3 before it hardens up. For molds of that size (thank you for including a ruler) I'd say the 7 should work for the most part but be sure to be very fast. Let us know how it works for you.