2-part resin more flexible than the Alumilite ?

--Try Tap Plastics; they're a chain of stores on the Left Coast. You might be able to find what you're looking for there; they've got a good selection of molding resins and similar stuff.

You can get castable polyurethane resins in very high hardness, like rollerblade wheels for example. Just make sure you get a high-strength resin, not a mold-making resin, and take care to ensure that it's low viscosity before cure. You'll need a vacuum chamber to de-air during casting.

More resins are available if you can handle a UV or thermo cure instead of RTV (room temp) - these are more common in commercial apps.

Clifford Heath.

Thanks! Rollerblade wheels are about the right hardness I need ... any idea what shore rating that is (ballpark estimate) ? Thanks again! JCD

I believe they're 90 or 95 duro. Just be careful with hardness figures, as some molding resins are very hard but have a very low strength, meaning they crack and abrade far easily.