Filling the Gaps

I could not do much on Sunday as I had to fill the gaps left over from re-glassing the oil cooler mounting plate. It's not technically necessary but the side exposed to the cooling duct will be visible and I also would like to be able to clean out any crud that might build up over time.
I used SuperFil which I had bought from Aircraft Spruce a while back to eventually use this stuff on filling the holes in the pull rivets - at least the ones on the sides and the surfaces facing up (and therefore can hold water and lead to the stem part to rust). I had no experience with SuperFil and the can doesn't say anything about curing time, pot life or any such things. All it told me was how to mix the stuff and that was it.
It turned out that it took a full 24 hours for the stuff to cure. And I won't get to sand it for another 24 hours.

This picture shows the application right after I was finished smoothening it out. The texture is a bit dry and therefore it's not easy to get it evenly applied. It settles after half an hour and develops a nice, almost wet surface that hardens out like that.
The next picture shows it after 30 hours of curing.

The next step is now to roughen up the shiny surface of this blue stuff and then - hopefully - apply the last coat of it to make the cooling duct smooth and paintable. Then it will get aligned with the radiator and then installed to the lower cowl.