DryLok would give you a gritty texture. The oatmeal adds the appearance of corrosion/rust patches. If you mix it so that the consistancy is on the thick side (think thick soup) the oatmeal will adhere nicely and not slide off. The sand also acts as a binding agent. I did mine outside on a sunny day and it was dry within under an hour. You'll get some drippage so put a tarp or something under it.There are a couple pics of my cauldron in here. Used a half/half mixture of elmers glue and water, then added oatmeal and sand. Slathered it on, heavier in some spots. Let it dry thoroughly. Hit it with flat black spray paint then a couple different shades of watered down brown acrylics. Came out pretty well
That does look good. The post I read online said the oatmeal kept sliding off. I thought maybe the Drylok would give that rough texture like sand and then I could spread on the oatmeal and glue mixture. Your idea sounds easier though. I will give it a try.
This turned out awesome!!! I love this lookI use drywall spackle to create texture and then an oxidizing paint to create a real rust effect. I've attached a couple of photos; you can see the original post and additional photos at: http://www.halloweenforum.com/halloween-props/147907-bubbling-cauldron-skull-base-2-0-a.html