finishing out a RSMH

So after researching most of last Winter, collecting materials in the Spring, this Summer I've spent building a nice sized rocket stove. I'm getting almost to my finish layer of cob all the way around. How do you get your finish? I was thinking of in the last inch or so mixing a clay, sand, portland cob to smooth things out and not worry about straw pokies sticking out of the mix. Oh and has anyone done anything with colors? And if any Washingtonians are going to the NE Washington Fair my place is about 15 miles North of Colville and I invite ya to come up and show me what I did wrong. I've fired the thing and it draws fine, just finishing the cob work is all. Suggestions and pointers would be welcomed though. Peace, Clark

Hi Clark; I just put a color layer on my rmh, I used store bought (home depot ) concrete coloring, a mix of red and black to get a brick color. On the final layer of cob i was using fireclay and sand in a 50/50 mix with no straw. Include pictures of your rmh if you can .