Plaster finish

Hi, I just put my layer of plaster on, and I think that I have not added enough manure to the first batch. It looks kinda sandy compared to the second one, which had twice as much manure. I am wondering if there is something that I can apply that would make it stronger...ie lime wash, etc.

if anyone has had any experience with troubleshooting the plaster layer, I would greatly appreciate any input. By the way the porportions i used for the sandy layer was 1 part sand, a half part clay, half part horse manure, 4 cups wheat paste.

Just to clarify,l I purchased two of Erica and Ernie's dvds on rocket mass heaters, purchased plans, bought Ianto's book. But I am still a little confused over the instructions on the plaster and finishing. I was hoping someone had some troubleshooting points in this area....