AS I EXPLAINED IN AN EARLIER POST the act of Pumicing is the using of pumice and alcohol to fill the pores in woods like walnut and koa. The good news is that it is never too late to pumice. I had thought that the pores were all filled on this koa back but after letting it sit all night, and then looking with a 10 power glass I realized that some of the pores were still a bit open. Even though I had applied the first coating of french polish and the back was shining nicely, I again took pumice to it and was able to completely fill those pores. At any stage of the french polish process you can go back to using pumice. The pictures show the pumiced portion towards the rear of the uke, and the still un-pumiced area towards the neck. Let it dry for a few hours and go back at it with normal applications of dilute shellac and it immediately shines again, only better.