Hi! This is Jon on behalf of Expert Village. In this video clip, we will be applying our second coat of finish. Once the coat of polyurethane has dried for about 24 hours, we can just feel that and make sure there is no sticky or tacky areas. The next thing we need to do is take a worn out piee of sandpaper. Here I have an old sanding disk that is pretty worn down and we need to lightly sand over our entire project. Now this is going to smooth down any rough areas that polyurethane might have left. Once you've lightly sanded your piece, you should be able to run your hand over it and get this kind of light white film on your fingers. Now that is what you want to look for when you are sanding. You don't want to sand too much that you go through that new coat of polyurethane just until this kind of powdery white substance appears. Once that is all sanded down and it is nice and smooth, we are going to take our foam brush and we are going to apply that second coat of polyurethane. Now you are going to want this one to dry for 24 hours also and if after 24 hours it is still a little bit rough, you can always add a third coat and if you really want to, you can add a fourth coat. The more coats you add theoretically the more smooth it is going to be and the more protected it is going to be. But between coats you are going to want to make sure that you sand real lightly. Now when I installed these bookshelves, I bolted the bookshelves together first with a couple of wood screws just to pull them tight and then I screwed it into the studs in the wall and this is going to secure them just so they don't fall over.