Yes, I actually do that with a big orbital sander. It works quite well but my last casting still had some small bubbles even after vibrating for about 3 minutes. I'm wondering if vibrating the mixing bucket before pouring the cement into the mold would do any good. I have enough panels done now to reroof the south wing. I have been working on too many things lately and haven't had the time or energy to post what I have accomplished. I'll try to get something posted soon.
Winn Erdman Steamaholic 291