That is one web site that's been around for a long time. It's also a prime example of the different molds you can find right under your nose. Do you know what was used to make the top of the birdhouses? For some reason, the site calls them birdfeeders not birdhouses. Come on, take a guess? Billie

you really don't need to purchase a book or take a class, you can find answers to any questions you have right here, if you search, or you can just start reading the posts from way back and learn a whole bunch. i learned all about crete and tufa right here a couple of years ago.there is gobs of info on this forum, a lot of the older posters are gone but the posts are still here.