I've also been learning to make birdhouses from a form of paper mache. But not the traditional kind. This is shredded newspaper that's then boiled for about an hour. After it's drained well and cooled I add a mixture of flour, glue, salt and linseed oil.
I'm making them over empty milk cartons (recycling). Once completed, they get 3-4 coats of linseed oil, then are painted and sealed.
Supposedly, they hold up quite well for several years outside. I have my first one hanging outside now as a test. It's rained a couple times. I've checked each time and there's been no noticeable damage or problems of any sort.
I'm adding doors in the back (or in some cases a hinged top) for clean out, as well as drainage and air holes.
So far I enjoy working with this paper pulp. I'm calling it "paper musha" since it's really pretty "mushy" LOL.
Here are pictures of three, in various stages of completion.
