I am looking to build a permanent enclosure for my beardie and had some questions. I have access to some free wood etc. and I knew certain types were not good for them. Is there a way to seal pine or other wood's so that they are safe to use or what wood's are acceptable?
I'd go with a hardwood if you can find it. Melamine board is also a popular cheaper option. You want to ensure the wood hasn't been treated with chemicals for outdoor use. Other than that, I'd just seal it up with a few coats of polyurethane (and give it plenty of time to dry and air out before use).
The polyurethane may prevent a problem but I'm not certain if it's worth the risk if other wood is available. There isn't a whole lot of evidence to prove or disprove the harmful effects of pine the way there is with cedar (don't use cedar at all). More info about it here http://www.anapsid.org/cedar2.html