Hi matrix1829,
I seal the whole cage inside and outside first with the Minwax Helmsman Spar Urethane
3 to 4 coats of this. Then after it has dried I coat the inside bottom of the cage with
envirotex. (The clear, high build epoxy finish)
If you do use the envirotex e-mail me and I can give you some tips on using it.
Or if you want to I can e-mail you my phone number and we can talk over the phone.
If you change your mind on make the cage your self I could always make it for you.
Take care,
Tom