wrote in message
...
Hello,

I have a design made out of cardboard that I will be keeping outside
in the elements. I need it to be able to hold rain water inside it,
so I'm wondering if there is any way to water proof it? Here are some
ideas:

1) What If I painted it with an oil based paint?
2) How about using epoxy glue and covering the entire inside?
3) What about coating the inside with Portland Cement?
4) I could coat the inside with tin foil, then use epoxy on the
joints?

Is there a much better idea than these?

Thanks


Fiberglass it.