Hey guys I'm new to the military diorama scene but ,so far I am truly enjoying myself, even correcting my mistakes. What I wanted to know since I am putting or, starting to put a floor on top of my base depending on the answers I get in the forum, can plaster go directly of plywood? Or would the moisture be such an issue that a sealant should be laid down? If so what kind od sealant would do the job. Right now I have a clear semi-gloss varnish in the workshop that I hope will do the trick if neccessary.

Any advice would be appreciated. But I just found a recipe posted by USMarine. I do not have any sand so I may have to wait till tomorrow to continue my project.

Best bet is to seal the plywood with a good varnish first. This will prevent warping of the wood as the moisture from the plaster is absorbed by the plywood.

I also like to use my staple gun to put some staples in the board. That way when you lay on the plaster it will go under the staples and form a mechanical bond with the board. Don't apply too much pressure to the staple gun as you want the staples to sit a little proud.

I like to drill shallow holes as well to give the plaster something to grab. Whenever possible, like hills and mounds, I glue small pieces of wood to give some more grab to the plaster.

Thanks for the advice guys. I also thought after taking a break and doing some brainstorming that some old window screen that I have in my wash room may come in handy too. I think I will cut it to size and either staple or use a hot glue gun to lay it down.