What can I use to make a plywood stand waterproof?

[jescereal]

I can't find a straight answer on this. I'm putting a sheet of plywood over the petco Brooklyn stand to evenly distribute my 29g tanks weight. But I want to make sure the wood will be waterproof.

Most importantly, I'm not looking for a high class finish. I just want to paint it with something cheap that'll make it waterproof.

Any links to brands and recomendations? I've been researching for hours and I still don't have a clue. Someone's response is then contradicted somewhere else.

 

[Leeatl]

I have built a couple of canopies and stands for tanks and all I have used is exterior latex paint . Two or three coats . I have used white for the inside of canopies and whatever color for the outside of canopies and stands . The inside of stands I don't worry about cause there should not be that much if any water there...lol but if you want can paint with same paint . I have canopies that are 5 years plus old and still look like new . I just use the cheapest Home Depot paint . I do have one canopy that I stained the outside and painted the inside white . Many combinations , only limit is your imagination . Oh , I paint the inside white to reflect light...lol

 

[Brookster123]

Thomson's water sealer.

 

[goatnad]

I second using something like thompsons water seal.