Weatherproofing Corrugated Cardboard

I'd probably try some Kamp Dry. Sporting goods or camping stores will have. Might be tough to wet down corrugation's. Maybe if exposed you could put hot melt adhesive on seams.

Frank

Art Todesco spake thus:

I did exactly the same thing a few years ago. Made a really kewl flying saucer out of cardboard, complete with flashing lights, and put it outside with a couple of "aliens".

Then the rains came and ruined it. Became one soggy mass of painted cardboard, slumped over the bushes. Very sad.

No, there's no practical way to prevent this. Use something else or don't put it outside. (You *could* cover it in many coats of epoxy paint or fiberglass, but then you would no longer be working with just cardboard.) Sorry.

You can try varnish or several other products that will slow down the process, but it still will get in the edges and that will be the end of it.

Maybe get some ideas from here:

Could you wrap them in something like extra wide Saran Wrap?

Jeff

Have you tried Thompson's Water Seal?

There is a plastic version - formed like corrugated, but all plastic. I would check craft stores for a more suitable surface. There is also a painting ground, for oil or acryllic, made like masonite but with a "primer" on it. Probably would only have to waterproof the edge, if anything. I can't imagine anything that would reliably coat the inside and outside of corrugated cardboard.

It's pretty easy to do with canning wax and a big paint brush. Melt the wax in a double-boiler and brush it onto the cardboard slowly so it soaks in while it's still molten. (The thermal mass of wax in the brush will keep it hot longer -- if you brush too fast, it will solidify before it penetrates.) Take extra care on the edges to make sure it soaks into the center corrugation as well as the outer layers. Then make a second, faster pass over the edges that will block the passageways so water can run inside.

For larger projects, good outdoor-fabrics stores will have 5-gallon cans of wax in solvent that's used for waterproofing canvas.

Commercially, corrugated is wax dipped for waterproofing for the seafood industry. Your idea should work well.

Joshua Putnam spake thus:

Of all this suggestions given, this is the only one that has even a

I guess the only sure way to do this would be to use some kind of plastic (someone suggested the cardboard-like corrugated stuff).

Instead of using cardboard, use coroplast. Same construction as cardboard but made of vinyl instead of paper. Getting paint to stick may be another issue though. Art supply shops & framing places might have it.

DAGS for coroplast.

I have unloaded many a Corrugated Cardboard box of vegetables that were soaking wet and covered with ice. It will hold up if done correctly. No doubts