Waterproofing cardboard

[bryn]

at the grocery store all the boxs they use to ship fruit or veggies are allready waxed they hold up well when wet. just ask to look through their dumpster

[johnsn]

Use master series MasterSeriesCT Coating Line Rust Prevention - MasterSeriesCT it will work on card board.
john

[gascort]

Didn't you just have a primary election there too? contact the losers and ask for their signs.

[azraelswrd]

In November there's going to be a lot of losers so an excellent time to farm for plastic signage.

[jtmax24]

My experience with waterproofing cardboard.

In one instance I have duct taped a cardboard table than painted over it with acrylic paint bought at the local hobby store, worked fairly well and did moderately well when water or grease was spilled on it.

My next cardboard table I bought some outdoor craft paint and primer paint and just paint the cardboard paint. This method worked best for me.

The worst is using the cheap paint or cheap duct tape.

Buy "Duck Tape" brand and any good quality paint.

[evolutionmovement]

How about fabric and aircraft dope?

[Rokeby]

First post, been lurking for 18 months.

Drive '08 Prius... and love what you all are up to 24/7.

The "original" high VOC contact cement is an excellent cardboard water
proofer. Apply with a roller, you can see it penetrate the surface as it turns
dark brown. Let dry overnight to a non-tack surface... can be painted w/oil
base paints. (Don't forget to plug up the corrugations to prevent water entry.)

Shhh... this is the "secret ingredient" to many successful cardboard boats.

If you're especially clever, motivated, or desperate, apply a skin of
"Contact" brand pre-glued, plasticized surface shelf paper. Hard to get
perfectly smooth, but many colors & patterns... wood grain? ...paisley
anyone?

Hope this helps

[aussie_modder]

Definitely agree with the aircraft dope idea. Either apply it directly to the cardboard, or add a layer of brown paper (either as one big sheet or cut into 6' strips etc) which may disguise any writing.

Brown paper over polystyrene foam is also good (using water based glue 50:50 with water), finished with dope and then painted works well (or leave naturale), and is nice and water proof. just be sure that the dope isnt applied too thick or it will seep through the brown paper and dissolve the foam.

When i get to it, my front air dam will be made this way..... theres always plenty of packing foam to be had. keep your eyes peeled for EPP foam (model aircraft industry term), which basically springs back when you push on it. very handy for those light impact areas (ie lowest to the ground). i've seen it used for packing office supplies.

[Bicycle Bob]

The official waterproof cardboard from the veggie boxes is soaked in paraffin - candle wax. Since the veggie boxes are usually ventilated and drained, you might want to just pour wax through other cardboard. That should be the cheapest and easiest really effective treatment, if you don't start a fire.

[moorecomp]

Bicycle Bob has probably already seen this:

Building Composite Structures with Cardboard

Another good material is formica. Check around, you should be able to find scraps from a counter shop somewhere.