Weatherproof Paper Cement Clay for Outdoor Sculptures

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Play Video about Weatherproof paper mache clay recipe for outdoor sculptures

I’ve been experimenting with two new recipes for weatherproof paper mache clay.

Note: We had a vote, and we’re now calling this new recipe “Paper Cement Clay.” 🙂

I should have done these experiments way back in 2013, because that’s when Warren Eggleton wrote a guest post for this website. He showed us how he made his giant pots using a version of our paper mache clay recipe, with the addition of Portland cement.

The last time we heard from him, his pots had been outside for six years, in Australia.

  • I recently made a casting of a leaf with this mixture.
  • And I sculpted a garden toad to go on the leaf. The new sculptures will be left in my garden over the winter, to see how well they hold up
  • And there’s now a recent update on the toad. You can see it here.

I made some changes to Warren’s version of weatherproof paper mache, just to make sure every batch comes out exactly the same.

I also created two different recipes. One of them contains all the usual ingredients for paper mache clay, but the flour is replaced with Portland cement.

The second recipe leaves out the drywall joint compound, because it’s hard for some people to find.

I tested both of my new recipes by spreading small samples onto cardboard every 30 minutes, to see how long we could continue to use them before they stiffened up too much.

The mixtures will eventually get hard in the bowl because of the Portland cement, but I was able to continue using them for at least 3 hours, with the room temperature at 76° F (24.4 C).

Warren told us in his post that it will get stiff faster in warmer weather.

Test pieces for weatherproof paper mache clay recipe with drywall joint compound.

Test pieces for weatherproof paper mache clay recipe with drywall joint compound.

Test pieces for weatherproof paper mache clay recipe without drywall joint compound.

Test pieces for weatherproof paper mache clay recipe without drywall joint compound.

How the two recipes are different after they dry:

Difference in texture with paper mache clay for outdoor sculptures

The texture of the recipe that includes the drywall joint compound is smoother – you can see that in the test piece on the right in the image above. However, for an outdoor sculpture, the difference may be so small that it really doesn’t matter.

Try the recipe that you think you’d prefer, and put your sculpture out in the garden.

After it’s been out there for a few months or a year, please come back and let us know if the rain, snow or sun has caused any noticeable damage.

Weatherproof paper mache clay recipe with drywall joint compound:

Note – be sure to watch the video at the top of the page to see how the ingredients were measured and mixed. If you want to make a larger batch, you may want to mix it with a paint mixer attachment on an electric drill.

Mix together:

  • 1/2 cup drywall joint compound
  • 1/2 cup Elmer’s Glue-All (PVA glue)
  • 1/2 cup damp toilet paper or recycled paper*

Mix until there are no lumps of paper in the mixture. Then add and mix well:

  • 1 cup Portland cement.

*To see how to weigh the damp paper, watch the video on this page, starting at the 3:06 mark. You’ll need to scroll down the page to find the video. If you don’t have a kitchen scale, soak the paper in hot water, then squeeze out most of the water (but not all of it) and use 1/2 cup of the damp paper.

Weatherproof paper mache clay recipe without drywall joint compound:

Mix together:

  • 1/2 cup Elmer’s Glue-All (PVA glue)
  • 1/2 cup damp toilet paper or recycled paper*

Mix until there are no lumps of paper in the mixture. Then add and mix well:

  • 2/3 cup Portland cement.

More experiments needed!

Warren had great luck with his pots outdoors in Australia. But I can’t know if these recipes will work here in Minnesota until I make a sculpture and leave it outside to see how well it does in our crazy weather.

In fact, we all need to consider these experimental recipes until we’ve had a chance to try them ourselves, in our own climate.

If you experiment with one or both of the recipes, please come back after a few months and let us know how they worked! 🙂

74 thoughts on “Weatherproof Paper Cement Clay for Outdoor Sculptures”

    • I used the only kind available at my local Lowes store. It’s called Type I/II. I also ordered some white Portland cement to play with, and it should work, but I haven’t had a chance to try it yet. Have fun!

      Reply
  1. I’ve been following you for years, and it’s always a pleasure to see you try new things, while you create great art. I’ve had great success with taking your Wood Glue based one, with adding a few things to base. Your older recipes have been successfully waterproofed and are still fine years later, when I used several coats of clear rubber spray. But last year, I needed shine to my life-sized Demodog, so I used Marine Polyurethane.
    It worked perfect and the piece held up well for the few months of Halloween. Thanks again for sharing your expertise.

    Reply
  2. Hello!
    thank you for the recipe!

    I have 2 questions, first one is would this recipe glue to a piece of wood afterwards or in other type pf paper clay? and also what type of sealer do you use? thank you!

    Reply
  3. Well im about to try my first paper mache sculpture with your recipe. ( the indoor, until i saw this out door one…ugg so many choices.) I need all the luck i can get. Lol
    Thanks
    Billie
    Welland Ontario Canada

    Reply
    • Good luck! And remember that this recipe is still experimental – it hasn’t yet been tested in winter weather. Be sure to come back and let us know if it survived your Ontario winter.

      Of course, you can also use this recipe for indoor sculptures, in case you needed one more option. 🙂

      Reply
  4. Hello! I’m trying to create a large pumpkin topiary for my front porch. I’ve experimented with plaster strips, but a lot will be required to cover 3 beach balls (24”, 12”, 9”). We also painted a thin layer of plaster over the first mache layer, but it took away from the pumpkin indentations made using twine.

    Do you have any suggestions? I wondered about using plaster and an old sheet?

    Your page is wonderful – thank you!

    Reply
    • Hi Leslie. You might like Dan Reeder’s cloth mache. It would go a lot faster. He dips torn strips of an old sheet in a mixture of white glue and water, and puts it on over his dragons. It should work over a pumpkin topiary, too (great idea, by the way!). You might need to put it on in several sittings, because gravity could try to pull it off.

      Reply
  5. Jonni,

    I have my 7+ foot tall Giraffe, head, body and legs, very close to putting your Paper CEMENT Recipe over it. I have several questions that I just want to go over with you…..please….

    1. According to what I have read on your website, I should first do a thin layer of Paper Cement on the Giraffe, followed by a thicker coat after the first coat has dried thoroughly.
    2. Should I wet down the first coat of Paper Cement a little bit at a time as I add the second layer? Or should I just add the second layer right over the dry first layer?
    3. Do you still believe that the two recipes for your Paper Cement (one with Joint Compound, and one with out) seem to spread the same, but the one with Joint Compound seems a bit smoother after it drys?
    4. Have you noticed any difference in the drying times, cracking, etc with either of the two recipes? Anything?

    I have been working non-stop on this project, and I don’t want to mess it up! Grin If you have more suggestions, let me know…..

    Thank you!!!!!!!!!!!!!!!!!

    Janice in northern Minnesota, near the Canadian border

    Reply
    • Janice, we’re in luck, because Anthony just posted a photo of his witches and cauldron. This is his second project with the paper cement clay. so he has a lot more experience with it than I do. I only made the tiny test pieces with both versions, and my toad is only testing the version with the joint compound and the specific sealer that I used. I did add water to my first layer after it dried, because that’s what you would do if it was concrete, but I don’t know if you really need to. I’d suggest leaving a comment on Anthony’s post, and hope that he responds. He’s our current “expert,” I think.

      Reply
  6. Can you sand the cured product? I seem to have a hard time getting it as smooth as I would like. The more I touch it the worse it gets. I have to walk away. Can I sand out a few bumps here and there once it’s cured?

    Reply
  7. I am just super excited to try this new recipe out!

    I really like the recipe version that uses weight as a measurement, so I don’t spend all day scraping my dedicated measuring cups. I’ll be sure to measure this recipe to get those weights, however I am in a humid climate and it may effect the outcome for those in a dryer climate. would you like me to comment my findings?

    Reply
    • Yes please! Even if your weights don’t work perfectly in all environments, it would give us a starting point. Then we could all tweak your recipe to fit our own needs. Have fun with it! (And remember – it’s still experimental, so we don’t know how long sculptures made with it will last outside. 🙂 )

      Reply
  8. Jonni, I was wondering if the longer the cement clay rests does the consistency become more like a modeling clay? Used for covering our armatures or molding?

    Reply
    • It does start to get stiffer after an hour or so, and hardens between three and five hours, depending on the temperature. I wouldn’t want to use it as a solid sculpture, the way you’d use concrete, because it might take too long to dry all the way through, and it might crack. I haven’t tried it, though. Is that what you meant by ‘modeling clay?’

      Reply
  9. Jonni, your articles and videos are such a huge help! I am interested in making some hanging jack-o-lanterns and am considering this recipe (and the bag of rice method in Rex Winn’s guest post) so they will hold up during the Halloween season. But with the concrete in the mix, will it still be possible to cut a panel to remove the bag of rice (or to cut shapes from the pumpkin to create the jack-o-lantern face)? I just want to make sure it won’t make the figure so stiff/hard that I can’t cut into it. Thank you!

    Reply
    • Hi Kristina. I haven’t tried doing that, so I can’t say if it’s possible to cut the dried paper cement or not. The original paper mache clay dries really hard, too, so if I was doing it I would make some kind of ‘dam’ to create the hole while adding the material. Maybe tape a strip of plastic around the bottom, rub some oil on both sides, and add the material to the pumpkin. Then when everything is dry, you could pull the two pieces apart.
      Do remember, though, that this recipe is still experimental! That’s especially true if water could get inside your pumpkins and stay there for a long period of time. And cement is not waterproof, so be sure to seal them. Watch them carefully, and if they get rained on and then start to feel soft, bring them back inside to dry off. I’m hoping that we get lots of experiments going, but remember that we don’t know how well the material will hold up yet, until we all try it to find out. My toad has not been through three rainstorms, and he’s still doing fine. But it hasn’t had a chance to freeze yet.

      Reply
  10. I love your work and I watch most of your shows. I wanted to ask you if you have ever tried Engine Enamel, its of course it’s for car engines but they said it sealed the medal, like it might make your work waterproof in a spray. I am sort of house bound, so I can’t try it, or I sure would. I work every day with the clay, love it.

    Reply
    • Hi Bev. I haven’t tried engine enamel. In fact, this is the first time I’ve heard of it. But I did use Rustoleum Matte Clear Enamel on my toad. I’ve never used it before, but the ad for it was convincing, and now we’ll find out how well it holds up outside. I’m working on that video now, and it should be online today.

      Reply
      • Hi Jonni, love your videos and am using your latest Paper Clay Mache regularly for my fairy house building, works great!

        For weather proofing, I discovered an article that tested out various methods, with Marine Varnish being the winner. I coat my finished work with 2 thin coats of it, and it had worked out great! I know Varnish can have fumes, and while it doesn’t bother me, it may for some, so I typically only apply it in a ventilated room.

        Reply
        • Thanks, Celena. I tried the marine varnish once, and it cracked as soon as the sun hit it. I must have done it wrong, because I know a lot of people swear by it. Thanks for letting us know it worked for you. BTW, we’d love to see your fairy houses. 🙂

          Reply
    • Wow that’s a great idea!!!!! I’m not sure what it is but I have an idea. Thinking it’s heavy duty and can keep oil water ect. Out of engine parts.

      Reply

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