Is Your No Bake Clay Cracking? Repair Your Projects Like a Boss!

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Is Your No Bake Clay Cracking? Here’s How To Fix It!

Are you toiling with gusto on a project using air dry clay, only to notice unsightly fractures happening out of nowhere? Your project is still not finished and already that no bake clay is cracking! Gads!

It’s making you think that the advantage of being able to skip the concern for kilns and ovens came with an unexpected drawback.

Fortunately, I felt your pain once and I can show you what to do after managing to “crack the code” about clay and its makeup!

✅ Psst…Hey crafters, if you’re just curious or in a hurry…This brand of air dry clay is one of the best quality.

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no bake clay cracking

So What Causes Air Dry Clay to Crack?

Although I prefer polymer based oven bake clay hands down, I used to like to work with the kind that just dries on its own, too. Air dry clay is also known as “self-hardening” clay. It’s got it’s advantages, but it also has a cracking tendency, due to these reasons:

1. It is mainly water based. As it gets prolonged use out of the box, that moisture evaporates. How quickly that happens depends on your environment among other factors.

2. Air dry clay reaches its curation period within 2 days. It will shrink (slightly) as it cures, and one thing you’ll notice is that its color will lighten, too, as this happens.

3. It has a different makeup overall, for one thing, one component of air dry clay is cellulose fibers, which give it a certain flexibility.

4.Lastly, air dry clay is not altogether heat and water resistant when fully cured. (This goes without saying, but here goes: don’t use it to make dishware, anything you might plan on for eating and drinking utensils.) It is best for decorative use only.

How To Stop Air-Dry Clay From Cracking While You Work

Let’s say you’ve got a project well under way…and (gasp) you’re noticing a few of these dreaded fissures happening…good news!

There are some things you can do right now to repair it and quickly too; as I mentioned earlier, the curation period of 2-3 days does not leave a wide window of opportunity. So let’s dive right in!

cracking clay

Once way back in the day, I took a ceramics class that was part of my college art major and we learned about the importance of creating “slip” when mending cracks or adjoining small objects to one another. “Slip” is a kind of watered-down clay paste that you mix together which is made of, you guessed it, clay and water.

If you’re seeing hairline cracks at the early stage of drying, this action of creating and applying slip, can really help prevent bigger ones. 👍

Think of it as a form of spackling plaster if it helps. Using a sculpting tool to stir it together; it should be about the consistency of glue. Using the clay paste mixture and some special tools, spread this mixture onto the splitting area.

You might want to use your fingers too and the spatula looking tool. to push it in depending on how deep it is.

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Can You Prevent Air Dry Clay From Cracking Early On?

I remember having to be careful storing this stuff – it had to be in a Zip-lock bag no questions asked. (Where I come from – the Southeast – we have more humidity than you can shake a stick at.) Be sure you store your clay slab carefully, like in one of these storage containers with a secure lid. (I notice there seems to be a dearth of for-clay containers out there.) Make sure it goes into a cool, dry place.

Do not add water to the slab itself; due to the excess of moisture being the reason for the fissures occurring early on, just store it as I described above. Sometimes I would mist the slab with a water bottle for good measure before putting the lid on. Just a small amount like that will work fine.Air dry clay is made with cellulose fibers that give it its flexibility so out of the box, a little kneading on your part is all that’s necessary.

Related Post: How to Store Your Clay-Best Practices

Special Techniques To Prevent Clay Cracking

If you are someone who enjoys making objects with more detail, you may want to consider the use of an armature which will give a little added stability. The thinner the objects being made, the more delicate they will be eventually.

Pro Tip: If any parts of your clay project are thinner than a fourth of an inch, I’d suggest the use of a wire armature or find ways to build it up more. Thicker pieces withstand cracking better!

The only problem with armatures, is that even though clay shrinks as it dries, the armature of course,remains as is. Make sure you create one that is flexible enough to withstand this change.

Second tip: Try to periodically turn your objects so they have a chance to dry more uniformly.  Clay will start drying from the outside in – depending on the thickness and girth of your object.

Don’t Try to Expedite Drying

Another pro tip to keep in mind is to resist the temptation to speed up the drying process. The faster no bake clay dries, the less resistant to cracks it will be as the moisture evaporating more quickly will make it more vulnerable.

This includes unintentional actions, too – let your project sit out in a cool, dry place, away from heat vents and other warm places. Just allow it to do its thing naturally. If you want, you could even slow down the process a little, by lightly covering your project with something like plastic wrap or foil…be sure to pierce a few holes in it for ventilation.

“Rough Up” Multiple Clay Parts to Minimize Cracking

Another technique that works well is “roughing up” the side of your project in which you will be adjoining multiple clay pieces together. Using a knifelike tool (I had one that resembled a dental hygiene pick) I made what looked like criss-crosses on both sides of the project, and added a little slip paste to each part before I joined together the two objects.

A combination of roughing, and application of slip helps give more complex objects the right kind of “infrastructure” they need to hold up long term, and resist cracking better.(Hey, just like the way buildings are built, in a way.)

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Are Some Brands of Clay Better Than Others?

Yes, sometimes it can all depend on the brand! The above suggestions work well as long as you’re using a quality clay with a good track record.

Case in point…Here’s a handful of little clay figurines I made years ago. I didn’t experience cracking, but in time a few of their limbs did break off. Bummer!

clay figurines broken places

Now the little guy on the left remains intact, but I think that was because I molded him into a sitting pose, and the others’ arms and legs are spread out. My point is, I think this was a more low-grade brand of clay I was using at the time. Maybe?

✅ If you’re looking for a brand of self-hardening clay that is pretty resistant to cracking…
look no further than these made by Das. I’ve used it before, and it beats others I’ve used HANDS DOWN.

Now it kinda has a funky smell to it, so you may want to have adequate ventilation while working. A lot of hobbyists and sculptors LOVE it and have voted it as one of the best brands!

The following clay products are from Blick Art Materials…one of my favorite venues for finding great art supplies. I am an affiliate of Blick so any purchase you make through the links below I may earn a commission at no cost to you.

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In conclusion…

Summary

Hope I could be of help! I’m a Georgia native and we are surrounded by red clay LOL 😁. When your no bake clay starts cracking, don’t panic, it can be fixed – just get to it quickly as you can and the above methods will not take that long.

So I hope you will take this advice to heart and apply it; as it helped me out when my projects were suffering a little back in the day (before taking classes) There’s no reason to give up on self-hardening clay if you really want to use it – it costs a little less than the polymer kind and is relatively non-toxic which makes it a great choices for kids and adults alike who want to learn sculpting techniques.

Updated: 03/16/2023 — 10:06 PM

10 Comments

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  1. subarna Talukder

    Hi Jennifer! Good information! I am planning to do some project that involved wood and clay. Does air dry clay sticks to wood surface on its own> Or, should I use PVA glue? Also, I am planning to paint my clay with oil paint. Can I do that directly after it cures? Thanks!

  2. Thanks for stopping by! I don’t think I have used wooden armatures for clay projects…mostly wire, depending on the project’s size. Some clay figurines I have made in the past that were real small I didn’t need an armature for at all. To paint finished clay projects I usually used water-based paints and varnishes. PVA glue being water based might work fine though. Good luck with your project and let us know how it goes 🙂

  3. Hello! I recently tried to make a large bowl out of air dry clay. I laid a 1/3” thick slab over a glass bowl, smoothed it down with some water, cut edges and left to dry (upside down). However, when I looked at it 24 hours later, it was totally cracked all over. Do you have any recommendations? I’m trying to make a large custom bowl for my yarn and can’t seem to get it right

    1. Thanks for sharing Meg – a yarn bowl – now that sounds like a great idea!

      So sorry you ran into this all too common problem – If you have any remaining moist clay, my suggestion would be to create some “slip” (see paragraph 2) – a part of clay to two parts water so it is kind of goopy – and use it to seal in the cracks on the bowl. How deep are the cracks anyway? One-third an inch is pretty thick as far as a slab of clay goes.

      The “slip” (clay/water paste) should help mend the cracks…depending on how deep they went you may want to use a sculpting tool to work in in and smooth it over the surface.

      Good luck to you! Let us know how it goes for you.
      -Jennifer

  4. I’ve just stayed with sculpting in clay, first a horse head in non hardening clay then a reduction/ raised relief of a race horse on a flat slab using air dry clay and just this just week a full body horse with the same air dry clay. The flat surface piece is fine, no cracks but this last one, with the wire armature is basically cracking to pieces as it dries. Its past the patching phase and I hate to just toss it if there is a substance that I could mix with some type of adhesive and use a color to fill and hold the pieces together and create a somewhat abstract form of my work to hang onto or give to my daughter. Any suggestions?

    1. Oh goodness….Any chance I could see a picture of your horse sculptures? I may be better able to make some suggestions for repair products that way.

      Dang, I love horses, such beautiful creatures; in art form I can sense how a three dimensional sculpture – the last one, right? will have a certain amount of delicacy. What did you make the armature out of if I may ask – what probably happened is that while the curing took place the armature remained as is which may have led to parts breaking.

      Truth be told it wouldn’t be a matter of what you can apply to the clay itself as much as it would be a matter of the type of armature as it all comes down to the universal law of clay shrinks while it dries…can the armature support it?

      Anyway I would love seeing a picture of your horse sculptures! (I know, the limbs are going to be the most delicate part!)

  5. Hi there I have a 14 year old cat passing and I bought Crayloa mold non toxic for kids and pets… Well I finally after trying 2 days got my cats prints molded… well this am it is all cracked .. Any way to save it as I can’t afford the vets high priced costs on Disablity.,, please help!

    1. Do you have a name specific for the mold? I could look it up and find out more about it…Sorry I don’t buy Crayola products, unfortunately. I use Das and another brand of terra cotta and slate gray color modeling clay which are very good. But terribly sorry to hear about your situation, I lost my youngest cat Sputnik shortly after Christmas so I sympathize! He was only 3 years old too by the way so a total mystery…very much missed.

  6. Aha, slip is my answer! No matter how much water there was(n’t) in the clay, I always have cracks. Thanks for this easy-to-read instruction and recipe, it’s going to help me a lot.

    1. You’re quite welcome! Yes, this was one of the most valuable tips I got from ceramics class😊. Just remember the mnemonic device: “slip through the cracks”

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