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!
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 this kind of material.[toc]
So what causes air-dry clay to crack anyway?
Although I prefer polymer based oven bake clay hands down, I used to work with the kind that just dries on its own too. I know it is a different ball game but it’s got its advantages too. However, one of these disadvantages is that self-hardening, as it is sometimes labeled as – air dry clay has a cracking tendency, due to these reasons:
1. It is water based, mainly, 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 happens, and one thing you’ll notice is that its color will lighten too.
It has a different makeup overall, for one thing, one component is cellulose fibers, which give it a certain flexibility to it
Also, it 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)
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 big window of opportunity. So let’s dive right in!
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.
Think 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…presto, no show!
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 Ziplock 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 – whether in a Ziplock bag or one of those food storage containers with a secure lid, and 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. I made this mistake once and I was sorry I did! 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.
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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. Another technique that works well is “rough 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 paste to each part before I joined together the two objects.
The thinner the objects being made, the more delicate they will be eventually. If any parts of your clay project are thinner than a fourth of an inch I’d suggest the use of an armature or find ways to build it up more.
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.)
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.