Artist's Choice: Epoxy or Air Dry Clay for Sculpture?

November 04, 2018

Artist's Choice: Epoxy or Air Dry Clay for Sculpture?

Artists are curious people. It's natural that we might wonder how we can use different materials. If you're new to sculpting, or looking for an alternative to ceramic clays, I want to give you a brief intro into alternative clay sculpting mediums.

To cure or to dry? That is the question!

Artist clays that do not require firing in a kiln (like ceramic) or baking in an oven (like polymer) fall into two main camps:

1) Air dry clays, which are generally water-based

2) Epoxy clays, which cure rather than dry, as a result of a chemical reaction. They are usually sold in two parts that are mixed together.

Epoxy clay vs air dry clay

There are several distinct differences to consider when choosing between air dry and epoxy:

Price 💸
Generally epoxy clays are a bit more expensive. To give you an example, a package of Creative Paperclay (453g or 1lb) is around $12 US. The same amount of Apoxie Sculpt is $18 US. While price may sway your choice, it will likely depend on the other factors outlined below.

Dry Time 🕒
Air dry clays generally have no workable time limit. I like to call them "open clays" (taking my cue from painters here). Like ceramic, they can be kept moist for long periods of time and adding water to not-yet-dry clay revives it.

In contrast, once mixed, epoxy clays will cure within several hours (it varies from type to type), and there is no stopping it. I for one am not a fan of this, as I like to hem and haw over a sculpture for days and sometimes weeks.

That being said once dry/cured, both types can be sanded, drilled, carved, so you can easily go in a cut away parts and re-sculpt.

Sensitivities 🐱
There are some who say that epoxy clays give them skin reactions, and it is not unlikely since they can  utilize organic compounds to trigger the chemical reaction for the curing process.

Companies advise that the two-parts be mixed with gloves on (which I always do because it is a pain in the a** to wash the residue off), though many veterans swear they don't wear them and have suffered no ill affects. 

Air dry clays like Premier and Creative Paperclay are completely non-toxic. I am a brush-licker, so I am grateful for this. I am not howver suggesting you supplement your regular diet with clay.

Weight 🏋️
Epoxy clays generally cure stronger than air day clays, but consequently they are also heavier. This is neither good or bad, just something to be aware of.

Special tools 🔨
You don't generally need any specialized tools for epoxy clay (except to wash them really well, otherwise you'll never get the dried clay off), but there are extras that can make working with the clay easier. Many epoxy clay brands sells special fluids for smoothing the clay for example. 

While the shelf life of epoxy clay is usually over a year, you must take care not to cross-contaminate the 2 containers, otherwise you will trigger the curing process.  Epoxy clays are also used by ceramic artists to "glue" fired ceramic elements together, while still retaining the look of clay. Just so many options!

Epoxy is for me!

Given the above considerations, if you find that you'd like to give epoxy clays a try, some popular options are:

  • Apoxie Sculpt: probably one of the most well known types. Comes in a slew of colours. The company Aves makes a variety of epoxy clays (some firmer, some with texture), of which Apoxie Sculpt is the cheapest.
  • Magic Sculpt: Another very popular brand. About 5 different colours.
  • Milliput: more popular with hobbists, but great because it can be purchased in small amounts. Also only 5 colour options.

Clay and wire horse sculptures

Select uses

If you're like me, you might like to use epoxy clay only for select purposes. I use epoxy in 2 main areas of my sculptures:

1) Armatures
Since it dries incredibly hard, epoxy clay is perfect for ensuring you have a rock solid armature. I use it to fix areas in place where a lot of wires come to together to ensure they don't shift while I'm sculpting.

The only downside when doing this is that I have to wait for the epoxy to cure. Did I mention it's handy to have multiple sculptures going at the same time?

2) Thin or fragile areas
The legs of small horse sculptures or exposed ears are some of the areas that require extra strength. Epoxy clay to the rescue! Sculpting these in epoxy ensures that they are strong and less likely to break if mishandled.

Mini horse sculpture by Susie Benes

Epoxy clays are wonderful tools for sculpting, so whether you choose to use it exclusively, or you combine it with other clays, you are unlikely to be disappointed. 

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