Pugmills - What they are, how they work, and do you need one?

[@suedavidson7759]

At my guild, we use any cone 10 clay and mix it all together, sometimes have nice streaks of different colors. Never had a problem with separation or cracking for different clays. I would not mix cone 6 and 10 clay though. Our machine is reversible and has the de-airer. We do not clean the inside of the pug mill, we just leave it sealed up so it does not dry out. There is a chamber where the vacuum is produced that gets some clay pulled in to it, that has to be scooped out after the pugging is finished. We pug every month or two.

[@AdelBenDavid]

Thank you that was an amazing and very helpful video!

[@nancyhartshorne6491]

And thank you for this very informative video!

[@patspotpage]

Thanks Joe! Very useful info. A couple more thoughts...For someone who cannot get their clay locally and must order online, a pugmill could allow them to order dry clay and mix it in their studio, saving money on the clay purchase and shipping costs. That could be a factor in the decision and ROI. Also, the time saved in clay prep for production potters is time that can be spent creating, so that is also a consideration, albeit maybe not a huge time savings based on your comments. Also, I've seen people comment that they didn't use their pugmill often enough and the clay dried in it, making it very hard to clean. Not owning one myself, I can't say how long that takes, but for those who wouldn't use it often it could be an issue, I suppose. No doubt many will benefit from the insight you've shared. Thank you!

[@OldForgeCreations]

Unfortunately, I'm not sure it's any cheaper to make your own clay. The water is only around 1/4 of the weight of plastic clay, so buying dry powder ingredients would only save a relatively small amount in shipping (so 100kg of throwable clay would require around 75kg of dry ingredients). And in my experience the material cost per kilo is often more than the clay cost per kilo, so you can actually pay more for the ingredients to make your own clay than just buying premade. The Shimpo has a pretty good seal on both ends, but I can definitely see that drying out could be an issue if left for long periods of time even with the seals. And would be worse on any pugmill without those seals!

[@chaotic_goodness]

Great video! So when we clean our pug mills at the shop, we don't take them apart. We pour clean water into the hopper, mix it, extrude it, repeat until clean water comes out. It takes a couple of hours, but the machine is doing the work. I don't think we've taken one apart in years. Not for anything except replacing the gaskets.

[@chaotic_goodness]

I should also mention that we generally add deflocculant to the rinse water to help loosen the clay up.

[@teethree]

Agreed totally, correct explanation, and I will not get one even for free, just because of the "cleaning time", I 'm quicker with my slap and "fold" method for getting the air out of clay, just reclaiming about 10 kg (a bucket full) once a month

[@OldForgeCreations]

There's a lot to be said for finding a basic manual technique that works for you and sticking with that, it's so much cheaper, simpler, and more space efficient!

[@jks3943]

I am making a hand crank PM out of an old meat grinder. Im just a hobbyist and only reclaim mine once a year. They are just way over my pay scale. 😮

[@OldForgeCreations]

I've often wondered whether it would be possible to use the basic concept of the deairing mill and the mechanism of a meat grinder to make a hand powered deairing mill. The vacuum pump can easily be bought separately and is a tiny fraction of the overall cost, but I can see it being a challenge to get the build design right.

[@jks3943]

@@OldForgeCreationsim still working on it. Got a reduction gear drive and plan on attaching a motor.

[@nancyhartshorne6491]

I visited a studio that used different clay bodies but ran all scraps together through a mixing pugmill and simply had a "studio" clay that they used when a purer color didn't matter. Do you see any downside to doing that? I use porcelain, white, speckle white, speckled tan, and Terra cotta colors. A mixing pugmill could combine them enough to achieve color and shrinkage consistency, right? Or is this taking a risk?

[@OldForgeCreations]

I think a pugmill would definitely mix them well enough to avoid any major issues, especially if they were fed through a few times. The question would be whether the clay ended up having a sensible firing temp (mixing a cone 6 and a cone 10 clay might give a clay that matures at cone 8, but that's not much help if you only fire to cone 6 and 10) and how much the blend would vary between batches

[@jakehartshorne6507]

@@OldForgeCreations Thank you! They all have the same firing temp.

[@suedavidson7759]

At my guild, we use any cone 10 clay and mix it all together, sometimes have nice streaks of different colors. Never had a problem with separation or cracking for different clays. I would not mix cone 6 and 10 clay though. Our machine is reversible and has the de-airer. We do not clean the inside of the pug mill, we just leave it sealed up so it does not dry out. There is a chamber where the vacuum is produced that gets some clay pulled in to it, that has to be scooped out after the pugging is finished.

[@IsinMoon]

When I saw “pug mill” I thought you meant a puppy mill that breeds pugs 😂

[@RobynHardyman]

Thanks really helpful. If you want to soften new clay that's too hard to use from the bag, do you have to add some water in the mill or does the mixing itself soften it up enough? I only use one clay, so would always have some in the pugmill, would that mean not having to clean it, or would the bits dry inside do you know? Thank you!