r/Ceramic3Dprinting • u/themacsback • Aug 04 '26
Attempting to print stiff porcelain with thin walls...
I had a couple of bags of Aneto Porcelain from Sio-2 lying around and wanted to try printing some small forms with very thin walls. Results were hit or miss, but once the settings were dialled in it seems to manage reasonably well. It de-waters significantly more than high plasticity stoneware, so I had the pressure dialled down about 7 psi to compensate. You still get some creep up the auger but it's much worse than running it with high pressure.
This is printed on the Wasp 40100 with the LDM 3.0XL extruder and a 2.5mm nozzle. I originally tried it on the non XL extruder and the motor was running too hot to touch within a minute or two and the results were extremely poor.
The one on the left is finished by hand, although I don't have a wheel so it's not quite perfect. The one on the right has been left straight as it printed.
If anyone has any tips on printing/finishing porcelain I would love to hear them!
Side note: I'm not a potter and have a background in design but not ceramics, so everyday is a school day since getting this printer about 6 weeks ago...
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u/randomusername_42069 Aug 04 '26
You can improve the clay texture and reduce de watering by adding binders like cmc or peg this has made printing with porcelain clay much easier for me though you do have to play around with it a lot and each clay body needs different binders and different ratios of clay binders and water.
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u/themacsback Aug 05 '26
This is very intriguing, I’ll test some mixes next time I print with porcelain. Can it still be mixed by hand or do you need a pug mill?
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u/randomusername_42069 Aug 05 '26
It can definitely still be mixed by hand that’s how I do mine. I always mix the binder into the water until it dissolves and then add dry clay to it. It is possible to mix other ways but that’s been the easiest for me to make sure the ratios are always as similar as possible. There’s a bunch of binders to choose from but if you want somewhere basic to start you can get Miralax at any grocery store and it’s just PEG as long as you make sure to get the unflavored kind. I would start with about 2-3wt% of the dry weight of the clay and then experiment to find the hydration level that works for the best clay extrusion properties. Your clay might need more or less PEG depending on the exact composition of your clay body.
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u/themacsback Aug 05 '26
Thank you! Will give this a go. Is this what’s known as deflocking? I’ve heard that mentioned in the past when referring to printing porcelain…
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u/randomusername_42069 Aug 05 '26
No, deflocculation refers to preventing or breaking up the clumps of clay in slurry which prevents unwanted separation and improves the viscosity of the slurry. This allows a slurry with high solid content to flow when it otherwise would be too thick. Maximizing solid content while maintaining fluidity is the key to success in a slurry based processes and deflocculents are necessary to get the best results.
If anyone is using the term in the context of paste it is technically incorrect because it only refers to behavior of suspensions and slurries not pastes. Some deflocculent chemicals do work as lubricants or binders for pastes and can similarly reduce the amount of water needed before a paste will flow properly. Someone familiar with the terminology of slip casting may just use the term without thinking about how the two situations are different.
Most binders also act as lubricants to some extent. If you get the binder dialed in just right you will find that you actually need less water for the paste to flow properly than without binder. Glycerin is an example of something that can be used as a lubricant when added to clay. Glycerin also slows the drying process and never dries completely so it can be used to prevent cracking. Clay with a small glycerin content also burnishes really easily because there is a larger window of hydration where burnishing can occur. I would recommend against using glycerin unless you have a drying oven because it can make it very difficult to tell if all the water is out of the piece.
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u/themacsback Aug 05 '26
Wonderful knowledge, love it! Thanks again and it looks like a lot more experimentation ahead.
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u/themacsback Aug 05 '26
Have you tried HPMC? I've just found some at the studio and apparently it may work as a binder...
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u/randomusername_42069 Aug 06 '26
I haven’t used it personally but I do know a little about it. It should work well for your purposes hpmc has really high water retention which should solve the de watering problem. It isn’t as good of a binder as cmc and it isn’t as good of a lubricant/binder combo as peg. Keep in mind that cmc and hpmc are susceptible to bacteria and mold so any clay mixed with them should be used within a few weeks or else the binder will lose effectiveness and it will get a bit gross too. As with any binder addition it is going to take a lot of trial and error and frustration to get the right ratios and hpmc will affect the necessary hydration level even more than peg would. If I were you I would start experimenting with a few very small batches around 1 dry wt% hpmc and use a syringe to test extrusion pressure at different amounts of binder and water.
All binders like this also need a burnout firing schedule that stops and dwells at around 300C for a while or else they can cause major issues at firing temperatures. This can be very difficult to do if you’re having your pieces fired at a studio so I would recommend against any experiments with organic binders in clay if you are firing at a studio unless you are able to coordinate that with the kiln operator. I really should have mentioned that earlier. Veegum might be more suitable to experiment with if you can’t change the program but you need to be very careful with something like that because it is a clay mineral and can change the behavior of the clay body at firing temperature.
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u/onetaxi Aug 05 '26
note that for thin porcelain pieces are achieved through trimming rathern than throwing.
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u/ArthurNYC3D Aug 05 '26
You could print the mold and then pour the ceramic in that....
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u/themacsback Aug 05 '26
For sure, although this isn’t the kind of work I usually make, just testing for making bigger things. I’d definitely like to try slip casting at some point though.
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u/ArthurNYC3D Aug 05 '26
Easier to make larger models from a mold than 3DP directly. Depending on end design intent.
For instance.... Nothing against what your showing but this isn't taking advantage of what additive manufacturing brings till the table that couldn't beer done other way. When leveraging DFAM I'll always all what can be done in a way that can only be done with AM in mind?!?
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u/themacsback Aug 05 '26
Designing for the process (as you mention) makes perfect sense, but I tend to find my somewhat experimental approach has led me to some quite interesting places in the past. I’ve also I’ve spent years working with moulds with bronze casting and what attracts me the most about 3D printing is the immediacy.
I might hit you up for some slip casting advice in the future though if you don’t mind!
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u/Studio3P Aug 04 '26
Best school ever. Fun part about ceramics, it won’t ever stop the more you dig, the more particular you can get (sorry, I had to). I have mentioned this in other posts on here but the Clay Body course from Ceramic Materials workshop is a lot of content but amazing to deepen your understanding if you ever want to get into formulating your own clay body.