Getting the glaze to lay flat and remain glossy has been the most tricky part of the whole 3D-printing ceramics process. When I apply too little glaze, it leaves a matte surface. Too much glaze causes it to pull away into clumps. The perfect, unform glossy goal is a narrow range! I’ve so far tried dipping the pieces into glaze, and brushing it on. Surprisingly, the dipping method is more difficult to control since the glaze is very viscous (I should probably thin it) and doesn’t drain off the part uniformly. I think spraying the glaze with an air gun is the way to go, but I haven’t tried it yet. I believe spray application is what’s used for commercial dinnerware, etc. I’ve been using Amaco Celebration high-fire glazes. The colors here are Baby Blue, China Blue, Orangerie, and Light Grey.
I admit that I’ve been in a hurry for the glaze to dry before firing, and have used a heat gun to speed it up.
I added a 2mm hole into the .stl to prevent air entrapement when printing with the open end facing the tank of resin. These vases were actually printed directly on the build plate, and the bottom was pulled apart when trying to unmount the object from the plate. I’ve since started using supports to print vases like these (but only on the base - no supports on the sides), and that has worked very well.
I orient the vase so that the bottom is flat on the build plate in Preform, then use the automatic support generation tool (with “internal supports” unchecked). It will completely cover the bottom and sides of the vase. I then manually edit the support points, and use the box selection tool to remove all of the support points on the side of the vase. The support density is very high for ceramic. It almost seems like it would be equal to solid material at that density, but it crumbles away, leaving the part in good condition. I use sandpaper to remove the nubs on the part.
You may find that going totally flat may lead to some print failures, at the base/support interface… M.A.Y.
If you do, you can do the same thing you are doing, but add a 10-20 degree tilt to your part. This will allow the base to be built progressively which reducess sheer forces on the first few layers of the base.
This applies to any resin, and is just an FYI if you run into any problems/failed prints that are based around the beginning of the model geometry.
This is amazing! Thanks for posting. Curious to know the thickness of the vases and how you felt they hold up. Would you say these are good for actual use as a vase/cup at that thickness?
I’m thinking of doing some espresso cups myself, obviously we would like to print as thin as possible to conserve reisn, but they need to hold up to regular use as well.
Would be awesome to see some pics of the vase in context to get an idea of scale as well as the unglazed version. Have you tried firing them without a glaze? I kinda like the white you see in the marketing pics…
Thanks! This vase: Wooden foot for 3D-printed ceramic vase was printed with a 1.5mm wall thickness, and it is OK for a decorative vase – watertight and everything. It’s fragile, though, and too thin for a cup or something that would be handled frequently. I’d probably go 4mm or more for a cup. The material is porcelain, and at the recommended firing temperature, it will very likely be watertight without a glaze. It has a nice matte appearance, and feels like 320 grit sandpaper to the touch.
Nice thanks for the detailed info. What do you mean when you say the material is porcelain? I thought it was printed in ceramics? If im not mistaken porcelain is stronger and can thus hold thinner features than conventional ceramics, but now you got me all confused as to what actually is the formlabs ceramics material.
Ceramic is an umbrella term (whose scope is actually disputed even among experts BTW ). Porcelain is a ceramic, but it also represents a lot of different actual materials. The term porcelain is generally used to describe a ceramic shaped using traditional pottery techniques, rather than being attached to a given material/mechanical characteristics.
I think @BenKrasnow’s usage of the word porcelain was motivated by the watertight nature of the material without coating which if one of the characteristics used to define porcelain, as opposed for example to a refractory brick which can be ceramic, but is generally is too porous to be watertight.
Interesting, I was under the impression that fine porcelain refers to a specifically different form of ceramic (with a different clay mix) than something like slip casted ceramics… but im no expert.
Ceramic is a very broad term, depending on what industry you’re dealing with. They make ceramic cutting inserts for lathes and mills, and Tungsten Carbide is sometimes considered a ceramic. Quite a world away from what I drink my coffee out of.
All Porcelain is Vitrified- meaning its fired high enough to become an actual glass.
As such it is watertight without the need for a glaze- ( Which vitrify at lower temps than the clay body requires. )
Where this matters is, for example, in tile. For exterior applications and shower pans you want a porcelain bodied tile. Water intrusion into the tile body on exterior tile can result in the tile fracturing if the temperature drops below freezing.
For other interior applications you can get away with a bisque fired body for the tile with just the thin surface of glaze being vitrified.
Most coffee mugs are not made of porcelain. They are low fire clays that are glazed.
Certain very fine grained clay bodies fired at very high temps ARE physically stronger than low fired ceramics and so you CAN get away with very delicate thin walled pieces.
You also tend to correlate porcelain to thinner- more delicate looking objects because as the firing temperature rises, the shrinkage increases and the thicker the part- the more internal stresses created in firing ( At high temp- the part shrinks as it vitrifies- but then shrinks further as its temperature comes down )
These stresses can result in a kiln explosion.
Stoneware is essentially very thickbodied ware fired at porcelain temperatures… but they compensate for the stresses by filling the clay body with actual crushed vitrified ceramic or actual rock to reduce the shrinkage in thicker parts and thereby reduce the stresses.
In resin casting we pull the same trick by filling the mixed resin with calcium carbonate or other materials that dramatically reduce shrinkage.
). Porcelain is a ceramic, but it also represents a lot of different actual materials. The term porcelain is generally used to describe a ceramic shaped using traditional pottery techniques, rather than being attached to a given material/mechanical characteristics.