I was having problems with getting the glaze to stick to ceramic part. I learned a very helpful tip from a blog post by Jessica Rosenkrantz (who knows quite a lot about 3D-printed ceramics!). https://n-e-r-v-o-u-s.com/blog/?p=8115#print The trick is to bisque fire the ceramic piece after printing, then glaze, then fire to full temperature.
For vases, and similar shapes, I print with the base of the vase parallel to the build plate, with the open end facing the tank of resin. This will create a big airlocking problem, so I add a 2mm hole in the wall of the vase in the .stl using Meshmixer. I use the recommended support size and density, and then remove all supports on the walls of the vase using the box selection tool. The base is almost completely covered with supports – almost solid!
After printing, I clamp the build plate in a bench vise and carefully chip off the support blob with a end-cutting xacto blade (tiny chisel). Tapping with a hammer works much better than any other technique I’ve tried.
Standard cleaning with IPA, and let air-dry. I use coarse sandpaper on a piece of glass to remove the support nubs from the base of the vase and leave a flat surface.
I use the Formlabs recommended ramp and hold times, but change the maximum temperature down to 1040 C. The part is “bisque fired” and more delicate, but also more porous, which allows it to soak up the glaze.
I’m using Amaco Celebration high-fire glaze, and add equal volumes of glaze and water to a dipping container. I dip the part, and let dry by hanging it on a wire hook. After fully dry, I dip again, this time hanging it in a different orientation to let the glaze flow all over the piece. It seems 3-4 total coats works best for a nice silky smooth finish. I think the glaze could be a little thicker as well the 1:1 ratio might be too much water.
I remove the glaze from the base of the vase by rubbing it on a wet cloth held flat on the table.
After the glaze is fully dry, I fire it to 1250 C, at a ramp-up rate of 6.5 C/min (about three hours), and let it cool at 20 C /min or the kiln’s natural cooldown rate, whichever is slower.
hello ben,
thanks for all the information and documentation,
I have some questions,
have you improved in any way this workflow since 18’, as it is a little bit old I thought about asking if you have changed anything.
2.in 4. you mentioned that you use a lower temp, so it soaks the glaze, if you use the recommended temp the glaze does not stick?
thanks for all the data,
best regards,
franco
Franco, I haven’t done much ceramic glazing recently, but was also very satisfied with my technique, and wouldn’t change much. If the bare ceramic piece is fired to 1250, cooled, then glazed and fired again, the glaze will not form a continuous coat. The glaze tends to clump up and form islands on the ceramic surface. Bisque firing makes a tremendous difference.
hello ben, I bought the HF glaze, and do as you mention but the glaze finish with a lot of fissures it stays “sticked” to the print but as I wated to make it watertight I am afraid of not being. any recommendation? maybe a lower cooling ramp?
Did you bisque fire, then glaze with 3-4 dip dip coats? did the bisque fire, and for the application i can not use dip as i need to put it in an external surface but not the rest of it (not the circular phases of the cylinder if you want… see the picture). so i used a brush and painted 4 times…
Are the fissures hairline cracks or large smooth crevices? mmm I would say hairline cracks? they dont look superficial, sadly is difficult to take a good picture but I am putting an image in any case…
If the cylinder is solid ceramic, it may be expanding and contracting too much relative to the glaze layer. Can you make it hollow with a constant wall thickness? Double check your kiln temperatures, and make sure to follow the very slow ramp times. For a thick solid section like that, you’ll have to go very slowly.
saddly the inside I can not modified as it is an special structure, the thickness of the cylinder wall it is of 2.5mm do you think that i can re glaze the same part ? to try another slower ramp? or should i beging from scratch? also slower ramp times for the 6.5 °C too? or only the cooling section?
thanks a lot for the help!
