I have been making bonsai type plant pots for a few weeks now. I buy the clay, make them at home, and then take them to a pottery place where they fire for me. Since these pots are for
my collection of cactus and succulents, I want them to look rough and match the plant so I am not doing the typical perfectly round pot. I have been trying sodium silicate to create a cracked look and the results have been excellent.
I am very happy with my results before glazing. I purchased some Coyote Shino glazes as they seemed to create the look I want, which is darker coloring in all the cracks and crevices with slightly lighter coloring on the surface.
I glazed 6 pots using various Shino glazes but the results were not what I was hoping for. Mostly just came out solid coloring everywhere on the pots. The owner of the shop that did the firing said I have to put the glaze on heavier where I want it darker and
lighter where I want the color lighter. Does this sound right? Should I put it on heavy so it gets in all the cracks and then lightly wipe off the surface? Any help is appreciated. The picture I attached is of the glaze look I am trying to create. Thanks
Posted 02 September 2013 - 08:18 AM
Posted 02 September 2013 - 08:57 AM
And yes, I would suggest doing as you stated, put the glaze on thick, then sponge off the areas you want to be lighter, similar to using mason stains.
Posted 02 September 2013 - 10:02 AM
Thank you for the reply. I will try that on the next few pots. This is a picture of one I made but have not glazed yet. I like the way it came out so do not want to glaze it until I understand better how to get the look I want. The 2nd picture is one I did glaze but as you can see very little contrast.
Posted 02 September 2013 - 10:15 AM
You have got the cracking nicely under control. Do you mind telling us the strength of the sodium
silicate solution you use?
You may me interested in combining the sodium silicate with slip, as in this video:
... and at:
Posted 02 September 2013 - 10:38 AM
Black underglaze works well because if you don't like the look you can usually soak and scrub it all off. Avoid blue or green because they tend to stain the clay more than others.
Contemporary Fine Colored Porcelain
TRY ... FAIL ... LEARN ... REPEAT
Posted 02 September 2013 - 11:30 AM
Peter, I am embarrassed to say I have no idea what strength the sodium silicate is. I just purchased a small container of it at the clay store. I put it on the pot with a brush and where I wanted larger cracks I put it on thicker. Great video!
Chris, After you put on the oxide wash and wiping it off can you then put one of the shino glazes on the surface areas?
Posted 02 September 2013 - 11:50 AM
How viscous is the sodium silicate to bought; treacle, maple-syrup, .... ?
[I want to say golden-syrup but that may be a UK-only product.]
Yes, you can put a glaze over a wiped oxide wash. If it bleeds into the glaze too much,
you might want to go for a wash with a less-reactive (and more expensive) stain.
You might also like:
... skip to near the end of the video to see if you like the effect.
Posted 02 September 2013 - 12:06 PM
Yes, I do like the look in this video also. I would say the silicate I have is about the same density as maple syrup, maybe a tad thiner.
The inspiration for my trying to make these pots for my plant collection came from seeing these pots by a talented man in CA. If I can do this half as good as him I will be thrilled.
Posted 02 September 2013 - 12:14 PM
These are a few more I made awaiting glazing. I do not want to glaze them until I have more confidence in what I am doing. I hate to ruin them with improper glazing but will try to get some oxide and give it a try. I appreciate all the help.
Posted 02 September 2013 - 12:46 PM
Really nice looking pots. To return to your original question re thickness of glaze, I would disagree with the advice you received - toput the glaze on thicker where you want it to be dark. I use Coyote Shinos quite a bit and all give you brown where thin and a lighter color(depending on the Shino you are using) where thick. Although my experience is more limited with high fire reduction Shinos all that I have tried give the same effect i.e. dark where thin, lighter where thick.
Posted 02 September 2013 - 01:19 PM
Well if that is accurate then it will be a much bigger challenge. Getting it thick in the cracks and wiping the surface seems pretty easy but the opposite seems much harder. I think it would be almost impossible to get it thicker on the surface without it entering all the tiny cracks. I will be firing at cone 6.
Posted 02 September 2013 - 01:58 PM
"Chris, After you put on the oxide wash and wiping it off can you then put one of the shino glazes on the surface areas?"
Sorry I don't know anything about using shino glazes and its interactions with oxides ... but I do know that you can control your effects to a precise extent by using the washes and underglazes. I have used regular glazes and lichen type glazes over them with no problems.
Contemporary Fine Colored Porcelain
TRY ... FAIL ... LEARN ... REPEAT
Posted 02 September 2013 - 02:52 PM
The suggested washes correspond to suggestion 38 in this "things to do with shino" list
For the record your description of the sodium silicate viscosity suggests that it is probably 75 degrees twaddell.
[In the UK potters sodium silicate solution is sold in two strengths 75TW and 140TW, with 75TW being the more
fluid. Degrees twaddell is a massively obscure scale for measuring density.
... although to be fair to the original users it would have been easier to use for density calculations in the days
before pocket calculators.]
Posted 02 September 2013 - 03:47 PM
Dry Ridge Pottery
Posted 02 September 2013 - 03:49 PM
Peter, Thanks for the reply but the link for the shino list is not good.
Posted 02 September 2013 - 03:50 PM
Thanks Diane, The look I am trying to accomplish is dark in the cracks and lighter, although not what I would call light, on the surface.
Posted 02 September 2013 - 06:12 PM
I noticed on one of the web sites where I purchased some glaze that they sell a number of different oxide washes such as copper, manganese, cobalt, etc. Would all of these work as the first coat to fill in the cracks and then try different glazes on top?
I have about 25 pots waiting to be fired for the first time at the local clay shop here and decided I worked too hard on them to ruin them by messing up the glaze. I spent the afternoon making small clay rectangles, added texture to them, numbered each one on the back, and then added some sodium silicate to just the upper half of each one to form cracks. I will take these in to be fired and then try the various shino glazes and oxide washes on them as test pieces. Then I will have them to pick and choose the one's I like for the actual pots.
I greatly appreciate everyone's input and will let you know how things turn out.
Now I have to start reading all the various posts on this site and hopefully gain some more knowledge on my new addiction!
Posted 02 September 2013 - 06:35 PM
Posted 02 September 2013 - 07:07 PM
Wow Marcia, just beautiful! Since I live a long way from MN can you explain this process? What is obvara?
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