Jump to content

Two-Tone Effect


Paroan

Recommended Posts

Hi,
 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

post-59092-0-74960800-1378127469_thumb.jpg

post-59092-0-74960800-1378127469_thumb.jpg

Link to comment
Share on other sites

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.

post-59092-0-88746300-1378134062_thumb.jpg

post-59092-0-72352800-1378134129_thumb.jpg

post-59092-0-88746300-1378134062_thumb.jpg

post-59092-0-72352800-1378134129_thumb.jpg

Link to comment
Share on other sites

You can also get this effect before glazing by using a red iron oxide wash ... Paint it on and wipe it off the flat surfaces, leaving most behind in the cracks. Or you could use underglaze the same way by letting it dry in the cracks while washing off the main surface. Let it dry then add more or wash more off depending on the look you want.

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.

Link to comment
Share on other sites

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?  

 

 

Paul

Link to comment
Share on other sites

Poroan,

 

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.

 

Regards, Peter

 

You might also like:

... skip to near the end of the video to see if you like the effect.

Link to comment
Share on other sites

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.

 

post-59092-0-01360200-1378141547_thumb.jpg

post-59092-0-78746800-1378141565_thumb.jpg

post-59092-0-29433800-1378141585_thumb.jpg

post-59092-0-01360200-1378141547_thumb.jpg

post-59092-0-78746800-1378141565_thumb.jpg

post-59092-0-29433800-1378141585_thumb.jpg

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.  

Link to comment
Share on other sites

"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.

Link to comment
Share on other sites

The suggested washes correspond to suggestion 38 in this "things to do with shino" list

http://tinyurl.com/q4fja5

 

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.

http://en.wikipedia.org/wiki/Twaddell_scale

... although to be fair to the original users it would have been easier to use for density calculations in the days

before pocket calculators.]

 

Regards, Peter

Link to comment
Share on other sites

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!

 

Paul

Link to comment
Share on other sites

Here is the thread from the topic aesthetics. There are three. You tubes on there about the firing. the recipe is also there in the discussion. It is one of the most simple techniques I have ever done. no glaze, no smoke. Things happen before your eyes. It is a potter/pyro perfect experience.

Am having trouble pasting the link. Go to Obvara firing techniques under the topic Aesthetics in the Forum.

http://ceramicartsdaily.org/community/topic/4635-obvara-firing-technique/

Did it! Go to this link. Up in Smoke has been doing a lot of this too.

 

marcia

Link to comment
Share on other sites

Couple of ideas for you . . .

 

You could start with a clay body that fires dark brown or black, apply a white slip to the outside, then apply your sodium silicate and stretch the form.  That would give you the dark clay showing in the exposed cracks and white on the surface.  I think if you look closely at the first picture of the pots that you cited as inspiration, that is what the potter may have done.  For final firing, you could forego glazing altogether and just apply a wash of soda ash or ferro frit to give a sheen to the surface.

 

Another approach, as suggested by Chris, would be to apply a red iron oxide or black iron oxide wash to the pot after it was thrown, then clean the oxide wash off the smooth surfaces.  Bisque fire --  that seals the oxide wash better to the clay body.  Again, I would forego the glazing and just apply a soda ash wash or ferro frit wash to give the surface some sheen.

 

I use a combination of white slip, rutile wash (rutile in some water), and black underglaze to create a surface texture for some of my vases.  I apply the slip and colorants to the clay while building the forms, then bisque.  For glazing, I leave the exterior plain and just let it fire naturally.

 

post-2190-0-00605800-1378174873_thumb.jpg

post-2190-0-00605800-1378174873_thumb.jpg

Link to comment
Share on other sites

So are you saying to apply the oxide wash once the pot dries but before it is fired the first time? I did not realize you can apply these before firing.

I know you are saying to forgo any type of glaze after that but I do prefer to be able to create various color effects.  I could try it both ways to see what I prefer.

Link to comment
Share on other sites

You can apply an oxide wash at various times . . . wet clay, leatherhard, dry greenware, or to bisque.  When working with slips, I prefer to apply them at the wet stage and develop the patterns, texture and effect using brushes, sponges, and other tools and overlapping and blending the colorants and slip.  But you could apply them to your bisque if that is the stage the pots are in.  You can get your color effects just using the oxide washes, or underglaze washes; you don't need to depend on glazes for adding color. 

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use.