Oxide question

[mwar15]

For those pot heads…..

i’ve really started enjoying using iron oxide for my pots. I discovered a 5 gallon bucket literally of yellow iron oxide and black iron oxide powder at the studio.

Has anyone use these as a coating? If so any ratio powder to water with examples?

This is just a rough recipe I whipped up on a test tile. I Think it’s a quarter teaspoon of powder to probably 3 tablespoons water, then brushed on. 1-4 coats

 

[Leo in N E Illinois]

Is that before firing? Or after firing?

@sorce is always around, he might have hands on experience with iron oxides.

@ABCarve @Pitoon @penumbra and I am sure I am missing a dozen other good potters on here.

 

[Pitoon]

@penumbra uses a lot of oxides. I'm about to order some black myself.

 

[mwar15]

The photo is from a test tile after bisque firing

 

[mwar15]

Should also say I am firing cone 6 electric

 

[sorce]

I think "what you see is what you get", is quite applicable as far as your mixture ratio. So once it's doing what you want, that's a good mix.

I don't think "what you see is what you get" will be applicable to the colors, over 2012F, they will probably both look the same. I'd be interested to see the results.

Meowever, Black Iron Oxide can become a problem without care, because it lacks O molecules present in RIO, so it's "reduced" if you will.

Are you Firing with a downdraft vent?

Even with a well vented kiln, I'd assume it still possible for a piece to remain in a neutral atmosphere depending on location and surrounding pieces.

If say, you have a piece in the center of a kiln surrounded by other pieces that off-gas heavily throughout the firing, it is possible your BIO will not reoxodize, which will make it an added flux (as opposed to an anti-flux if oxidized).
So should you ever glaze over a BIO washed piece in this scenario, you may find the glaze run where it didn't before.

Though this is very unlikely, the fact that RIO and BIO are essentially interchangeable color wise, it's best to just stick with RIO. And since YIO is merely a slightly less powerful RIO, RIO can be used most universally.

Sorce

 

[penumbra]

Has anyone use these as a coating? If so any ratio powder to water with examples?

Oxides are not the same concentrations thus there is no formula except the formula that works for you from any given batch. Coating is a bit off, it is a stain, particularly for the iron oxides, in my experience. All oxides stain and some , like rutile, do tend to "coat" more, but the staining is really what we are after. I have also noticed that the iron oxides (there are dozens of them) work pretty well without a fixative, though colors will change over time and weathering. Most studio potters use a fixative like gerstly borate or silica to stabilize the stain or oxide and to give it better cohesion through and after firing. 10% is commonly recommended. Too much will give a glossy effect and some of the other oxides like manganese and copper tend to get a bit glossy on their own. I am always struggling with this myself. A little glossy is ok but too much is ..... well, too much.
I have been using mostly Mayco oxide stains which are relatively inexpensive and already have a fixative, much like under glazes do. You can get a pretty good variety of effects, especially on different brown and red clay bodies. There is a huge spectrum to choose from if you get own oxides and mix them. I will be blending some various iron oxides for my next firing of Stone Age pots.
I have to install a kiln vent as soon as I can and I recommend anyone using oxides should vent their kiln. In the interum, I open the door and have a fan blowing out the door. This helps preserve your lungs but only a vent helps presrve your kiln elements.

 

[penumbra]

I'm about to order some black myself.

I use manganese for black. You can also use black underglaze or mason stains with minimal out gassing compared to that of oxide stains.

 

[mwar15]

Thanks for the info.

the kilns are vented.

I have been using a “pigment” from Georgies, it is very similar to BIO, but expensive. This is why I was looking at BIO and YIO because it’s in the studio already.

I know very little about mixing glazes and components. That said, if I wanted the YIO to keep that yellow what would I add to keep it that yellow? Or just find a yellow under glaze and don’t waist my time?

thanks

 

[penumbra]

That said, if I wanted the YIO to keep that yellow what would I add to keep it that yellow? Or just find a yellow under glaze and don’t waist my time?

I am not sure that question can be comfortably answered. The YIO will probably hold up fine on its on though it may, and likely will change over time. As I suggested, most studio potters use a little fixative.
Of course there are always a lot of variables with oxides and that is why they work well for my kind of work. Its kind of like raku, you can guide it in the general direction you have in mind, and then let it do its own thing. For consistency from piece to piece, an under glaze or a mason stain is the way to go. That is because they are much less chemically reactive if reactive at all. Under glazes and mason stains are made from glazes that are finished fired and then ground into a fine powder which is easily mixed into water or other glaze bodies.
I knew a potter some years back who used nothing but clear stains in either glossy or satin, that he used as a base to mix stains in to achieve colors he wished for. This often requires an opacifier like tin or zinc to make a glaze non translucent. Of course you could mix the stains into a white glaze and forego the opacifier.
IMHO, you are doing what you need to do ......... experimenting.

 

[NaoTK]

Thanks for the info.

the kilns are vented.

I have been using a “pigment” from Georgies, it is very similar to BIO, but expensive. This is why I was looking at BIO and YIO because it’s in the studio already.

I know very little about mixing glazes and components. That said, if I wanted the YIO to keep that yellow what would I add to keep it that yellow? Or just find a yellow under glaze and don’t waist my time?

thanks

It certainly will not stay yellow at all, its just iron as soon as the hydrogens and oxygens burn off. If you want yellow then mason stains are the way to go.

 

[mwar15]

Thanks for the info
@penumbra i sent you. PM

 

[mwar15]

As anticipated….

 

[HorseloverFat]

I was gonna say,

It won’t stay yellow.. iron goes brown and red (when JUST ferrous oxide not in combinations) ...but it looks like you’ve figured that out.

Some of the more crude ferrous oxides I have synthesized/extracted are REEEAL touchy...

Like 3 percent (Of ONE of the batches) was enough to show the reds.. But 8-10 percent was BROWN.

Copper is fun, too. I’ve also got some melted chrome globules I’m soon to start messing with.

I’m in the process of figuring a correct balance of heat/acid for nickel extraction...

All that said..

I recommend NOT doing the things I do.

 

[HorseloverFat]

I use manganese for black. You can also use black underglaze or mason stains with minimal out gassing compared to that of oxide stains.

I was gonna say this, too! About manganese for black!

Everyone beat me here...

..I’m going HOME.

 

[penumbra]

I recommend NOT doing the things I do.

Wouldn't dream of it.

 

[mwar15]

I’m going to order some mason stains

 

[penumbra]

I love it that there are so many potters on this site.

 

[mwar15]

This is a 14x11x4 that is straight RIO sprayed. I love the color and fake patina look. It’s tough to beat

 

[HorseloverFat]

This is a 14x11x4 that is straight RIO sprayed. I love the color and fake patina look. It’s tough to beat


View attachment 409678

Love that “degradation”!