help with cerium oxide polishing

[LisaBartlett]

This is the first time I have tried to polish with cerium oxide. My kiln wash left some ugly spots when slumping and so I did not want to re-fire to polish. I thought I would try by hand.

I am using a dremel with a felt pad. I let it "charge" overnight. Then I used a fairly wet paste of the cerium oxide and water. All I achieve is a non-glossy surface with the cerium ground in in some places.

What am I doing wrong?

[Brian and Jenny Blanthorn]

This is the first time I have tried to polish with cerium oxide. My kiln wash left some ugly spots when slumping and so I did not want to re-fire to polish. I thought I would try by hand.

I am using a dremel with a felt pad. I let it "charge" overnight. Then I used a fairly wet paste of the cerium oxide and water. All I achieve is a non-glossy surface with the cerium ground in in some places.

What am I doing wrong?

Cerium is a finishing powder

U need a good surface first

Usually pumace

There is a lot in the archives on this

Probably some totorial or somthing on the site

Brian

[Brock]

This is the first time I have tried to polish with cerium oxide. My kiln wash left some ugly spots when slumping and so I did not want to re-fire to polish. I thought I would try by hand.

You didn't see these ugly spots when you fused the piece?

They appeared in the slump firing?

I am using a dremel with a felt pad. I let it "charge" overnight. Then I used a fairly wet paste of the cerium oxide and water. All I achieve is a non-glossy surface with the cerium ground in in some places.

What am I doing wrong?

[LisaBartlett]

Brock,

Yes - ugly spots were not there when I fused. They appeared with the slump. Only did this on two of six rice bowls I did. Stange looking. Fairly smooth but very whitish. Devit? And if so, wouldn't the cerium work without the pumice?

[Brock]

Brock,

Yes - ugly spots were not there when I fused. They appeared with the slump. Only did this on two of six rice bowls I did. Stange looking. Fairly smooth but very whitish. Devit? And if so, wouldn't the cerium work without the pumice?

You should not get devit on a slump firing. How hot was your slump? Devit is not usually white, more of a dirty transparent. Cerium will work without Pumice, but it'll be a LONG process. Brock

[LisaBartlett]

Yes - I wasn't thinking. Can't be devit.

So - perhaps it's my patience that is lacking. I am not polishing long enough?

Any other solutions? Re-fire over the mold? The mold is steel with kiln wash. Would that be a cause?

[Brock]

Yes - I wasn't thinking. Can't be devit.

So - perhaps it's my patience that is lacking. I am not polishing long enough?

Any other solutions? Re-fire over the mold? The mold is steel with kiln wash. Would that be a cause?

If you are firing bowls OVER a mold, that is probably the source of your problem. The surface contacting the mold will almost always pick up some texture, and when you slump OVER, that surface will be the interior, (viewing) surface of your bowl. Try slumping INTO your mold. Brock

[LisaBartlett]

unfortunately - it is a steel mold and I had a terrible time slumping into it. But I will try again. I really don't mind the texture so much as the discoloration. I suppose the one is causing the other however.

[Brock]

unfortunately - it is a steel mold and I had a terrible time slumping into it. But I will try again. I really don't mind the texture so much as the discoloration. I suppose the one is causing the other however.

Slumping into steel molds is relatively easy. Do you have any finishing/grinding equipment besides your dremel? If you do, put a small bevel om the back of your piece, by grinding/removing the 90 degree angle between the side and the bottom. This bevel can be as small as 1/16" and will facilitate the blank slumping down the mold. Brock

[LisaBartlett]

yes i have grinding equip. will try. thank you.