This time the mad scientist really messed up. The copper carbonate turned black, really black. Who wants a black xmas tree? Not sure what will happen if I put a clear glaze over them. I also have lots of black stars, actually they're really dark green and black, from deep in the cosmos I guess. I do have a few nice yellow stars, the ocher worked nicely.
The cobalt and copper carbonate aren't bad on the piece above but it seems I've transferred finger prints of cobalt to the fronts and backs of many of the other pieces I loaded in the bisque.
Like the back of this rooster platter. and the inside of several bowls and the reverse side of several bowls. It might have been a design element but they are too random to look good. It seems that the oxides also stained my kiln shelves. Even after firing I am still getting cobalt finger prints every where. Perhaps some frit added to the stains would alleviate that transferring after firing?
Just yesterday I read on Midori's blog where she puts deep sand on her shelves to protect them from oxides. Too bad I learned that trick after the fact. It also would have helped if I had loaded the pieces with oxide and then washed my hands before loading the other pieces. Is there anything I can do to get the oxides off the pieces? And how to clean the shelves. Probably sand them? And I have a glaze load I wanted to fire.
On top of that I hurt my knee the other day, (I think it's the lateral collateral ligament) and have to walk stiff legged on that leg which means it takes me three times as long to walk anywhere or go up and down the stairs. Then yesterday I developed a tooth ache in my lower front teeth. Actually it's feels like the gum. I read a bumper sticker that said old age isn't for sissies and I'm not even old yet. Heaven help me. Thanks for reading and for all your comments.
it is a pain, I don't think you can do much to rid yourself of the stains. Sanding, maybe?
ReplyDeleteHi Meredith, thanks, I'll try sanding and then I'll glaze over the ones in the bowls but the bottoms of the platters, we'll see if they come off but I bet the cobalt is embedded deeper in the clay.
ReplyDeleteYou may have luck with the copper carb when you glaze with the clear or a white glaze. However, and I'm sure you've already had this experience- it can take on a gunmetal color where it is heaviest.
ReplyDeleteAlways a learning experience. That's what I tell myself when something frustrating happens.
Hi Melissa, thanks, I was going to try the clear but I like your advice of trying the white and see what happens, better a white tree than a black one. Ha.
ReplyDeleteI was able to sand a couple spots of blue slip off of bisque fire pots before, so definitely give it a try.
ReplyDeleteI use a Dremel or grinder, once it's fired...but if it's only bisqued, then it is still pretty soft clay, so sanding sounds possible, especially on flat surfaces. Sorry the copper was the black, but it does turn green under a white glaze, not exactly Christmas tree green though. Try it.
ReplyDeleteHi Michele, thanks, I'll try the sanding.
ReplyDeleteHi Barbara, thanks, I'll try the white glaze.
How very, very frustrating.
ReplyDeleteAnd I hope your knee recovers quickly.
Hi Sue, thanks, knee is slowly getting better and I hope I can fix most of the pieces that got the stains on them.
ReplyDeleteSorry to read about the knee injury and hope it heals quickly.., life isn't much fun sometimes.
ReplyDeleteI am an expert at getting oxide prints onto things too. As some of the others have said, sanding might get rid of it. I have also had black from copper under glaze turn green when a clear glaze is put over it, so you might find that it gets better with a glaze. Anyway, good luck, and hope you are better soon.
Hi Peter, thanks, I sanded the back of the plate last night and was able to get it off, thank goodness, I may try firing with transparent glaze and see what happens, next I'll try sanding the bowls, they have cobalt on the inside and out side ugh.
ReplyDeleteFunny thing about the knee I don't even know how I injured it, same thing with my shoulder rotator cuff, don't know how I did it.