07 November 2009

interesting, in an annoying way

these photos are poorly lit, and strangely colored (that's me reflected in a tumbled surface). but never mind that...

look at the size difference. they were exactly the same size before firing (at 1110 for 45 minutes). the difference was that one of each pair (the small ones) has my little logo in silver on the back. i fired those on vermiculite so the earring wouldn't drape over the thickness of the logo. the other(plain) ones i fired flat on the kiln shelf. apparently, the drag on the kiln shelf keeps them from shrinking as much. since this picture was taken, i have since fired the larger ones to 1650 for 10 minutes (not much change) and to 1110 for 45 minutes, resting on the vermiculite. they're quite a bit closer in size now. you can be sure i will choose 1 common surface to fire on in the future....
this pair is even worse. after all the extra firing, i'm going to have to SAW some of the top edge off.

that brushed surface is so much nicer....
this is my "hope rising" series of earrings. there is a necklace (pic to follow) in the series, too. it was made to donate to an auction to benefit a friend with cancer.

3 comments:

Barb Fernald said...

How strange! I never thought there would be such a difference in shrinkage. Have you fired pieces on a flat surface and had them slump over your logo on the back? How thick is the clay you are rolling out for stamping your logo?
I had a thought about your tumbler issue. How do you store your steel shot? Is there a chance there is rust on it?
xoxo

holly kellogg said...

my logo bits are 2 cards at their thickest and some of the earrings are 2 cards...there's really not a lot od stiffness in 2 cards...after this batch i'll probably move up to 3 and accept whatever slumping comes my way. uuuummmm....store my shot? does "in a big damp heap" answer your question! it certainly answers mine! how am i SUPPOSED to be storing the shot?
xoxo

Barb Fernald said...

Well, that answers the question! You are probably getting a fine film of rust from your shot, on your silver pieces when you are tumbling them. I'm not sure how you can remove it from the shot...um...but if you get new shot, you should probably dry it out completely before storing it. (spread it out on a towel in a single layer)
OR just rinse it when you are done tumbling and put it back in you tumbler, totally covered with water or burnishing liquid. I just use water, then when I am ready to tumble a new batch of stuff I drop it in the tumbler and add a little bit of ivory liquid. I don't know why it works, but keeping it totally covered with water keeps it from rusting.
xoxo