So with that thought setting the stage, you can now imagine how my week is going as I get ready for my two favourite 'Christmas Craft Fairs', both of which happen on the same weekend .... this weekend ... yeah, no, I couldn't keep it simple and just pick one. Since last Fri I've done a bisque fire, glazed everything including several pots leftover from Aug's production run, completed one glaze fire and am now in the middle of my second glaze fire. I've mock set up and divvied up the shelving and only have a ton of little details (times two), to take care of before heading out to do set up tomorrow eve with my sister cousin, Laura, who is going to booth sit at one of the venues for me ... I am smart enough to know I can't be in two places at one time :))
OK ... enough with the whining .... I did get some sweet pots out of the first glaze fire.
Now for the bitch ... the transparent glaze you see is from John Britt's great new book - The Complete Guide to Mid-Range Glazes. The two colours shown here are called Campana Green and Grey, attributed to Jeff Campana. I just love, love, love the silky, buttery feeling of this glaze and fabulous way it puddles and pools without running off the pot. It checked all the boxes at testing time but I did hit a snag in production. Spodumene! .... do you guys know about ol' Spod? I've encountered this problem before with a glaze that's been around for a long while, that also uses Spod, called Nutmeg. When you mix the glaze it looks like you dumped dish soap in it ... you get bubbly froth that becomes popped bubbly froth on the pot and then ultimately, lovely (not!) bubbly pinholes on the finished pot. When I did my Campana glaze tests, it didn't happen. Huh!, I thought, maybe 'they' fixed ol' Spod. However, when it came time to make a production sized bucket, I had to buy a new bag of Spodumene. For pottery neophytes reading this, glaze (and clay) materials have varying sources (the many 'theys' I referred to previously) - different countries, different mines within countries. Normally it's not a huge deal. However, it turns out Spodumene is one of those materials where source does matter. My new bag of Spod brought back the old problem ... bubbly froth. I found the solution on Digitalfire .... wash and dry the Spod .... or from another source .... let the glaze sit, take off water and replace water over time .... neither of which I had time for right now .... and to be honest, both solutions just piss me off. Really!? ... isn't this a quality assurance issue ... shouldn't the product at least come with the warning 'wash me first'! I ended up going with a Marcia Selsor suggestion I found on Ceramic Arts Daily forums. It's what I did previously with Nutmeg ... spritz the bubbled glaze surface with isopropanol (rubbing alcohol). It sorta does the trick but in a newly mixed glaze doesn't help with the bubbles lurking under the glaze surface .... long (sorry, too long) story short, I dipped the pots quicker than I normally would to avoid too many below surface bubbles, resulting in too thin glaze application over textured areas on some of the pots. They feel a bit rough so I am debating re-glazing but that in itself has issues, especially with B-Mix, which is the white clay I use .... oops!, there I go ... bitchin' again ;>)
Now that I've got all my crankies out, I'll get on with the day :>))
Ok best blog post ever! I have been have spasms over spodumene at school! What a foamy mess! The stuff we have at school is very powdery so I am thinking it might be Tanko or Foote….. it's that old. I was ready to toss in the towel when the test tile came out of the kiln! It was beautiful and exactly what I was looking for, stoney matt, waxy, white, breaks on the edges. Fast forward to my studio and I have sparkly spodumene from Australia. I haven't mixed the test yet but will let you know …… what a pain! Hey the pots look great!! Hope you have your feet up and recovering :)
ReplyDeleteMy new Spodumene is a lovely sparkly white as well. If I remember correctly, the old stuff I used in the tests was powdery grey (given to me). I am going to wash the whole works of what's left of the new to see if that makes a difference next time. And you are right .... the results can make it all worth it! Feet have been up for a two days ... that's all that's allowed :)
ReplyDeleteHi Brenda.. I sent you an email via your website re: this post on spodumene..did you get it?? Have a wonderful Christmas.. Cheers, Trish
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