the glaze test

I've unloaded the kiln and am mostly happy with my test results.  This is glaze one, which was totally new to me.  Um, No.  I'm not sure if you can see that it has an almost eggshell like texture to it- almost miniature dimples.  It is bright white and runs all over the place on the pieces that I dipped.  I tried it on one of my botanical mugs and you can't see the leaf at all.  It was fine for brushing, but again, the piece that I brushed had a 4-leaf clover in the middle and the image was almost completely obscured.  The glaze also dripped all the way down to the kiln shelf on several pieces, so I have some shelf maintenance to do now- you can see this on the little bowl, which had a really clear margin of wax on the bottom to keep the glaze off the bottom of the pot.  This will probably be a good liner glaze (to go on the inside of mugs, particularly the mugs that I draw on), but this glaze is not for me.  I bought 5 lbs of it, which makes a gallon, and it should be fairly easy to use up if I use it exclusively on the inside of pieces.

Here are glazes 2 and 3.  Glaze 2 is my old glaze.  Glaze 3 is my old glaze, just a fresher batch.  Again, I dipped and brushed pieces.  I measured 100 ml of each glaze and then weighed them.  They each came in at 146 g, 145-150 being the optimal weight according to the manufacturer (less weight means too much water, more weight means too much glaze solids).   No shivering off this time with the old glaze, but there were still patchy rough places.  In this photo I dipped the platter on the bottom in the new formula and it was almost perfect.  Lesson 1- start dipping ALL of my pieces if possible.  The second piece, on top, is the new mix of white on top- nice and thick, 3 brushed-on coats.  On the bottom, the old mix- again, 3 brushed-on coats.  I'm not sure if you can tell in the photo, but the top layer is much thicker than the bottom layer.  The really interesting thing about these tests is when I mixed up the  glazes, there was a discernible difference between the two buckets of the old and new glaze.  The old glaze was bright white and settled out quickly, even though I'd added a stabilizer.  The new glaze was creamier, almost beige.  It didn't need a stabilizer, even after I'd been using the bucket for an hour or so.

I didn't glaze under ideal conditions- it was raining cats and dogs for most of Tuesday morning, and I was in the even-more humid basement.  I always have problems with the glaze sticking on humid days, so I expected some problems.  I'm pleased that I didn't ruin too many pieces with Glaze 1, that 75% of the pieces I used Glaze 3 with came out near-perfect, and Glaze 2 did exactly what I expected it to, which was to under-perform. 

If you're interested in knowing which glaze I used for Glaze 1, shoot me an email (I don't get most of the email addresses with your comments) and I'll tell you.  Glaze 2 is an at least 3 year old 25 lb bag of Opulence Gloss White.  Glaze 3 was a brand-new bag of the same.  There is one other white glaze I'd like to test, but since I buy all of my clay and most of my other glazes from Opulence (they're based in Nashville, fairly close to me), I think I'll stick with them.  Now to work on those dinner and wholesale orders!

I'll be at MFM for Mothers' Day shopping on Saturday.  Maybe in the new section of the pavilion.  Come say hello!