Quick Question: Progressing From Test Glaze Batches To Production Batches

[Joseph Fireborn]

I haven't made the big batch yet. I made a small batch of the big batch ingredients to test to make sure before I made a big batch. I am going to run a few different test.

 

1. zirco and no tin. 

2. no red iron

3. lower tin and 3x the zirco based on the tin i removed. 

4. red iron from the previous batch i mixed.

[Min]

I wouldn't triple the replaced tin with zirco, try just doubling it. 

 

I used a glaze years ago that I couldn't get rid of the speckles in for the life of me. I landed up ball milling it and zero speckles left. (it has zircopax in it for the opacifier) I took the picture of the edge of the pot where the glaze is thinner and it does break a bit but not that lovely rusty colour you can get with tin.

 

 

[Joseph Fireborn]

That is very lovely. I dont mind some speckles. I actually enjoyed the slight speckling and rusty brown hues and highlights. I however do not want 100% speckles on the entire pot, so if I can get that under control and get the glaze slightly more white I will be happy.

[Joseph Fireborn]

Here is an example of the previous glaze and it breaking over rims and having slight speckling. I absolutely adore this part of the glaze. 

 

[Joseph Fireborn]

Okay: Here is the updated test tiles I just took out of the kiln this morning.

 

Just for the record: Johns recipe has 13 TinO as the base for folk art white. I was just testing differences.

 

From left(1) to right(7).

 

1. 7 TinO, New RIO

2. 13 TinO, New RIO

3. 7 TinO, 0 RIO

4. 0 TinO, 14 Zircopax, Original RIO

5. 5 TinO, New RIO, 4 Zircopax

6. 13 TinO, Original RIO

7. 13 TinO, New RIO, 1 Cobalt Oxide

 

 

None of them look particularly like the Folk Art White in John Britts book. Number 3 is probably the closest, however it doesn't have the nice iron breaks. The look I have been going for is number 6, which is the glaze I have been using. If has little speckles here and there nothing like 1 and 2. I am still not sure why the new iron adds so much speckles. Number 2 and Number 6 are identical in recipe except for the different iron oxides from different suppliers.

 

On axners website they only offer 2 RIO, spanish and normal. On US pigments they offer several: natural, spanish, pink, and high purity. I ordered natural. I am assuming maybe I should have ordered high purity.  Either way I enjoyed the testing. 

 

One of the interesting things I found here is that tile 2 and tile 6 have the same amount of tin, however tile 2 is much whiter than tile 6. But tile 2 has the more speckly iron oxide while tile 6 has the less speckly? .. not sure if speckly is a word.

[neilestrick]

I think your new iron isn't ground as fine, and therefore is staying speckly rather than going into the melt. Or possibly there's some other impurities in there that need to be screened out. Did you screen the test batches or blend them?

[Joseph Fireborn]

I used a screen, but it is just a 80 mesh screen. It caught nothing, poured through like liquid. I guess I need to get a tighter screen.

 

I think you are right about the fineness of the grind though. The other iron is much less clumpy.

[neilestrick]

Usually an 80 will do the job, but every now and then you'll get an oddball. I remember when I worked for a commercial glaze supplier there were a couple of mason stains that we had to screen at 150-180 to keep them from speckling. It took forever to get everything through the screen. It may be that with other glazes it's not an issue, though. Test it in another glaze that you use iron in and see how it works.

[High Bridge Pottery]

Number 6 looks quite close from this side, hard to tell. Still not that white. Interesting to see the difference between the two.

[oldlady]

can you ask the supplier what size the iron is?

[Joseph Fireborn]

@HBP, yes number 6 is what I have been making all along. It is way more yellow than white though. But it breaks really nice over rims and with finger marks.

@oldlady, I am sure I can. I will ask next time I contact them.

[TJR]

 

I like base 10.

 

Just me who uses a base 12 number system?

 

I never managed to gradually up my glaze size, maybe that is why me and my glazes fell out.

 

The reason for base 10 is that you are working in percentages. your glaze should add up to 100 grams. 10% zircopax will be added to the total to make a white glaze.

For example

Blah   20

blah   20

bla bla 20

ba       20

bash   20

-----------

       100

       10 zircopax

This gives you a white glaze.

Zero point 5 cobalt carb. gives you a blue etc [0.5]or one half a percent.

 

TJR.

[Joseph Fireborn]

So what containers are people using for a glaze they don't need a ton of, but still want to dip a mug in. Like I know I want a 10 gal bucket about 3/4 of the way full with one glaze, but I want a few other glazes and I want to be able to dip bowl rims, or mugs in etc. 

 

I have been looking through amazon, but I haven't found anything besides the 1gal pails. So a 3.7K gram = a gallon, so I assume something like 1.5K Gram with 1.5K ml water will fill up a gallon pail, and leave room for displacement. Id have to test, but I presume its close. I have several glazes I would like to have 1 gallon of. Just not sure what to put them in for a variety of shapes, mostly mugs and cereal bowls.

 

What type of container do you use for that? I was thinking 1 gallon pail with a lid, but I figured there might be better shapes for mugs that are taller? Any recommendations that you have found better than the 1 gallon pail?

[bciskepottery]

Margarine containers/tubs work well for small batches; great for dipping rims of mugs and small bowls. Also, I get 2 gal buckets from Home Depot.

[Joseph Fireborn]

That is an interesting idea. I will have to find someone who eats margarine.

[oldlady]

if you are in a part of georgia near a large city, try looking for containers in restaurant supply houses. not the thin, clear ones but the heavier plastic tubs used by carryout  chinese restaurants.  they are excellent for many things.  restaurant supply stores sell sleeves of 25 or 50 containers of the same size and a sleeve of tops.  these are usually under $5 per sleeve, last for years and are not visually distracting like used plastic tubs with labels on them.  store smaller amounts of colorants, dry ingredients, etc in them.  do not keep your chemicals in paper or plastic bags, use solid containers.  dipping amounts out of solid containers is less messy and safer than floppy bags of any kind.

 

the half pint size is great for glaze testing, and writing with a sharpie what is inside on both the lid and the container will keep you organized.  changing the label is easy with a can of hair spray and a cotton ball. (acetone does not remove sharpie ink.)

 

thrift shops sell old tupperware containers in all sizes and shapes.  cake covers are great if you want to dip something wide and flat and there are tall ones for spaghetti and stuff to dip tall mugs and vases.  NEVER pass up a tupperware  (look for the originals) container unless you are totally broke.

[Joseph Fireborn]

Does anyone have any experience glazing with a sprayer. I know the Stephan Hill people do it, but i was thinking, it really is the most logical way to use a lot of glazes without having to have massive amounts of them. Maybe that is the route I should go down instead of trying to make batches for what I will need etc. Although it will take longer than dipping I bet. However I bet it is nice for using small amounts on the highlights I want. I imagine it will also let me have small batches of glazes that I can use on larger pieces without having to have massive space taken up in my half garage studio.

[oldlady]

yes, to almost all of that.  but it is much faster than dipping and less mess spread around.  concentrated mess is easier.    like anything, it takes practice to get the right thickness for each glaze.  if you try it, DO NOT WATER DOWN YOUR GLAZE.  look at the eze sprayer, it is not perfect, but it is easy to fix and clean to use.  it holds a pint, enough for several things before needing a refill.

 

just a question about your batches of glaze.  are you making a base glaze or are you trying to vary every ingredient for some reason?  one nice big batch of base left dry in a bucket allows for lots of adjustments by scooping out a small amount and adding some tiny amount of some ingredient to test that theory.  when you are done, and find exactly what you want to change, weigh the rest of the dry batch and do the math to correct it all at once.

[Joseph Fireborn]

Old Lady, thanks for all the great advice. I am kinda in a stuck place. I have a ton of pots that I want to decorate and glaze. However I am having trouble finding a base glaze I want to use on all my pots. A part of me wants to use a stark white on the rims and inside of my pots that I know is food safe highly glossy and I have tested it as they do in mastering6. Then the other part of me wants to use crazy glazes on the bottom or outsides of my pots. I even want to layer some under the white in hopes that it will run all sorts of odd colors. I still have a lot of testing to do for my look, however the issue is I dont have a ton of space for buckets and I also dont have a lot of liquid $$ for making batches big enough to dip bowls in. I am still just a hobby potter right now. My forms are good enough to sell, looking at other successful potters and holding their stuff at craft fairs around my area. The problem I have is glazes. I can't find a glaze aesthetic that I like and I am happy with using on a majority of my pots. My forms are nice, but my glazes are boring. I like such plain colors, I dont like the bright blues or purples or greens. So I am left with like, blacks, whites, greys, browns, creams. I dont mind a splash of color here and there.

 

So I was thinking if I got into spraying I could spray my pots, then dip them in my liner glaze and have a nice run.

 

Sorta something like this is what I am going for.

 

http://noelbaileyceramics.com/wp-content/gallery/current/nsb027.jpg- work of Noel Bailey.

 

 But a little less dramatic on the form, and I am more interested in mattes on the bottom half of my pots for texture and feel.

[oldlady]

you have picked a worthy goal.  however, noel bailey's website says he fires his PORCELAIN TO CONE 10.  you will not be able to exactly duplicate this even if you work on it for ten years unless you use his porcelain, his glazes, his kiln.  

 

try finding someone who works in a similar manner at the temperature you can duplicate.  

 

people have shot countless arrows at the moon but not reached it.  why spend a quiver full of arrows in a fruitless quest?

[Joseph Fireborn]

I don't mean to replicate his work at all. I just googled white cups and found his as an example of the white on the top and the colors on the bottom. I don't want to duplicate anyone at all really, just find my own little area. I realize that its pretty hard to come up with anything original, and that's fine, as long as the idea was originally from my brain and not from a picture I thought over forever.

 

Thanks for looking out for me though.   Would be funny trying to get those results in an electric kiln at cone 6.

[Joseph Fireborn]

Well, I bought the Stephen hill video download about spraying and his glazes and stuff. Spraying seems great for what I want to do. It allows you to carefully put on the textures and stuff I want on my pots and also I might even enjoy single firing. The only issue is the spray booth. I would have to build one in my small shed behind my house. Which means I would have to carry pots about 30-40 yards to my shed to glaze them, then back to my kiln. I can imagine the accidents happening between here and there. I dont know, maybe I am over thinking it.

 

I could turn my shed into my glazing shed. I just don't know if its worth the effort to move to that. Oh Pottery.  Then there are the neighbors. Man being a potter in the city is a real pain in the butt.

[Joseph Fireborn]

Thanks to HighBridge for this wonderful white. Abandoning Folk Art for this beautiful glaze! Plus it doesn't have tin in it, so its hella cheaper.

 

[oldlady]

somewhere in the ceramics monthly archives from a very long time ago, there is a set of plans for a spray booth with a waterfall that keeps the dust down.  it was by Bill Campbell.  very simple, just a waterproof space with a drain, a pump, and perforated pipes running around the top of the inside walls.  a fan is in there somewhere.

 

Del Martin built one into a corner of his spotless studio in maryland.  he stands behind a rubberized curtain and sprays all his work.

[Joseph Fireborn]

http://www.tomturnerporcelain.com/page031.htmThere are the plans. I looked at it extensively. The issue is I don't have a place to vent the booth or I would spray in a heartbeat. Maybe when I get some more money coming in I will build it in my shed out behind my house. It is just a little potting shed but I could definitely build it there I think. I could pump the air into the trees behind my house which is about 200 ft from my neighbors house so between the hepa filter and the trees I doubt anyone would have any issues. Maybe next year!

 

Thanks for the plans I googled them and found it right away. Neat stuff. I think my next thing is going to be running water in my studio. Going to just buy a laundry sink and tap into the faucet that runs to my outside spicket. Put a 5 gallon bucket under the sink and when it fills just empty it. No need for plumping or a clay trap. Better than what I doing right now, which is going outside to use the water hose for everything I need to rinse off.