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First Time Mixing Glaze


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I had the husband pick up two 5 pound bags of glaze mix the last time he was in Tacoma. One is a clear and the other is a white, both are glossy ^4-6.....

 

I have a couple of questions as to how to proceed. Supposedly, these should make 3 quarts of glaze each. I have nice new two gallon buckets with lids, so I'm all set in the storage department. In talking to the fine folks at Clay Art Center, they said to use one quart plus one pint of water to start with. Their instructions are to put the water in the bucket first, then pour the glaze mix in on top of that and let it sit over night before stirring it up. They further instructed me to screen it with about an 80 mesh screen after I've stirred it up.

 

Well, here comes the problem. I don't have an 80 mesh screen or any other mesh size for that matter! <_<

 

Just how critical is it to screen this stuff prior to use? The glaze guy and I did talk a bit about making a home made screen from the fiberglass door/window screen material.....What do y'all think about that?

 

My second question regards quality of water: Ours is pretty heavy in iron and magnesium. Should I use filtered water, or maybe even distilled? Or would I be going to extremes with that?

 

I'm probably just stressing out unnecessarily over this, but I want to do it right. We're on a limited budget around here, and I really don't care to roach an entire bucket of glaze because I took the wrong shortcut. Your thoughts are greatly appreciated by this newb! ;)

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I would get some 80 mesh and make a sieve or buy one. It is important or you could end up with grit on the glaze surface. It is a necessary tool for mixing glazes. Second, follow their directions to start with less water and let it sit overnight. You can always add water more easily than removing it. Use distilled water if your local water has a lot of minerals.

 

Marcia

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Thank you Marcia! I appreciate the input. So.....plain old window/door screen won't be small enough? Nuts! I was really hoping I could slide by on that one. I'll have to wait the better part of two weeks before I can get around to picking up a proper screen. <_<

 

We have a filter on one of the sinks in the kitchen for drinking water. Do you think that would be sufficiently clean, or would distilled really be the better way to go?

 

Does it matter how long after I've mixed it up before I screen it. I mean, should it be screened the very next day? Or can I let it sit for a couple of weeks? I have to go over to Tacoma [279 miles away] next week and will be there for about a week. I could pick up a good screen then. Will anything adverse happen to the glaze after that long sitting in the bucket?

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I mail order a lot of materials because I am so far from any supplier. 280 one way to San Antonio. Check on eBay for brass mesh. I recently posted how to make a sieve with a 5 gal. bucket lid. Remove the cord from the lid, cut a hole in the lid, stretch the screen over the rim od the lid and re-insert the cord to hold the screen. there is a 12" copper screen on eBay with free shipping for $12.95. That is cheaper than gas to tacoma.

 

 

 

Marcia

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Thank you! Thank you! Thank you!!! Big hug and a kiss to you Marcia!!! I'll try to find that on Ebay! And I just happen to have the kind of bucket lid you speak of. I knew there was was a reason I held on to all of those drywall mud buckets after we finished building the house! :D

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Does anyone know what sort of mesh a permanent cone coffee filter is?  I picked one up for a dollar or so, thinking I might use it on small test runs of glaze.  Can't find any information on the mesh size on google.  Like this:coffee_filter.jpg .

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Whooopeeee!!! It must be my lucky day! Denny had to make a run into Cheney [15 miles east of us] for some plumbing parts and just guess what they had in stock! Yup! 80 mesh metal screen material. OK, so it's not brass, but I'm hoping it will do. I'll know for sure on the first piece I put through a glaze firing, huh? I figure it's worth a try at the very least. Now to go cut the living shinola out of my bucket lid. I only have about three dozen of the dang things sitting around, collecting dust. :D

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Just got John Britt's cone 6 book. He says a couple of interesting things. If I have it right mixing the ingredients REALLY affects the way the glaze takes. Particle size is much finer because suppliers are more efficient .here is my favorite: if mixing ingredients that don't mix in water easily, mix all the dry ingredients into a 5 gallon tub , close it up , roll it around to mix. LET THE DUST SETTLE! Pour over water that is in another 5 gallon tub( good thing you have so many) use less water than you will need, slake over night, mix and adjust next day. He says to note specific gravity for more acurate glazes. It is a really fun book, well worth the money for the photos alone, no less the recipes.

He says to sieve , but doesn't say why it is so important. He did talk about particle size for dry material. Any takers? I love to know...

Jolie

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besides mixing all the ingredients very thoroughly, sieving removes the body parts of the dead bugs that  crawled into the containers that did not seal well.  don't worry, they could not crawl out and just died quietly.

 

sieve at least 4 times.  each time it gets easier, at the last transfer from the mixing bucket to the storage bucket, clean both buckets with a kitchen rubber spatula.  wash the sieve and discard the grit that is left.  yes, there will be a little of it.  do not worry about those few grains of whatever.  they will not affect the measurements you have so carefully made.

 

water contains various chemicals in different parts of the country.  i always use distilled water, it is less than $1 a gallon and why do all that other stuff and just use tap water?  (this is where that commercial about you being worth it comes in)

 

label the bucket and its lid!  right away!  sharpies work well on plastic buckets and can be removed with hairspray.

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I use tap water to mix, but our municipal supply is quite good. I think filtered would be sufficient, as long as the manganese and iron are out. Those are two things that actually would affect a glaze. Rainwater is sometimes used.

I wouldn't mess around with dry mixing. Too much dust. Sieving distributes the particles quite evenly, especially if you do it a couple of times. I sieve twice, but otherwise follow the same procedure as oldlady.

Weighing out and leaving your glaze in part of the water for a while (or a few days) sure won't hurt it. I actually find it easier to mix and get the lumps out if I let it slake in part of the water for a few hours.

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Amy, remember to go less than the 68 ounces at first. That is 8.5 cups, I would probably go 6 - 7 cups water. When you think you have the right mix, do a specific gravity of the glaze.

 

This was taken from another posting on the subject of Specific Gravity. I believe Mea said this..

 

To measure glaze slurry, getting the right specific gravity for each glaze you use is a good idea until you get to know the glaze well enough to not measure it. Keep the bisque firing the same so it's the same porosity.

 

Put a clear cup on your scale and add water to exactly 100 grams, if you have a graduated cylinder use it instead. Mark a line on the cup where the water comes to and dump it out and thoroughly dry the cup. Now add your glaze slurry up to the line and weigh it. Take this figure and move the decimal 2 positions to the left and that's your specific gravity. Each glaze will have it's own s.g. The idea is to get the s.g. right before each glazing session and dip for the same amount of time so you are laying down the correct amount of glaze thickness.

 

This is another tidbit about the water in a glaze...

 

Rule of thumb is 2 oz per gallon - either removing or adding. Also, keep any water removed separate, in case you need to add water back.

 

Good Luck!!

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Gawds! I LOVE you people!! So much help, my cup runneth over! :lol:  [yes, the pun was intended!]

 

Guinea, don't be the least bit surprised if I give you a call today!

 

I just checked the two glazes this morning. I had put in 48 ounces of filtered water yesterday and they definitely need more. They're about the consistency of pancake batter right now.

 

And now I see that I'm going to need to invest in a gram scale!?! Am I to understand that not all glazes have the same specific gravity? Oh yippee!

 

Why do I always pick the hobbies that require tons of expensive equipment? And I thought getting into quilt making was pricey! :blink:

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I am going to be doing my own glaze testing as well, as I just bought some small sizes of the various chemicals to mix.  I used an Ohaus triple beam balance scale in a class I took on glaze mixing and I knew they are expensive.  Today I was at a thrift store and picked one up for $15!!!!!!  I brought it home and tested to be sure it is still accurate, and it seems to be weighing correctly. I was leery of paying over $200 for a brand new scale so I feel it was so serendipitous to find a used one.  

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For the consistency of the glaze, at work, we use that kind of cylinder with a tiny hole at the bottom and we count how many seconds it take to empty. We know the right consistency is between 19 and 22 seconds. If it takes longer, we just add water and mix again.
But maybe it is not precise enough for what you want to do.
That is the thing we use: Viscosity Cup

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I finished mixing the glazes up this afternoon, and so far, they look pretty near identical to what we have down at the community studio. I'll do a test firing to see how many brushed coats will look best, along with one test tile of dipped for each glaze. Each 5 pound batch made roughly 3 quarts of wet glaze, so, unless it's a small piece, I don't see myself doing a lot of dip glazing......

 

Which brings me to my next question:

 

At a later date, can I mix up another 5 pound dry mix batch of each of these glazes, just as I did this time around, and then add them to their respective buckets? Or is that a cardinal sin? :huh:

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