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volumetric glazes?

updated fri 17 dec 99

 

Ray Aldridge on mon 13 dec 99

At 11:22 AM 12/12/99 EST, you wrote:
>----------------------------Original message----------------------------
>Thanks Sylvia,
>
>Makes sense - but a navy base in the desert - somehow that seems strange.
>
>There can be problems useing volume when making glazes - the way material
>gets compressed in bags can make duplicating a glaze difficult - so I do
>recommend you go back to your scale.
>
>RR
>

It struck me that there might be better ways to go Ohaus-less than
attempting to measure ingredients volumetrically.

It's very easy to make a free scale. All you need is a bit of string, a
stick, and a couple of pans (yogurt cups?), and a place to hang the thing
from. You can balance the scale by moving the string that ties to the
middle of the stick a little one way or the other. The only problem is
calibrating the scale. But you can use a baggie with a little sand as an
arbitrary weight, and then make up a bunch of identical weights by using
the scale. Then you can develop your glazes as arbitrary units of weight.
For example, the well-known 5X20 glaze would be very simple to weigh out,
because you just use equal weights of each ingredient (in that case you
wouldn't even need your baggie weights.)

More complex glazes would have to be adapted for the scale. For example, a
glaze that was 60 feldspar, 20 whiting, 20 ball clay would take 3
baggies-worth of spar, and one each of the other ingredients.

And so on. It would be less convenient than a triple beam, it would
discourage you from using fussy glazes (I'm not sure that's a disadvantage)
but it would be vastly more repeatable than the volumetric approach.

You know, I've actually been thinking about making such a scale for
weighing out clay, since my production throwing requires very precise
measurement, and the cheap spring scale I presently use has to be
recalibrated against the triple beam every time I use it. It would be much
simpler to just put, say, a 1 and 1/4 pound counter weight on one side and
weigh out a couple dozen mug eggs. And so on.

Ray


Aldridge Porcelain and Stoneware
http://www.goodpots.com

Fabienne Cassman on tue 14 dec 99

At 03:29 PM 12/13/99 -0500, you wrote:
>middle of the stick a little one way or the other. The only problem is
>calibrating the scale. But you can use a baggie with a little sand as an
>arbitrary weight, and then make up a bunch of identical weights by using
>the scale.

Hello,

If you really wish to know the weight without it being arbitrary, I suppose
you could do the following (of course, we're getting away from volumetric
measuring):

By using an identical container on both sides and using the measuring cup
lurking in your kitchen, you can use the metric system. If I remember this
correctly from kiddie school, 1 liter of water is 1 kilogram (=1000 grams)

Once calibrated, to know the weight of the material, you could pour water
in the counterbalancing container and figure out how many grams you have by
measuring the water with your cup. It would be easy to duplicate weights
that way, too, should one go bad.

All my measuring cup have milliliters on the other side of the ounces (1
liter = 1000 milliliters) It shouldn't be hard to find one. I can't
imagine doing 100 gr test batches with this system though.

Cheers,


--
Faye http://clay.justnet.com

Yes, I have learned from my mistakes...
I can reproduce them exactly.

Craig Martell on wed 15 dec 99

Hi:

Cutting corners with glaze preparation is fine as long as one is willing to
accept the consequences. I have an Ohaus triple beam because I want to
avoid the annoying variable of not compounding my glazes as correctly as I
possibly can. One of the most discussed areas of the craft via Clayart is:
"Why did my glaze screw up?" "Why doesn't my glaze work anymore?" "What
the hell is happening?" Not using a good scale may compound some of the
problems that we all encounter with glazes. I would think that a scale is
well worth the dough you may shell out. I sure as hell wouldn't want to
make glazes without one.

My opinion which may be "round filed" where appropriate.

Craig Martell in Oregon

Ray Aldridge on thu 16 dec 99

At 05:40 PM 12/15/99 EST, you wrote:
>----------------------------Original message----------------------------
>Hi:
>
>Cutting corners with glaze preparation is fine as long as one is willing to
>accept the consequences. I have an Ohaus triple beam because I want to
>avoid the annoying variable of not compounding my glazes as correctly as I
>possibly can. One of the most discussed areas of the craft via Clayart is:
>"Why did my glaze screw up?" "Why doesn't my glaze work anymore?" "What
>the hell is happening?" Not using a good scale may compound some of the
>problems that we all encounter with glazes. I would think that a scale is
>well worth the dough you may shell out. I sure as hell wouldn't want to
>make glazes without one.
>
>

I wouldn't either. You may have missed the original poster's explanation,
which was that she had a triple-beam, but was temporarily separated from it
and still wanted to experiment with glazes.

If you didn't have a scale, and had no money for one, perhaps you'd be
better off buying commercial glazes. But I wouldn't find it as
interesting, personally, and you could glaze a lot more pots with homemade
glazes, which would get you closer to Ohaus ownership faster.

I don't actually think there's anything inherently inaccurate about a
simple homemade scale, using arbitrary weights. The world got along with
this technology for many centuries. You'd have a harder time weighing out
complicated glazes, and weighing small sample glazes would be pretty tough.
Faye's idea of using water as a counterweight sounds like it would work
pretty well, though, even for complicated glazes.

But you're right, I wouldn't want to run a business that way, if I could
avoid it.

Ray

Aldridge Porcelain and Stoneware
http://www.goodpots.com