To grog or not to grog?

I prefer fairly soft grog-free clays. Grog usually just causes grog tears for me, and is more difficult to pull into really thin walls. I don't sponge, anyways, and prefer the nice smooth surfaces I can get with a metal rib.

Although I do miss the nice soft callous-free hands I had when I regularly threw highly-grogged clays.

I spent all of last year working on 2 different clay bodies with vastly different amounts of grog. I worked with flameware (a specially formulated claybody that can be used directly on a stovetop) and with porcelain. The flameware had the most grog of any claybody I've ever worked with. My hands were raw, and felt like glass slivers were imbedded in them.

The porcelain was heaven after that. It's so soft and smooth and grog-free that I wanted to give myself a facial with it :-)

Of course they're entirely different in looks and function. But for throwing purposes only, I prefer the porcelain.

Do you ever try using a rib for your surface instead of a sponge? You might find that you can get a smoother finish that way. The damp sponge is loosening particles because it's wet, then dragging them along the surface. The rib, on the other hand, is compressing everything together. Try different ribs, some softer and more flexible, some metal ones, and some wooden ones. They're all good for different things. My preference is a fairly flexible rubber rib for most things, but sometimes I like a metal one.

Deb R.

That's what I like about the fine-grogged clay I am now using. It is a firm clay, so I have time to work, as it doesn't take on water all that well, and my hands don't feel like I have run them over a sander, no matter how long I have been working at the wheel.

I've only worked with one porcelain clay, but to me it was so plasticky that I really didn't like it, even for hand-building. I couldn't imagine using it on a wheel. But maybe it was just a "bad" clay.

ie. grog free

I do use a rib sometimes, but I find it makes lines, where I want a smooth even surface. Also, ribs don't fit into the little nooks and crannies around the foot of the piece.

I do take your point about the water bringing the grog out, though. I'll try to use the rib more often.

Thanks :-)

Marianne

When I use my flexible rubber rib, I get as smooth a surface as I want--no lines unless I put them there on purpose. Also, it'll bend around curves in the pot just fine. Plus, as far as the foot goes, some of the finish work can be done in trimming later. It doesn't have to be in final form on the wheel. As a matter of fact, you'll get a stronger bowl or plate if you leave more clay in contact with the wheel head than you plan to leave on your final piece. The extra clay supports the piece while you're throwing so that it won't sag into a shape that you don't want. You don't have to be terribly concerned about the details of the foot while you're throwing unless you're not going to do any trimming later at all.

Deb R.

Hi Deb :-)

That's a good point about support! I don't trim totally to the foot I want, but I do try to trim off quite a bit. I will try your suggestion.

As for the rib - I tried it just now - and it dried the clay and then caught on it. Not that the piece was going to end up as anything wonderful, but still.

Marianne

Just quick answers, so waiting for computer. Grogged for handbuilding, some heavily grogged for large coil pots Paperclay for sculptural. Not grogged for throwing. A slighty course stoneware or earthenware if you want something with a bit more "tooth" or fine white clays, or porcelain. Sponges are very useful, but can be overused. Smoothing with a metal rib is best at the throwing stage to get a smooth finish. When you have turned your work sponging over with a slightly damp sponge, not wet can get rid of any sharpness especially around feet etc.

Just use the rib right at the end of throwing to smooth it over.

If you throw dry you use the rib to pull all of the slip/water off of the piece that you can because having a 'wet' spot will cause the clay to grab and give you uneven spots.... Even if you do not like to throw dry it is a good exercise for getting a feel for moving the clay. Basically you do your first pull wet (where you even out the walls after opening up), rib off all of the slip/water inside and out and then the rest of the pulls are done dry. It feels really weird but it is something worth trying and it is also a good exercise to help to throw dryer even if you do decide to go back to wet pulling.

Okay - I will try that and see how I go. When my teacher showed me, it seemed quite easy. But doesn't the quality of the clay matter a bit on how much your fingers will stick to it?

Marianne

To dry throw successfully, your clay cannot have any wet spots, *and* your fingers have to be dry. If you have a wet spot or if you have wet fingers, your hands will catch. Keep an old towel on your lap to dry your hands, and rib off the clay really well.

Deb R.

Thank you for adding the NO wet hands part. I had forgotten to do so.

Porcelain can be tough, very nice, kinda like trowing cream cheese. I use Laguna Clay works B-mix with no sand. It's a very strong clay, but is smooth. It's great fro throwing, and hand building. There is also what they call 50/50, which I believe is half sanded clay, half non-sanded. It's good to. Good luck.