Wednesday, November 7, 2012

Finishing the Goblets....

The goblet pieces needed a couple of days to dry slowly under plastic.

Here's a nice stem ready for trimming.  I have several small Dolan trim tools that make this easy.  The base of the stem is still massive and solid, and I like to detail the stem before hollowing out the base,

I've gone to some pains to keep the small cup at the top moist  since most of the problems I've had in the past have to do with two two segments not joining up properly.

Here's that same base with some trimmed details.  If your stem is not centered carefully, it's hard to get nice results.  You can see the little Dolan trim tools in the photograph.

Just as soon as I get it shaped, I moisten the interior surface of the upper cup with a wet finger, and stick a piece plastic over it.

Here's another nice stem ready to use.  I will probably do just a bit of carving on some of the elements of the stem.

Now, it's time to trim out the foot.

I attach the vase that I made with the goblet components to the wheelhead.  This is a carefully thrown sacrificial piece that will be used as a chuck to trim the bases of the stems.

I want it to be quite moist, so the stem will stick to it during the trimming process.  I adhere the chuck to the wheel securely with fat coils of clay.

 When you make your chuck, take care to make the top opening wide enough to accommodate  the top of your stem.
A chuck like this can be use to trim bottles, small ewers, and many other pieces that are fragile or difficult to trim.

When the stem is well centered in the chuck, you can begin to trim.  I use the same small tools to hollow out the foot.

You can see how crude the base of the foot is when trimming begins.

I like to trim the out portion of the foot very carefully, so the goblet will sit flat. It takes some concentration for me to hollow the foot.  I almost always feel that trimming takes much more attention than throwing, but that is probably different for each potter.

You can see that the trimming begun.  There's a lot of torque on the base as you trim, so moderate your wheel speed carefully.

Here's a finished stem ready to use.  There is nice form detail on the stem, and the the base is appropriately sectioned for drying.

Now, for the joining.

With the cup portion of the goblet attached to wheelhead, score its' base and also score  the interior of the cup at the top of your stem.
I like to add a blob of nice thick slip to fill any voids in the space that might be created.

Position the stem upside down on the base and turn the wheel slowly.  You will be able to see if the stem is correctly positioned.  If it is plumb and centered there will be no wobble at all if the wheel turns.

You will have a little time to adjust the position - the slip helps with that.

Here are my stems and cups, all put together.  I will dry them upside down for a couple of hours before turning them over; being careful not to let them get too dry for some surface decoration.

Here are some finished goblets and chalices.  The chalices were thrown in one piece.

Sunday, November 4, 2012

Still Makin' Pots - Goblets Today....

Thanks to all of you who have encouraged me to post process and work on my Insomnia Pottery blog.  It's been a long since my last post, but I continue to receive emails from potters who have found it useful.

Today I am working in the studio to fill a kiln for Holiday sales, and wrap up a few small special orders.  Although I don't make goblets as part of my production work for shows and galleries, I have some in my studio and visitors see them and want to purchase them.  At this time, only a few chalices are left - just the thing for toasting your Dungeons and Dragons compatriots!  

To me, a chalice is deeper and has a shorter stem in proportion to the overall height of the piece.  Buyers prefer more traditionally formed  goblets with tall steps and capacious bowls.  I think ceramic goblets sort of take away half the joy of wine drinking - seeing the beautiful color of the wine through a crystal vessel. Therefore, let's use them for mead or hard cider or best of all, a delicious hot toddy....

I like to make goblets in two parts and join them.  Both sections are thrown off the hump.  The clay I am using today is B-Mix, which has many fine properties.  However, it will be the last day for it in my studio for a while...  I am going back to Georgies' Cannon Beach 10.  

I'm starting off with about 5 pounds of clay - enough for about 6 bowls and fairly thick stems.  If you are not making small pieces - lids, knobs, small tea-bowls - off the hump, I really encourage you to learn to do so.  

The only complex part is separating the object from the hump in a tidy and level manner.  I struggled with this for years until Portland potter Ken Pincus kindly showed me how to do it the right way.  If I can find a friend to shoot a little video of me doing this tiny but essential trick, I will post it here in the next couple weeks.  

In the meantime, we'll stick to the goblet making....
Here's what we want to make.  It's crude!  But it is closely thrown and well centered.  The fun part - refining the stem and adding ornament will come during the trimming process.  With a toothy stoneware clay it is possible to do more preliminary forming of the stem, but the slickery B-Mix - pretty wet, also - wasn't willing.

It's important to keep downward pressure on the top of the stem as you bring it up so it isn't hollow.  If you have been throwing spots on the wheel, it's counter-intuitive.

There is also that big, thick base.  I'll trim that out later so them stem is light and balanced.
 Here's a shot of the top of them stem.  A small rice-bowl shape is thrown into the top of the stem.

I usually cut the top of the stem off level with my string tool so that this tiny cup - about 1-1/2" in diameter - is perfectly symmetrical and  dead level.  The separately thrown bowl will nestle into this cup.

Like a spout, there is movement during the firing that can "unwind" the form.  If all is not level, your goblet may come out of the firing with a tipsy appearance that it just not acceptable.

Drying the stem carefully under plastic is simply essential.  The thin little top must remain fresh and moist so it will join properly to the cup.

Here's a nice prospective bowl for one of the goblets.  I usually make 6 or 8 stems and the same number of bowls and match them for scale and form when I do the joining.

I will dry them separately, and trim the bottom of each on to match the stem-top cups, then use a serrated rib to scuff them up, and mate the trimmed stem to the cup right on the wheel head.

With the wheel in motion, it's easy to see if the stem and cup have been matched correctly, and repair any "wobbling" that is the sign of an out-of-plumb join.

I'll show all this later this week with photos from the join-up.

This taller piece is one of the most essential parts of the process - a chuck for trimming the base of the stems.

I'll detail the shaft of the stem right side up, with the heavy base stuck to the wheel head with coils of clay.

Then, I'll insert the stem into this chuck upside down so the base is supported.  The chuck was carefully thrown to be well centered, and was not cut off the bat.  It may live to become a vase, but might also just be recycled.

I find it hard to trim out the inside of the stems but they will crack if the wall section is not reduced carefully.  The crack would be up inside, typically an S-crack, and won't spoil the pot.  But why not do it right?

Here's a nice set of components for some goblets of various sizes.   I will probably trim and assemble them tomorrow night.