A Jar with a Perfectly Fitting Lid

This jar is made on the wheel; thrown as one piece, a hollow form.

After the bottom and diameter are established, the walls are brought up and closed at the top.

This one has a top-knot, but you can make it rounded or add anything you wish after it becomes leather hard.

The walls are purposely thrown a little thicker than usual in order to accommodate the cut for the interlocking lid flange and the base lip. It's also good to make the jar a bit taller, since the lid cutting operation will take some height out of the middle.

This glaze is done with a splotch of green glaze on the bisqued piece, the application of wax resist over that, then the top and base are dipped in a contrasting glaze.

No matter how well matched the lid and base are, there is always the 'perfect seat' of fit. Making a decoration travel from lid to base helps to make sure the lid is returned to this optimum fit.

Below is a diagram I developed to illustrate the technique for cutting lids from closed forms. 

If you click on the image, you can enlarge it for easier reading. With some computers, you can click the curser on the image, hold and drag the image to the desktop, then import it into a document for reference.

If you cut the lid flange at the base of the indentation, it is possible to remove the completed lid and inner flange. Just a bit of smoothing up is needed.

The base, still attached and centered on the batt, can be trimmed on the inside to create a 'shelf' for the lid flange to rest upon.

Unfortunately, I don't have any examples to photograph of the jars I've made using this approach, I've sold them all except for this green one.

It is possible to reverse the cut--make it so that the lid slips down over the bottom flange--by cutting at the top of the indentation to release the lid, then inverting the lid into the base and after securing it, cutting the inner edge, leaving the outer surface undisturbed.

The outer edge of the base may need some cutting adjustment on the inner lip so that the lid slips easily over. This is an example of an early try at the reverse cut.

Once you get the hang of the cutting and a feel for the thicknesses, either way is fine, but I prefer the first method because in my experience, it gives a truer fit.

Experimental Lids

I am fascinated with lid design--thinking past the usual knob.  

This is a medium sized jar with an experimental handle and is just as easy to grasp as a knob, if not more convenient.

In this case, the idea might even be expanded to a lid/scoop design. But in order to do this, the base of the jar would have to be more straight sided to make room for a scoop to work. (Both the top and bottom would have to be designed to work together.)

So other forms should be considered. 

A bar works. 

Or reverse your thinking and consider a finger hole recessed into a built-up lid with a sealing solid base below the finger-space.  I've made these, although I don't have one to photograph at the moment. 

Or something that locks down with another element; a working two-part lid design.   

Another brain-teaser is figuring out how to make a screw-top lid-- Just a simple, run of the mill, screw-top jar like the ones you have around the house--from the cabinet or refrigerator. 

David Hendley (http://www.farmpots.com) wrote a thesis about making a tap and die for these lids. Go to the tab "Writings and Publications" to purchase a copy. He discusses tap and dies and includes pictures of an aluminum tap and die set once produced by Bluebird, but these are not currently available.* 

 Just thinking about it puts my brain in a twist.

*PS  If anyone has a Bluebird tap and die set for sale, please let me know.

Cookie Jar

So the idea here was to make a cookie jar with a domed lid and a knob that was separate from the lid.

The knob was to be formed and fired separately.

I made a 'cradle' for the shell so it would nest into the area where it joined the lid.

There is a hole in the top of the dome lid and a corresponding area in the shell where the two are connected with a small bolt.

The inside of the shell is solid with no indication a connection exists.

When both the lid and knob had been fired, I used good old Goop and closed the end of the bolt with a small nut.

The design is an homage to the nautical decorations on pieces I so admired at the Royal Worcester Factory Museum in the U.K.

And the jar is currently is at the Art Stop in Tacoma, WA.

Holes

I heard something yesterday that just reached right into my skull and swiveled my brain.

I was talking to my local clay supplier and at the same time fitting plugs into the bottoms of a salt and pepper set when she said, "The holes don't shrink, you know, between when you make the piece and when you finish firing it."

"Whaaaaaa?" Brain said.

"Whaaaaa?" Mouth said.

"Yes. The hole doesn't get smaller; the clay shrinks, but the hole stays the same."


"Uaaaaggggg, Whaaaa?" Brain said.

Jeanette said to Brain,
"Call up that mental image of the hole in the bottom of the salt shaker.
Run the footage of the hole in bisque firing.
See the clay shrinking.
See the hole stay the same.
Run glaze firing footage.
Ask yourself, How can the hole shrink with glaze all over it?
(Milllisecond compiling)
Huh...... She must be right."

By golly, she must be right. I can't visualize the clay gathering up in the firing and shrinking the hole. I can visualize the clay platelets solidifying and the spaces between them changing and getting compressed or with glaze flowing over them, but I can't see them binding together to draw a hole up smaller.

Message to Brain:
Keep track of holes in things and measure after each firing to see if this is true.
File under Puzzle Section in Drawer Re: Screw-on lids and other mysteries. Could have a bearing on figuring out how to make these.

Que music from "Brazil".

Note: If I ever got locked up in stir, I could easily fill my time thinking about stuff like this.

Perfectly Fitting Jar Lid

This jar is made on the wheel; thrown as one piece, a hollow form. After the bottom and diameter are established, then the walls are brought up and closed at the top. The walls are purposely thrown a little thicker than usual in order to accommodate the cut for the interlocking lid flange and the base lip. It's also good to make the jar a bit taller, since the lid cutting operation will take some out of the middle.

This particular jar has a 'sprout' topknot type handle. The glaze is done with a splotch of green glaze on the bisqued piece, the application of wax resist over that, then the top and base are dipped in a contrasting glaze. No matter how well matched the lid and base are, there is always the 'perfect seat' of fit. Making a decoration travel from lid to base helps to make sure the lid is returned to this optimum fit.

Below is a diagram I developed to illustrate the technique for cutting lids from closed forms. If you click on the image, you can enlarge it for easier reading. With some computers, you can click the curser on the image, hold and drag the image to the desktop, then import it into a document for reference.

If you cut the lid flange at the base of the indentation, it is possible to remove the completed lid and inner flange. Just a bit of smoothing up is needed.

The base, still attached and centered on the batt, can be trimmed on the inside to create a 'shelf' for the lid flange to rest upon.

Unfortunately, I don't have any examples to photograph of the jars I've made using this approach, I've sold them all!

It is possible to reverse the cut--make it so that the lid slips down over the bottom flange--by cutting at the top of the indentation to release the lid, then inverting the lid into the base and after securing it, cutting the inner edge, leaving the outer surface undisturbed. The outer edge of the base may need some cutting adjustment on the inner lip so that the lid slips easily over. This is an example of an early try at the reverse cut.

Once you get the hang of the cutting and a feel for the thicknesses, either way is fine, but I prefer the first method because in my experience, it gives a truer fit. It is also possible to trim the inside (or outside, if you wish) of the base to make the walls thinner.