Making an oval pot - a potter tale retold

[mudlarkpottery]

Hi Paul, I have a couple of questions.
1. Plastic bats?
2. Is the top edge of the wall of the pot jagged, I can't see a close-up. If it is, why?
3. How thick is the wall compared to the base and the feet as well?
Penny.

[pjkatich]

Hi Paul, I have a couple of questions.
1. Plastic bats?
2. Is the top edge of the wall of the pot jagged, I can't see a close-up. If it is, why?
3. How thick is the wall compared to the base and the feet as well?
Penny.

Penny,

Yes, plastic bats.

No, the top edge of the rim ring is not jagged.

Normally, I will roll my slabs to around 1/4" (6 mm). The rim ring will vary, wider at the bottom (3 cm) and narrower at the top (6-7 mm). The foot ring will vary from pot to pot, normally around 1 to 2 cm in thickness.

I hope this helps,

Cheers,
Paul

[pjkatich]

After the pots have rested for a few days it's time to check on them.

I will take the pots off the shelf and remove the plastic along with the now damp newspaper.

Now that that clay has had time to rest and firm up, I will put the thrown pieces back on the wheel and have another go at them. The following photo shows one of the rim rings back on the wheel.

IMG_0020a.jpg

During this part of the process, I will fix any dings in the rim and adjust the profile of the rim ring. In addition, I will check the dimensions of the rim ring before cutting it from the bat.

Then, I will start the wheel and using a knife, I will cut the rim from the bat as shown in the following photo.

IMG_0021a.jpg

Next, I will process the foot ring in the same manner as shown below:

IMG_0022a.jpg

These procedures are repeated for the remaining two sets of rim and foot rings. The following two photos shows the profiles of the second and third pots:

IMG_0026a.jpg

IMG_0033a.jpg

At this point, the parts are still to soft to handle on their own. So, it's back in the bags along with some fresh, dry newspaper for a few more days as shown in the next photo.

IMG_0035a.jpg

Again, the goal here is to reduce and even out the moisture content between the individual pot pieces in a slow and controlled manner.

Any questions?

Time to take a short break.

Stay tuned - more to come.

Cheers,
Paul

[kitoi]

Missed this during the initial viewing...A plastic or wood knife?

I used the string clay cutter, it came of the bat but made a mess of things.

[mudlarkpottery]

Thanks, Paul, just curious. After going through several CM mags, I recognized several ads for those bats. I usually don't bother looking at them (except the Soldner ones and they haven't advertised for ages).
Penny.

[pjkatich]

Missed this during the initial viewing...A plastic or wood knife?

I used the string clay cutter, it came of the bat but made a mess of things.

ketoi,

I use a metal knife. With the wheel turning at around half speed, I will make my first cut from the outside about half way through. Then, I will finish the cut from the inside of the ring.

Yes, I have experienced the same problems using a string or wire cutter.

Regards,
Paul

[pjkatich]

Thanks, Paul, just curious. After going through several CM mags, I recognized several ads for those bats. I usually don't bother looking at them (except the Soldner ones and they haven't advertised for ages).
Penny.

Your welcome Penny.

One of the reasons that I use the plastic bats is to help control the moisture content of the pieces. Plastic bats will not wick moisture away from the clay like wood or plaster bats will.

This is a point I will emphasize, an even moisture content between the individual pieces is extremely important when it comes time to join them together.

Cheers,
Paul

[pjkatich]

During the week that has gone by, I have checked on the three pots several times.

Each time removing the now wet newspaper and replacing it with fresh dry newspaper. I would check the firmness of the clay each time to determine if the rings had dried to the right consistency.

It has taken seven days and three newspaper changes to get to this point. The amount of time may vary depending on your location. Keep in mind, we are trying to reduce the moisture content of the clay pieces as evenly as possible and maintain a uniform moisture content between the individual pieces of clay.

When I refer to the right consistency, I want the clay to be not quite leather hard. There is no technical term for this, it's more of a touchy-feely thing. If it is to dry the ring will split when it is pulled into an oval shape. If it is to wet, it will collapse when you try to pick up the ring.

If I can pick up the rim ring without it bending under its own weight then its time to move on to the next stage.

At this point, I place the ring on an even flat surface and gently pull the ring into an oval shape. I will use a tape measure or ruler during this phase to get the ring of clay to the proper dimensions. Keeping in mind that the final pot will be approx. 12% smaller when it is complete.

After I have pulled the oval, I place it on top of the slab as shown in the following photo.

IMG_0001a.jpg

I will then cut the foot ring into four equal pieces and place them inside the oval on top of the slab as shown in the next photo.

IMG_0003a.jpg

The next two photos show the other two pots at this stage of production.

IMG_0004a.jpg

IMG_0005a.jpg

I will then bag them up again with some fresh newspaper and put them back on the shelf to rest and firm up a bit more.

Any questions?

Stay tuned for the next installment

Regards,
Paul

[pjkatich]

Now, where did I leave off.

After a few days it's time to move on to the hard part - Attaching the rim ring to the slab.

First, I will take the pots off the shelf and remove the plastic and newspaper.

Then, I will put the rim ring on a stable, flat working surface as shown in the following photo.

IMG_0001a.jpg

Now, I will take a ruler and check the measurements one more time as shown in the following two photos.

IMG_0001b.jpg

IMG_0002a.jpg

This will pretty much be your last chance to tweak the dimensions of the oval rim ring.

Next, I will put the slab on a stable, flat working surface as shown in this photo.

IMG_0007a.jpg

Then, I will place the rim ring on the slab and get out your needle tool as shown in this photo.

IMG_0008a.jpg

Any questions?

Stay tuned - more to come.

Cheers,
Paul

[Bretts]

Hey Paul I am sad to say my first completed pot warped and spat two bits of clay at me from drying too quick. Lesson learnt and I have another 5 at various stages of development so I will survive.
Just disapionted I don't have it to show off any more I was very happy at the result for an amature

[pjkatich]

Hey Paul I am sad to say my first completed pot warped and spat two bits of clay at me from drying too quick. Lesson learnt and I have another 5 at various stages of development so I will survive.
Just disapionted I don't have it to show off any more I was very happy at the result for an amature

Brett,

Failure and disappointment is part of the learning process.

As long as we learn from our mistakes, our pots will only get better.

Cheers,
Paul

[pjkatich]

Now, I will take the needle tool and score a line into the top of the slab outlining the inside and the outside of the rim ring as shown in the following photo:

IMG_0009a.jpg

Next, I will flip the rim ring over, exposing the bottom of the ring as shown in the next photo. I normally use two ware boards to accomplish this task.

IMG_0010a.jpg

Then, using a scoring tool, I will score the bottom of the rim ring as shown in the next photo.

IMG_0011a.jpg

The following photo shows a close-up of the scored rim ring:

IMG_0014a.jpg

Next, I will score the slab in the area between the two lines I made earlier as shown in the next photo.

IMG_0016a.jpg

Also shown are a container of slip and the tools required to complete attaching the rim ring to the slab.

The slip is made from scrapes of the clay body used to make the pot pieces. I allow them to dry out, then I rehydrate the clay using white, distilled vinegar. This was a tip I got from my good mate Pat Kennedy and has proved to be a great help to me.

Any questions?

I'll be back after a short break.

Cheers,
Paul

[Bretts]

I was talking to the ladies at the pottery group about using vinigar in the slip. A very talented potter that is fairly new to the group suggested that adding paper to the slip does a better job.
This has lead me to looking into the very intresting subject of paperclay.
Even though the pot that dried out too quick was VERY warped and it had spat a couple of bits of clay off, all the joins showed no sign of any stress. I am thinking this shows that the joins were sound.

[pjkatich]

I was talking to the ladies at the pottery group about using vinigar in the slip. A very talented potter that is fairly new to the group suggested that adding paper to the slip does a better job.
This has lead me to looking into the very intresting subject of paperclay.
Even though the pot that dried out too quick was VERY warped and it had spat a couple of bits of clay off, all the joins showed no sign of any stress. I am thinking this shows that the joins were sound.

Soltan,

Do you mean adding paper to the vinegar based slip or adding paper to a water based slip?

I would be interested in hearing more about this.

Thanks for your input.

Cheers,
Paul

[pjkatich]

The next step is to apply a layer of slip to the slab as shown in the next photo:

IMG_0017a.jpg

Then, the rim ring is flipped over and placed on top of the slab as shown in the next photo:

IMG_0018a.jpg

Now, using a slight side-to-side movement, the rim is pushed done onto the slab. This will force the excess slip out from between the slab and the rim ring as illustrated in the following photo:

IMG_0019a.jpg

Once this part of the procedure is completed the bond is allowed to set up for a short period (approx. 1 hour) before the next phase begins. As shown in the next photo, the inside seam is then worked with a soft rubber rib.

IMG_0020a.jpg

The idea here is to blend the inside seam between the rim ring and the slab together, thereby, forming a good mechanical bond.

When this task is complete, I will apply a layer of slip over the seam to fill in any low or uneven areas. The next two photos shows what this looks like.

IMG_0021a.jpg

IMG_0022a.jpg

That's all for now.

Stay tuned for the next installment.

Have a great day.

Paul