Adding a foot to large vessels

[Kohaku]

I've been making some larger vessels lately (25 inch diameter in some cases). See image below.

I'm curious as to whether there are any home-studio scale approaches to adding a foot to these. I can clean the outer edge of the base on the wheel- but if I want to add a foot, I would need to A) flip one of these monsters, and B) use a bat with an adequate diameter. The biggest commercial bats seem to be 18 inches in diameter. In theory, I could make larger bats using plywood and a jigsaw- but the mechanics of trimming over a rotating disc on that scale make me a bit nervous.

Any suggestions? Do most people who make vessels on this scale just trim off the wheel head?



 

[Hulk]

Big bat, or huge chuck?

Nice pot!

Please stay well upwind o' your cobalt fumes, 'k?

[Kohaku]

No cobalt in that image! Just silicosis inducing clay dust (which I also stay upwind of)

[Hulk]

,)

"Huffing cobalt over a Raku kiln"

[oldlady]

gorgeous  pot!   be sure to let us know and photo the finished product, it will be spectacular.

what about applying 3 decorated feet like the potters who make huge planters?   there is a video on youtube from england showing what i mean.   will look for it.

[Kohaku]

2 hours ago, Hulk said:

,)

"Huffing cobalt over a Raku kiln"

Hah! Talk about my old indiscretions coming back to haunt me.

<Edit> Oh... it's my sig line. That's what happens when you don't log in for a year or so.

[Kohaku]

13 minutes ago, oldlady said:

gorgeous  pot!   be sure to let us know and photo the finished product, it will be spectacular.

what about applying 3 decorated feet like the potters who make huge planters?   there is a video on youtube from england showing what i mean.   will look for it.

Thanks- that would be awesome. I'll post a photo when the behemoth is fired.

[Mark C.]

I like homemade jumbo bats made from formica covered flakeboard-(sink cut outs-for free from cabnet shops)I cut them round on a band saw-or a jig saw.

Plywood that is sealed works just as well. 3/4 inch is best

I have a stack of them

[Kohaku]

5 minutes ago, Mark C. said:

I like homemade jumbo bats made from formica covered flakeboard-(sink cut outs-for free from cabnet shops)I cut them round on a band saw-or a jig saw.

Plywood that is sealed works just as well. 3/4 inch is best

I have a stack of them

Thanks Mark. What's the largest diameter bat you've used? (I guess '26 is my limit, being the inner diameter of my kiln).

[Mark C.]

24 inch is my largest bat. I have some 22 and and 20 inch-used  to use these when I was young and dumb. I have a few 28x14  inch kiln shelves when I did huge platters back in the day. 99.9 of my kiln shelves are 12x24 advancers now.Small stuff is my bread and butter these days-

nice pot

[Magnolia Mud Research]

3 hours ago, Kohaku said:

I've been making some larger vessels lately (25 inch diameter in some cases). 

I'm curious as to whether there are any home-studio scale approaches to adding a foot to these

some non-textbook approach's:

A technique from David Hendley for adding "feet" on pots was to make the feet separately and at the glaze firing, attach the feet on the pot using a stiff glaze between the pot bottom and the top of the feet.  For these large pots, throw foot rings separately and place them on the kiln shelf, put glaze on the bottom of the jar and on the top of the foot ring, set the jar on the foot ring, and fire away.  Chose a stiff glaze -- i.e. a glaze that DOES NOT run!  

I have done this on cone 10 ware using a shino glaze as the "glue" for the feet.   Works just fine.

You might be able to do the same idea at the leather hard or even bone dry stage.  
In some materials testing,  gerstley borate between two pieces of green ware in the bisque firing fused the pieces.  you might try that approach. 

LT
 

[neilestrick]

I'd make a bat from particle board or MDF and seal it with urethane. Either of those will likely be flatter than plywood. As much as I like to put a foot on everything I make, I'm not sure I'd mess with it on something that big.

[Kohaku]

1 hour ago, Magnolia Mud Research said:

some non-textbook approach's:

A technique from David Hendley for adding "feet" on pots was to make the feet separately and at the glaze firing, attach the feet on the pot using a stiff glaze between the pot bottom and the top of the feet.  For these large pots, throw foot rings separately and place them on the kiln shelf, put glaze on the bottom of the jar and on the top of the foot ring, set the jar on the foot ring, and fire away.  Chose a stiff glaze -- i.e. a glaze that DOES NOT run!  

I have done this on cone 10 ware using a shino glaze as the "glue" for the feet.   Works just fine.

You might be able to do the same idea at the leather hard or even bone dry stage.  
In some materials testing,  gerstley borate between two pieces of green ware in the bisque firing fused the pieces.  you might try that approach. 

LT
 

Intriguing... I'll have to try this (both the glaze and the gerstley approaches)

[Pres]

I would throw a pot with a base similar in size to the pot with a flared form, keeping it thick, with a nice rolled rim.  Trim it with as if trimming a foot ring, but keep the base thicker with about a 2"diameter hole in the center, and the edge of the foot ring over the wall of the pot so that when turned over the piece would act as a foot for your large piece, and then fired glaze together as others have said. Otherwise use coils of epoxy putty between the two pieces to glue them together. I have used this in the past, glazing the two pieces together, and it worked well. Hope you can visualize this.

 

 

best,

Pres

[CactusPots]

Beautiful pot.  I wish I had your decorating skills.  If I ever succeed throwing large, here's how I'm going to do it.  All my techniques for footing pots are too much trouble for the big stuff.  They're hard enough as it is.  If you have an extruder, make them in different sizes.

[oldlady]

sorry, kohaku, i cannot find the video i was thinking of.   there is a great one on Wichford  pottery showing how they make huge planters.   you might just use their method of rounding off the bottom instead of making a foot.  the pot you have shown really does not need one, it is a graceful line from top to bottom.

at a workshop, a nearby potter showed our group how to throw a huge pot upside down.  he left about 2 inches of clay in the bottom to use later as the top and he left the intended foot at the top very thick while he used a heat source to strengthen the bottom.   after lunch, he then threw the top which became the foot.   when finished, the pot was like a huge chalice with the rounded bottom flowing into a graceful foot.  the base was on a normal sized bat.   once that part was dried a little, he used the saved clay that had been originally on  the wheel and threw it into a top.  

the heat source was one of the big burners from his large gas kiln.    i have made one like his using a heat gun but it is nothing like the size he did.  my top rises to a small opening and it has a lid.

this is difficult to put into words, tomorrow i will take a photo after replacing the camera batteries.