search  current discussion  categories  techniques - misc 

slumping or humping?/an addition

updated tue 13 apr 99

 

Marcia Selsor on fri 9 apr 99

Dear Vince,
That sounds like a neat idea. When I make molded shapes out of foam, I shape
the foam with a sure-form and put a thin coat of plaster over it sanding that
smooth. (I really hate those staic clinging beads from foam getting into the
clay. Bill Daley taught us this in College. The plaster also helps the clay
take shape very quickly even though it is thin. I thought this might be a good
tidbit to add to the method you mentioned.
Marcia in Montana

Vince Pitelka wrote:
>
> ----------------------------Original message----------------------------
> >What about the other way around? The slump mold, where you would coax
> >the slab down into the mold and get to see the inside instead?
>
> Jan -
> Steve Robison and Kathy Guss taught me a wonderful slump-mold method which
> is now a standard part of my colored clay workshops. We make slump molds
> out of rigid foam insulation board. With the thin stuff, cut it with a mat
> knife. With the thick stuff, cut it with a sabre saw with an adjustable
> foot, so you can set the blade at the angle you want. Draw the shape you
> want on the top, leave enough level area on top for any level flange you
> want, and cut the outer shape of the mold and the inner shape of the hole.
> You do not really need for the angle of the inside cut to be exactly what
> you want to end up with in your slumped pieces. Simply drape you slab
> across the mold, and gently drop the mold against the table a few times
> until the slab sags to the desired curvature. And of course you can coax
> the slab into place with your fingers if you wish. If you wish, you can use
> a deep mold and slump the slab to an even curvature, and add a coil foot
> when the vessel is leather hard. Or, you can use a shallow mold so that the
> slab slumps down against the table or board beneath, creating a flat surface
> at the bottom.
>
> I have never had any problem with the slabs sticking to the foam board.
> They seem to release easily, even if I leave the piece on the mold until it
> is dry. Of course, I roll out my slabs between layers of 10 oz. canvas
> duck, and put them directly onto the slump molds with absolutely no moisture
> on the surface, and the canvas texture no doubt helps keep the slabs from
> sticking to the foam.
> Good luck -
> - Vince
>
> Vince Pitelka - vpitelka@DeKalb.net
> Home 615/597-5376, work 615/597-6801, fax 615/597-6803
> Appalachian Center for Crafts
> Tennessee Technological University
> 1560 Craft Center Drive, Smithville TN 37166

--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/spain99.html

Veena Raghavan on sun 11 apr 99

Vince and Marcia,
Very interested in the methods you described. Could you tell us a
little more about the insulation form board, such as how thick it is? and
does one get this in a hardware store such as Home Depot? Does one just ask
for foam insulation board?
Thanks in advance.
Veena
Veena Raghavan
75124.2520@compuserve.com

Marcia Selsor on mon 12 apr 99

This is styrofoam board and comes in many thicknesses. Some people line their
shipping crates with it. I don't know what home depot has, but hardwares
stores and/or lumber yards have it.
Marcia

Veena Raghavan wrote:
>
> ----------------------------Original message----------------------------
> Vince and Marcia,
> Very interested in the methods you described. Could you tell us a
> little more about the insulation form board, such as how thick it is? and
> does one get this in a hardware store such as Home Depot? Does one just ask
> for foam insulation board?
> Thanks in advance.
> Veena
> Veena Raghavan
> 75124.2520@compuserve.com

--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/spain99.html

Vince Pitelka on mon 12 apr 99

At 01:23 PM 4/11/99 -0400, you wrote:
>----------------------------Original message----------------------------
>Vince and Marcia,
> Very interested in the methods you described. Could you tell us a
>little more about the insulation form board, such as how thick it is? and
>does one get this in a hardware store such as Home Depot? Does one just ask
>for foam insulation board?

Veena -
Rigid foam insulation board comes in various thicknesses from 1/2" to 3".
Get whichever one appeals to you, but as I said before, the thinner ones can
be cut with a sharp mat knife, while the thicker ones will need a sabre saw
with a long blade. This product goes by various different names from
different manufacturers, but just go to Lowe's or Home Depot and ask for
foam insulation board.

And something I failed to mention before - after you cut the opening in the
center, where the slab is going to slump, smooth the inside upper edge with
sandpaper. Otherwise, when you settle the slab into place, that upper edge
will cut into the clay.
Good luck -
- Vince

Vince Pitelka - vpitelka@DeKalb.net
Home 615/597-5376, work 615/597-6801, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166