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Marcia Selsor

How To Make Simple Terra Sigilatta In A Plastic Bottle

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This method is so easy that it can be done almost anywhere.

 

SIMPLE Terra Sigillatta recipe.

Fill a plastic liter bottle with 3/4 full of water. Add 250 grams of ball clay and 1-2 drops of darvon 7 or sodium silicate. Shake and let the mix set for an hour or so..until you see three separate areas of the mix. Clear, light and dark. Keep adding drops maybe up to 7 drops after several settlings until the water on the top level retains a little color after an hour of settling.

Next, punch another hole in the bottle at the bottom of the lighter color mix ..the top 2 layers. This is the terra sig. Let it squirt out of the hole and catch in a container.

Wait until your piece is bone dry and apply to the piece with a soft brush. Burnish with a soft foam sponge after each application. Do as many as you like until it is as

shiny as you like it.

 

Marcia

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Love this idea. When you say to keep adding drops, do you mean sodium silicate/Darvan? And then do you shake it and let it sit for another hour?

yes.

add a few more drops of sodium silicate or darvon 7 and shake. let is settle. Keep doing this until there is a little coloration rather than clear water on top.

 

Marcia

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post-1954-0-18510900-1374842226_thumb.jpgpost-1954-0-33199800-1374841917_thumb.jpgHere are some photos.

Paola Paranetta, demonstrated this at La Meridiana during our Soft Raku workshop.not really thickened. There is just more suspension. It is very watery. Brushes on very thin coats. Brush strokes don't show.

I apply it to bone dry pieces.They buff up beautifully with the soft sponge.

post-1954-0-81067100-1374842481_thumb.jpg

post-1954-0-33199800-1374841917_thumb.jpg

post-1954-0-18510900-1374842226_thumb.jpg

post-1954-0-81067100-1374842481_thumb.jpg

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I shake the mix before brushing. By being watery, it goes on very thin. Additional coats also go on thin. I have been doing about 4-5 coats. This is after separating the sludge from the bottom.

This album in my gallery has all terra sig pieces fired in various methods.

http://ceramicartsdaily.org/community/gallery/album/586-saggar-horse-hair-feathers/

Marcia

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This method is so easy that it can be done almost anywhere.

 

SIMPLE Terra Sigillatta recipe.

Fill a plastic liter bottle with 3/4 full of water. Add 250 grams of ball clay and 1-2 drops of darvon 7 or sodium silicate. 

Dear Marcia, does it mean you are using the dry ball clay in a form of powder? 

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Yes. you can color with a stain. Most ball clay will fire out white.Sorry I didn't see your question sooner. I have been working in the studio.Redart make an ok red terra sig. I have some Apache clay that makes a redder terra sig but it hasn't been mined on over a decade.I haven't tried this simple method with anything but ball clay.

 

Marcia

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A couple questions, since we're on the subject:

 

What is the purpose of Terra Sig?  What distinguishes it, from other coatings, like underglaze.  Is it mainly used for processes, like pit firing, where other surface decorations wouldn't be as effective.

 

Is it used with Horse Hair Raku?

 

I thought I had another question, but it elludes me......So I guess my next question is, What is my next question?

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Benzine, I use Terra Sig when I want a burnished look without a lot of effort.  Applying it to pots and buffing it with an automobile polish glove or plastic grocery sack or--as Marcia suggested--a soft sponge.  I use it for horsehair raku, and for ware that I apply underglaze decoration.  I even (gasp!) use the dreaded Giffin Grip so the buffing goes faster. 

 

My Terra Sig is made the old-fashioned way of mixing my own clay goop until smooth, adding a dash of sodium silicate then let set for 48 hours.  I then pour off the top two layers and throw out the gunk at the bottom.  Stir well, and do the same again. 

 

I first started using terra sig as a way to make the foot of my pots smooth so they wouldn't destroy my grand piano (or Jim's).  Now I pretty much finish all my wares with it, as I like the smooth finish.  I think all ceramic ware should have this applied to the foot and wish I'd known about using it before I actually started using it. 

 

In pit firing and raku, using terra sig allows you to polish and shine parts of a pot and it makes a great contrast with the unpolished areas.  You end up with the unglazed areas in both shiny and matte black (caused by the carbonizing of the clay in post-firing reduction).

 

There's probably other reasons for other people, these are my uses. 

 

What was your next question?

 

Shirley

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Terra sig provides a nice polished surface. It takes carbon like Maria Martinez's black on black pots. The Greeks used it for the Black and Orange pots.It can seal the surface. As Idaho says it is used in Horse hair raku, saggar firings, etc. Some artists use it for a sensual finish of the surface of their pieces.It is an ancient technique.

here is a Greek Amphora

http://www.arthistoryspot.com/wp-content/uploads/2010/02/Amphora.jpg

 

Marcia

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Terra sig provides a nice polished surface. It takes carbon like Maria Martinez's black on black pots. The Greeks used it for the Black and Orange pots.It can seal the surface. As Idaho says it is used in Horse hair raku, saggar firings, etc. Some artists use it for a sensual finish of the surface of their pieces.It is an ancient technique.

here is a Greek Amphora

http://www.arthistoryspot.com/wp-content/uploads/2010/02/Amphora.jpg

 

Marcia

 

That brings back memories! That amphora is on a table in my office -- okay not the original which is in the Vatican, but a very expensive reproduction from Greece. I bought it because the pic on the amphora of Ajax and Achilles playing a game was the logo for a company I owned, Boulder Games, that sold historical simulations (board war games).

 

Jim

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