Plain Sodium Silicate as a surface treatment

[blackthorn]

Has anyone ever used just sodium silicate over bisque as a glaze?
I searched here for sodium silicate and found some info but only as an additive and not as a stand alone ingredient.
I’ll be testing in the next week but thought I’d ask what anyone’s experience might be.  
I’m looking for another surface treatment in similar to the attached, which was a thinly sprayed coat of Gerstley Borate.
I’ll post the results after testing if anyone is interested.

[Babs]

https://community.ceramicartsdaily.org/topic/5292-soda-ash-effect/

 

There are a number of threads in this forum re using conc soda ash washes which give a satiny finish.  A note speaks of damage to elements and kiln, and the sodium affecting anything under it as it fluxes. Nice finishes though

[PeterH]

What's forming the black image? Just wondering about any possible interaction with your glaze/wash.

PS No experience with either soda-ash or sodium silicate finishes.

Soda ash is best kept in a sealed airtight container to avoid reacting with atmospheric CO2. Conversely baking soda can be decomposed by heat into soda ash.

A hopefully minor point is that that different sources of "sodium silicate" are chemically different, because what is sold is a mixture of polymers of the general form  (Na₂O)_x·(SiO₂)_y, No idea if/when the difference is significant. In pottery it is usually sold as  70 or 140 degrees Twaddle: an archaic density scale whose use did actually help with the paperwork.

 

[blackthorn]

The Raven plate is black Mason Stain.  Not enough GB to cause any movement in it.
My guess is the sodium in the SS will be as fluxy as the boron in the BG but how glassy the silica will be is my main curiousity.  
From other posts I’ve seen Sodium Silicate used in conjuction with Soda Ash but I hadn’t intended to use Soda Ash.  
I don’t want to created a mini-soda firing in the school kiln.

One piece I’ll be testing is the plate attached below.  
Cobalt Carb and Victoria Green Mason stain (from the multi-color suggestion by Callie)
Pretty sure I’ve used too much cobalt but we’ll see.  AND  I'll see how much interaction there is with the SS

Thanks Babs and Peter,  for the helpful details you’ve sent.

[Jeff Longtin]

In years past it was suggested that Sodium Silicate could be used as a base for overglaze paints. (Mix Mason Stains with sod silicate, apply over a fired glaze, and refire to a low temp.)

I think Ceramics Monthly actually had a few articles about it.

Note: if you've never worked with overglaze paints they have a really toxic smell.  Using sod silicate was suggested as a less toxic alternative.

[blackthorn]

Thanks

On 11/19/2024 at 5:08 PM, Jeff Longtin said:

In years past it was suggested that Sodium Silicate could be used as a base for overglaze paints.

I've done the first test with a surface application of Sodium Silicate over bisque ware with various designs and the results are informative and quite unattractive.

I do some some possibilities with some changes in application and possibly mixing.  Posting the results below. 

[blackthorn]

[blackthorn]

[PeterH]

5 hours ago, blackthorn said:

I've done the first test with a surface application of Sodium Silicate over bisque ware

I'm confused about some aspects of the image, and a little concerned that the stain may not have stuck to the bisque after firing.

Looking at part of the image

A large area that should be  black hair is white-ish - why?
- Is a reflection off the "glaze" obscuring the underlying black image?
- Has the black image been disturbed, perhaps when you painted the "glaze" on?
 

[neilestrick]

One of the big issues with using Gerstley, soda as, etc as a wash is that it is not going to be at all durable. It's like using half of a glaze recipe. If you're just looking for a thin sheen, use a watered down glaze.