Magic Water for slip

[Marla Stroup]

Magic Water is described as a means of joining two pieces of greenware or attaching handles that have broken off as well as closing cracks. I'm into experimental construction methods and want to try making slip with Magic Water. I will experiment with this and report back but I was wondering if anyone has had experience with this idea, the slip made with the MW?

The sodium silicate, which I had to order through the pharmacy is kind of freaking me out since it is used to stop holes in radiators, etc. 

Marla

[Nadine Mercader]

I asked for sodium silicate at my local pharmacy and they had no idea what I was talking about!  Where did you get it and what did it cost?  Thanks for the help!

[Norm Stuart]

When purchasing ceramic supplies, like Sodium Silicate also called Water Glass, the first place to look is either your clay and glaze material suppliers or Amazon.com.

Amazon.com Sodium Silicate

http://www.axner.com/sodium-silicate-liquid.aspx

Non-toxic sodium silicate or potassium silicate (both known as water glass) can be made by mixing ceramic grade silica or quartz sand with lye aka Drano (sodium hydroxide or potassium hydroxide) which produces a thick pH neutral solution.

Mix the sodium silicate with ammonia or any acid, such as vinegar, and micro-fine silica-gel is precipitated out as the acid or ammonia binds to the sodium or potassium forming a salt dissolved in the water.  This is used as "brick hardener" for soft kiln bricks.

Water glass is useful for several reasons. When dealing with ceramics or cement, the silicate binds with calcium and magnesium.

This makes cement impervious to water by forming a hard layer of insoluble calcium silicate and magnesium silicate on the surface. 

Calcium and Magnesium ions make water "hard" which makes clay particles repel each other.  Sodium silicate is added to clay or detergents to remove these "hard water" ions to deflocculate clay or glaze or eliminate the static attraction which binds clay and dirt to clothes, letting the detergent (surfactant) to float the dirt away from the laundry.

Other uses rely on the way the properties of water glass change as it is dehydrated.  When heated to 190 degrees F in a radiator it forms a solid which doesn't melt until 1,450 degrees F indiscriminately plugging both leaks and the radiator.  Once taken above Cone 015 in a kiln water glass is used as a flux to bind refractory ingredients like vermiculite into bricks. These two properties, as water glass dehydrates and melt, make it a useful but brittle cement for metals or cardboard.

Because water glass absorbs a tremendous amount of heat as it dehydrates, it's also used to make building material fire resistant.  As the fire dehydrates the water glass, it cools the wood surface it's applied to, delaying the time it takes for a direct flame to char and burn the wood.

Nadine Mercader said:

I asked for sodium silicate at my local pharmacy and they had no idea what I was talking about!  Where did you get it and what did it cost?  Thanks for the help!

[Marla Stroup]

I got it at my local CVS. The pharmacist asked what I wanted it for and I told her it was for a ceramic project. She nodded in understanding. She said usually people want it to pour into an engine block (yipes!). It cost $27 for 30 fluid ounces. The company is called Humco. The label says: Sodium silicate solution, water glass.Traditional use, household and farm products. Then lists: carton sealing, gasket cement, sealing concrete floors and water proofing as typical uses.

I have switched to making my slip with 100% white vinegar and dry clay (crushed and ground up) for my slip, oh and am adding some toilet paper for the fibers just for good measure. I have been experimenting for several years with joining bone dry slabs using slip and gauze dipped in the slip as a construction method. In a recent firing, after many successful  pieces, I had one piece completely fall apart in my hands when I removed it from the kiln. I do not know for sure why this happened but I suspect that I forgot to add the 1/3 cup vinegar to the blender sized batch of slip I mixed up. If that's correct then I figured why not go with total vinegar and see if that is a better bonding set up? That was recommended by a potter as the recipe she uses for attaching handles. Thought I'd give it a try.

Nadine Mercader said:

I asked for sodium silicate at my local pharmacy and they had no idea what I was talking about!  Where did you get it and what did it cost?  Thanks for the help!

[Nadine Mercader]

Thank you Norm!  I now know how to find it.  I have wanted to use it on the outer surface to create the textured surface (there is a video here showing that.

I love this group and the great sharing spirit.

[Norm Stuart]

Before widespread electric lighting, chickens stopped laying eggs during the darker months of the year.

Eggs produced in the Summer and Fall were dipped in Water Glass (sodium silicate) which preserved the eggs so they could be used during the winter months. The silicates formed in the pores of the egg shells, like microscopic stalactites in a cave, sealed the egg off from pathogens and oxygen - something which wouldn't be compatible with a developing chick.

[Nadine Mercader]

Fortunately,  I am not old enough to remember those times!  I do appreciate the info though.