Kiln wash application with a brush

Kiln wash is applied thinly in a 1:5 powder to water mix to shelves and moulds.  The object is to get a complete coverage with a smooth surface. 

To ensure full coverage painting four coats is sufficient for excellent coverage.  The kiln was should be applied in four directions – horizontal, vertical, and each diagonal.  This ensures any gaps in one coat will be covered by the others. A broad brush that holds a lot of liquid provides good coverage.  A hake brush is ideal.  The brush should be held almost vertical with the ends of the bristles only touching the surface.

A traditional Japanese hake brush

There is no need to dry each coat before applying the next. It is not like painting your wall. All coats can be applied one directly after the other. No drying between coats is required.  In fact, earlier dried coats tend to make the application clumpy and streaky.

Some people advocate a fifth coat.  I don’t know what the fifth coat is for. What direction other than the four cardinal ones can there be?  It maybe it is insurance that the surface is coated evenly.  This can be checked visually.  The kiln washes used for glass are routinely coloured.  If the shelf shows unevenly through the kiln wash, a little more needs to be brushed onto the more thinly coated area.

It is possible to smooth the kiln washed surface once the kiln wash has a dusty surface – it does not have to be completely dry – you can put a piece of paper between the shelf or mould and your hand.  Gently rub the surface to get a really smooth finish to your kiln washed shelf.

 

More information:

https://glasstips.blogspot.com/2009/08/applying-kiln-wash.html

https://glasstips.blogspot.com/2009/08/smooth-kiln-wash-on-shelves.html