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raku problems - some solutions

updated tue 18 nov 97


Harvey Sadow on mon 17 nov 97

With the understanding that there are no easy answers, here is the easy
answer. Get a pyrometer. Using the same type of reduction materials
each time, fire a piece up to the cone that you usuallly fire to. Read
the temperature on the pyrometer. Then fire the next piece exactly the
same way, but 5 degrees cooler on the centigrade scale, and reduce the
same way. Then the next 5 degrees cooler, treated the same way,and
continue this progression till you have experienced a result that was
too hot, and too cold for your taste. When it's just right, Goldilocks,
try this......

Pay attention to the amount of time that you take to remove the piece
and put it into the reduction material. You can often affect the color
of the fired surface dramatically by the amount of time that you let the
piece cool in the air before you reduce it. This is more a matter of
seconds than minutes. Try pulling the piece and reducing it as quickly
as possible. Then pull the next piece and stare at it for 5 seconds
before you reduce it, then 10 seconds on the next. Pull the next one
and dance around in a circle for 15 seconds, then reduce, then 20
seconds on the next. Pull the next one and stare at it for 10 seconds,
dance around with it for 20 seconds and then reduce it. Look at the
differences between them. Accidents become techniques when you learn
how to repeat them. You can even affect the color of a copper bearing
slip by spraying the barrel that you reduce in with cold water, after
you begin reducing, to change the cooling speed in the reduction
environment. Barometric pressure affects raku results, too, as does
multiple firing sequencing and there are a lots of tricks for how to
reduce different ways for different results.