Alyssa Ettinger on sun 24 dec 06
so here's a conundrum... i use commercial porcelain slip (why? let's not go
there), and i was reconstituting scraps and i added too much water. not
good. since i don't have powdered slip, i can't add that to lessen the water
content.
i have several new gallons of slip ready to use, pretty thick, they need
only a tsp. of darvan and they're ready to go. should i mix one of those in
to spread around/lessen the water content of the batch? leave the bucket
open overnight? dry it out and start over? pulverize some dried slip scraps
and add them to the mix?
i'm just learning the scientific basics of slip-casting so please be kind!
alyssa
www.alyssaettinger.com
John Rodgers on sun 24 dec 06
Alyssa,
Pulverize some scrap to add to the mix to get the water/clay back in
balance. Once done, mix the reconstituted clay with some of your fresh
slip from your gallon containers. Mix on a half and half basis.
Do you know how to measure and adjust the density of the slip? Ideally
most slips for slip casting should be between 1.75 and1.85. I find my
slip clays perform best at the lower end of the scale. 1.75 to 1.78 - in
that range. Also, are you checking your flow rate with a viscosimeter??
Extremely important! I adjust my slips to flow so that the test
completes in 30 seconds. I have some beautiful slip.
If you have questions, drop me a note directly - off the list.
Regards,
John Rodgers
Chelsea, AL
Alyssa Ettinger wrote:
> so here's a conundrum... i use commercial porcelain slip (why? let's not go
> there), and i was reconstituting scraps and i added too much water. not
> good. since i don't have powdered slip, i can't add that to lessen the water
> content.
>
> i have several new gallons of slip ready to use, pretty thick, they need
> only a tsp. of darvan and they're ready to go. should i mix one of those in
> to spread around/lessen the water content of the batch? leave the bucket
> open overnight? dry it out and start over? pulverize some dried slip scraps
> and add them to the mix?
>
> i'm just learning the scientific basics of slip-casting so please be kind!
>
>
> alyssa
> www.alyssaettinger.com
>
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>
Lee Love on mon 25 dec 06
Hi Alyssa,
Does the slip settle out at all? If there is water at the top,
you can siphon it off.
With my ash glaze, I keep a bucket of thick glaze handy and
put that in if I get the glaze too thick. Maybe you could keep a
bucket of thick slip on hand for the same purpose?
--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
"When we all do better. We ALL do better." -Paul Wellstone
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