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Had slip in pouring table to long and slip hardened.  It is low fire slip. We added water and add casting slip thinner. The slip seems thin enough but parts of greenware are collapsing while drying in mold. It was not emptied to quickly. It has desired thickness, but a portion of the greenwear collapses. It stays soft. It also seems to thicken up and not drain well. Any help is appreciated.

Paul

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22 minutes ago, momspindy said:

We added water and add casting slip thinner

What is the specific gravity now compared to when the slip is freshly made? Water evaporates, deflocculants don't so my guess would be it's over deflocculated. I've never mixed an entire batch from scrap which in effect your tank of dried slip is, don't know if this is part of the problem too? @Mark C. has done a lot of slipcasting in the past, he might know the answer.

Edited by Min
added a thought
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(We added water and add casting slip thinner)

I assume casting slip thinner is Darvon 7?

Min said (Water evaporates, deflocculants don't so my guess would be it's over deflocculated) 

That is right so all you needed was water so what you need now is more dry slip

Really you need a slip hydrometer(they are short and fat)  and a ford cup to measure the flow rate-without these tools and the specific gravity  # of fresh slip made right you are operating in the dark

Its been a long time since I was doing slip but those tools make all the difference .Like driving nails without a hammer

Edited by Mark C.
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7 minutes ago, momspindy said:

The specific gravity is 1. I add water to get it to 1.75.

Just checking here, if the specific gravity is one then that would be pure water with nothing in it.  Adding water to a mixture of water and slip usually decreases the SPG because the sample is being diluted. Just checking to make sure you have the measurement thing correct before you start to make adjustments.

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42 minutes ago, momspindy said:

The specific gravity is 1. I add water to get it to 1.75. will see what that does first. How to I counteract the darvon 7 if we added to much? Thanks

Add more dry slip to counteract to much Darvon 7. Do not add any more water. 

Get the ford flow  cup and learn how to use that for flow rates. Get the slip hydrometer and use that as well. You need them both 

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