Slip casting problem based on weather

[Haidar]

In rainy and cold season i can't figure out what is going on with my casting slip. Well, i don’t know much about casting slip i just have known a process of making it and maintaining same density(175) (in 100cc) and viscosity (40 secs avg) all season. Like, its raining today (28-32 degree celcious) but my slip is stuck with mold. If any how i pick it its just broke bcz of not getting strength in itself. Now help me plz, what density and viscosity i need to follow now in these rainy days as well as upcoming winter season (like 18-24 degree celcious).

Sorry for my poor english writing.

Edited Thursday at 03:58 PM by Haidar
Apology for english writing mistake

[Jeff Longtin]

Welcome to the Forum Haidar.

Are you mixing the slip yourself? Can you post the recipe? 

I have found mold (green stuff) to be more recipe related and not so much weather related. Kaolin's from England grow mold quickly while Kaolin's from the US grow mold very slowly. Do you know where your Kaolin comes from?

The strength issue could be related to over deflocculation. (If your deflocculation is off than you may be adding too much water to make the slip thin.)

[Chilly]

On 10/10/2024 at 4:52 PM, Haidar said:

winter season (like 18-24 degree celcious

Oooh, I wish winter in the UK was this warm  . 

I have problems with slip taking a long time to set up in temperatures lower than 15C.  The worst weather is damp.  It can take 10 minues in dry 20C and 30 to 60 minutes in damp 10C.

I have not had problems with strength, only the amount of time it takes to become thick enough to pour out and dry enough to un-mould.

And your English is very good, I understood your question.  I hope my answer might be a little bit helpful.  Sorry if it doesn't answer your question.

 

[PeterH]

On 10/10/2024 at 4:52 PM, Haidar said:

In rainy and cold season i can't figure out what is going on with my casting slip.

Any chance it's a humidity issue and your molds aren't drying out fully between pourings?

Might be worth drying one out for longer between castings to see if it makes a difference.

PS An old thread discusses force-drying molds. This post seems to give the least-intrusive method.

From another of the posts -  put some supports under the mold so that the bottom dies out at a similar rate as the rest of the mold..

Edited Sunday at 02:35 PM by PeterH

[Mark C.]

I live in a rainy area and what helps is blowing air over the molds with a 2foot x two foot box fan to dry them and also to keep air moving over them