Stoneware and porcelain slip

[Nicky S]

Hi ......I remember  reading somewhere that one can use a clay body  and then use “  porcelain slip “ over it . Is this feasible ? I use a stoneware that fires to  bisque 980 and glaze goes to 1020 degs . I fire my Audrey Blackman porcelain to 950 bisque and glaze goes to 1240 degs . My question is could I use “ porcelain slip “ on my stoneware ? And is there something extra I should be adding too the porcelaine  slip ?

Thank you Nicky 

 

[liambesaw]

Yep, you can dip or brush porcelain slip on stoneware.  Doesn't matter if it's a higher firing temp as long as the stoneware under it is vitrified.  A nice way to add a white coat.

[Nicky S]

On 8/25/2020 at 7:38 PM, liambesaw said:

Yep, you can dip or brush porcelain slip on stoneware.  Doesn't matter if it's a higher firing temp as long as the stoneware under it is vitrified.  A nice way to add a white coat.

@liambesaw Would just like to make  sure that I understood well .Porcelain slip can be  used on bisque fired stoneware . But not on greenware or leatherhard  stoneware clay 
Thank you Nicky 

[Chilly]

41 minutes ago, Nicky S said:

Would just like to make  sure that I understood well .Porcelain slip can be  used on bisque fired stoneware

No.

[Min]

4 hours ago, Nicky S said:

Porcelain slip can be  used on bisque fired stoneware . But not on greenware or leatherhard  stoneware clay 

Like Chilly said, no. You want to get the slip on the pots as soon as you can. Slip is going to shrink as it dries, if you put it on bisque it will crack and shell off. It needs to shrink with the pot so the sooner you get it on the better chance it has of staying bound on. For slip to go on either dry greenware or bisque you need to reformulate a slip recipe to remove some of the plastic ingredients (un-calcined clay) and replace it with non-plastic ingredients (calcined clay) so using a ready made porcelain as a slip isn't a good choice for dry greenware or bisque.

[Nicky S]

@Min Thank you Min .......... Appreciate your input and help .Will keep on trying .

[liambesaw]

The fish sauce slip recipe works good on bisque.  It has pyrophyllite in it, which allows it some play in shrinkage.

[Nicky S]

@liambesaw Think I have to give that a miss .... Way to advanced for me .Tho did look it up

Thank you . Nicky

[Mark C.]

I have slipped bisque ware but it was for the salt kiln and salt fluxed it very well to the pot.Salt will melt just about anything well.