Stains and underglaze with slip

[Nicky S 20]

HELP ..... ... Trying to get back to ceramics .I’ve just finished mixing a small quantity batch of stains  and underglazes with slip ( same clay bodies nothing else  ) I’ve used 60 % slip to the ratio of about 10% stain to both stain and underglazes  But have found that the underglaze slips are much thinner than the stain slips .Consistencies are different .Most stains  seems to be thicker than underglazes  Aside from black and purple which are def thinner . How to rectify ......????  Do I add more slip or stain to thicken  ??? Or is it more complicated than I imagine . ? Bare in mind I am not adding anything else ie frits etc 

Thank you Nicky 

Edited October 10, 2020 by Nicky S

[Min 3,722]

Just to clarify, you are mixing stains with slip and underglaze with slip at 6 parts slip to 1 part stain or underglaze?

Are you measuring by weight or volume, dry powdered slip or liquid? I'm assuming the underglaze is premixed and liquid? Slip is your own recipe or the same body as the pots are made from?

[Nicky S 20]

8 minutes ago, Min said:

Just to clarify, you are mixing stains with slip and underglaze with slip at 6 parts slip to 1 part stain or underglaze?

Are you measuring by weight or volume, dry powdered slip or liquid? I'm assuming the underglaze is premixed and liquid? Slip is your own recipe or the same body as the pots are made from?

@MinHi Min ...... Yes mixed stain powder  and underglaze powder with 60% slip (and 10%     stain or underglaze ) Slip is same body as the pots are made from.Αll premixed from same body

[oldlady 2,949]

nicky, in 2016 i did a series of tests of my slip with stains.    i used a white body and made the slip from dry scraps of slabs of that body.   you might want to look at my album showing the results.

some of the colors come out true to expectations and others simply do not.   the series of 11 photos is backwards, start with the last photo in the group and arrow back to the first.  this is just to let you know that some of the chemicals in the stains work with my clay and others simply do not.  it is not important to me to have a specific color that is always repeatable so i just use the ones that work and drop the rest.  if you are looking for an exact match from batch to batch, keep detailed records and  test, test, test.  which is what i did.

 

[Nicky S 20]

1 hour ago, oldlady said:

nicky, in 2016 i did a series of tests of my slip with stains.    i used a white body and made the slip from dry scraps of slabs of that body.   you might want to look at my album showing the results.

some of the colors come out true to expectations and others simply do not.   the series of 11 photos is backwards, start with the last photo in the group and arrow back to the first.  this is just to let you know that some of the chemicals in the stains work with my clay and others simply do not.  it is not important to me to have a specific color that is always repeatable so i just use the ones that work and drop the rest.  if you are looking for an exact match from batch to batch, keep detailed records and  test, test, test.  which is what i did.

 

@oldlady.... Thank you for your input .... not quiet sure where to see your test samples (?) 

[oldlady 2,949]

oh, sorry.   click on my avatar.  look for profile and find albums under that.  the last one on the first page is the slip tests.

[Min 3,722]

@Nicky S, okay so if it's just the consistency of the slip that is too thin but the fired colour is okay then you can thicken it up with some epsom salts solution or add some more dry clay and colourant. Like @oldlady said run some tests to see how much colourant you need, it could well be different for each colour. Blues and greens probably will need less colourant than say yellows, pinks and purples. Weighing out the dry clay and the colourant is going to give you the most reliable way to make subsequent batches of the same shade rather than eyeballing the slip consistency. This way you can adjust for the runnier ones.

[Nicky S 20]

@Minim sure I have replied .... but don’t seem to see .... Thank you for your invput ...... I have not fired the test tiles as of yet .... As I wanted to resolve the issues that I have:Ie underglazes very thin and stain rather thick But thank you Think I’ll just stick to different clays and forget about colors ( learning issue a bit of a problem :) 

 

[Nicky S 20]

2 hours ago, oldlady said:

oh, sorry.   click on my avatar.  look for profile and find albums under that.  the last one on the first page is the slip tests.

@oldladywill do ..... thank you