Can I Safely Decorate A Slabbuilt Greenware Flask With Slip?

[parryhotter]

Hi guys,

newbie question coming up.

 

Can a slabbuilt flask be decorated

With slip at the greenware to bone dry stage? (After spritzing with water spray).

 

Or, would the Fluid slip warp the slabs,by causing The exterior surfaces

To expand then shrink, whilst the inside surfaces are unaffected?

 

I'd be painting on two or three coats.

 

An informed answer could save a hours of work.

 

Advice much appreciated.

 

Steven.

[oldlady]

i have done this.  the moisture content of the item must be carefully judged.  if the pot is bone dry, put a damp cloth NOT A HEAVY WET TOWEL! around the entire thing and leave it inside plastic for a short time.  an hour or so could give it enough time to even out some moisture and allow you to add a THIN decoration. why do you plan to do two or three coats?  is your slip too thin for what you want to do?  what technique are you doing?

 

 do not try to wet the item more than it will take to apply a little slip.  if you attempt to dunk the entire thing in a barrel of slip and leave it there for a second or so, the new coating  will peel off in large sheets as it dries. now you know why you should plan your decoration and  get it done at the right time.

 

all of this takes some judgement which is developed with experience.  spritzing could work if you do it carefully and the clay is at the right stage of drying, the problem with spritzing is that it is so easy to do it unevenly and it can form wet drips that run down to the bottom of the item and soak into the clay there.

 

it is just possible that the flask will not survive no matter what you do.  try if for the experience while knowing the risk, that is the life of a potter. 

 

on another day and with a waster pot, learn how much clay will take before deforming.  dunk, not slowly dip or drip, a bone dry pot in a tub of water that will cover the entire thing.  immediately pull it out and watch what happens for a minute.  cut or break the pot and you will see how very little of the clay was wet by the dunking.

 

 just part of learning.

[parryhotter]

Hi, thanks for the info.

 

I was taught to do 3 coats of slip at a class I took; I guess 1 coat could do it.

 

In conclusion, I'm probably too invested in this piece to take any risks, and will go down the engobe route.

 

I've got a few other pieces, and will test your towel wrap technique on one.

 

Thanks,

 

Steven

[oldlady]

hope it works out.  my understanding of engobe is that it is slip.  with a few ingredients in it to ?????  if you have any dried up scraps, try the dunk it into water on a piece.  you will be surprised.

[Babs]

NOT a towel, old lady says, a cloth!!!!

Or poss a damp box.

[firenflux]

I've had success rehydration pieces by wetting a shop towel (the blue, stronger paper towels) and wrapping the piece in several plastic grocery bags for a few days.  

 

I use commercial engobes.  They can be painted on bisque ware like underglazes, so that should work regardless how wet the piece.

[oldlady]

thanks, babs.  this is one of those questions that seem simple to answer but are anything but.  maybe OP has made a 3 inch high ten pound flask which will never get damp again unless tossed into Niagra Falls.  maybe it is 10 inches high and translucent because it is so thin.  maybe his slip is like water or maybe it is like yogurt.  there is no answer, just trying to suggest a path.

 

i am still working on a very large sphere that was thrown during NCECA in tampa years ago.  it is still greenware and definitely bone dry.  i put a thick slip running cheetah on it originally.  added a hare running from the cheetah.  these were in relief and about little finger thick at the cheetah's shoulder. sort of a heavyweight Wedgewood. i added the hare, put a second cheetah and hare on the opposite side.  after several years i decided i did not want those animals so i scraped them off.  still intend to add something, just do not know what.  the dry pot is larger than a basketball and deserves some thought.  the potter who made it as a demo for Duncan was very generous to give it to me.  some day it may be a finished pot on my shelves.