I made a bucket of porcelain slip today. I’ve started experimenting with adding it to both thrown and slab pieces to add another tool to my texture vocabulary. It’s a little hard to see porcelain slip on porcelain, but trust me, when these come out of the kiln, they’ll be great!
Slip is easy to make.
- Put some warm water in a bucket
- Add scraps of dried clay trimmings – the smaller the better. It’s important that the trimmings are completely dried out, otherwise it’s much more work.
- Mix until it’s the right consistency. I like to use a stick blender – just make sure you keep your kitchen blender separate from your clay blender!
- Keep adding dry scraps of clay, blending and testing until the consistency is what you want.
- Test using the squeeze bottle
- To keep the slip from settling, and a little muratic acid. Vinegar is a very weak form of muratic acid, but you need stronger stuff. You can find it in smaller hardware stores. It’s used for cleaning concrete.
Note: Use gloves when handling and keep a box of baking soda nearby to counteract it if you spill any. It’s not a strong acid, but it still needs to be handled with care. I’ve spilled it on my hands and it hurts, but putting baking soda on it counteracts it and it’s never been a problem for me.
A little bit goes a long way! I used about half a capful for about 1 gallon of slip and it was actually a little too much. It thickened the slip too much and it wouldn’t easily flow through the bottle. I had to add extra water to thin it down some. If this were a glaze I was trying to keep in suspension, that would be a problem, but for the decorative slip, it really doesn’t matter.
Here are a couple more test pieces I tried. I like the potential. The best thing about this is if you don’t like the pattern, you can carefully scrape the slip off with a soft rubber rib or wipe it off with your sponge if you do it right away. Sometimes that leaves and interesting pattern that you can work with.