Should I invest in a slab roller?!

[Cath Keher]

Hi there! 
I make porcelain brooches mainly using porcelain. I am currently rolling out my clay manually. I try to move it as little as possible, dry it really slowly but I am still getting curling in finished pieces. This is very disheartening as I do detailed sgraffito work on them so a lot of time is being wasted. Would using a slab roller help with this? It’s a bit of an investment so I would love to know if anyone has experience with them.

[oldlady]

it sounds as though you are spending a lot of time working on each piece.  a slab roller will help you get a maximum amount of flattened clay in a short time.  the problem is then holding the clay in workable condition once it is cut into shape waiting for further treatment.  if you want to cut a large slab into shapes to work on later, put them into something that will hold them.  using a plastic box with an inch or so of plaster in the bottom is an option.  wetting the plaster so the moisture level is constant is all you need to do.

once the pieces are finished, putting them between drywall sheets for drying will keep them flat.

so, no, i do not think you need a slab roller, just a different way of working.

[Bill Kielb]

When something flat dries unevenly from top to bottom  or even perimeter inward then it  is often prone to curling..  Obviously  bending  or deforming while handling stretches locally so that area may return  or reflect later.

A slab roller is great but still requires all the handling issues as that of a hand rolled piece. No doubt a slab roller is far easier but a hand rolled piece properly rolled and flipped and  rerolled can be as good or even better in compression than some slab rollers.

Finally firing on a flat surface is certainly critical as well.

Maybe tell us your process from rolling to drying, include any intermediate compression such as I use a credit card and compress in two directions and finally add  some pictures and folks here may have ideas.  Add your best thoughts on when these are being deformed.

My best thought without knowing  the how you do what you do is to use a drying process that is even from top to bottom

 

[Min]

One more thing to add that could help, after you roll out the slab take the board it's on and drop it from waist height onto the floor a couple times. Helps take any uneven clay memory from how it was rolled out of the clay slab. 

[Cath Keher]

Thank you all - such great advice here! You may have saved me a lot of money! I will document the process the next time. I have never turned over the clay during rolling for fear picking up the edges is what makes it curl. I then just leave the rolled out slabs on boards with canvas lightly covered with plastic and gradually uncover over a 3-4 days - day 2 I use cutters to make the shapes and leave them to dry still surrounded by the clay.

I tried drying between two drywall sheets once  but they dried so quickly they cracked so I didn’t do that again

I really appreciate all your effort to reply - I am self thought so any help is just so good.

If interested my Instagram is @perdozendesign and website perdozendesign.ie 

[oldlady]

cath,  i am also self taught but with a lot of very good books from the library.  and workshops when i could afford them.  and getting to know local potters by visiting studios and asking questions.  if you put your location in your avatar, we will not send you to a store that is located across the country or in another hemisphere.

the pieces you dried did not crack because they dried too quickly, they cracked from some other reason, probably handling them in transit.  you WANT the finished pieces to dry and the quicker, the better so you free up space.  slapping them down on the drywall keeps them flat if you can do that.  or follow min's suggestion above.  great idea.   i make most of my pieces flat and dry them as fast as possible.   slow drying is for those pieces that have attachments, like handles that need to balance the moisture content as they dry.

an important thing for you to know.  do not use canvas.   it holds silica dust that you can inhale though you cannot see it.   can cause serious lung problems.  especially do not pound on canvas.   use something else.  this has been discussed here forever.   yes, you can see potters on youtube using canvas.  do not do it.

why do you leave the surrounding clay after a shape is cut??  strange.

 

 

[neilestrick]

While a slab roller will not fix whatever technical issues you're having with the clay, it will save a ton of wear and tear on your arms and wrists. Slab rolling is exactly the kind of pressure that can cause tendonitis and  carpal tunnel problems in wrists. So if you have the space and money, and slab rolling is a big part of your clay working process, it would be a wise investment.

[Cath Keher]

1 hour ago, oldlady said:

cath,  i am also self taught but with a lot of very good books from the library.  and workshops when i could afford them.  and getting to know local potters by visiting studios and asking questions.  if you put your location in your avatar, we will not send you to a store that is located across the country or in another hemisphere.

the pieces you dried did not crack because they dried too quickly, they cracked from some other reason, probably handling them in transit.  you WANT the finished pieces to dry and the quicker, the better so you free up space.  slapping them down on the drywall keeps them flat if you can do that.  or follow min's suggestion above.  great idea.   i make most of my pieces flat and dry them as fast as possible.   slow drying is for those pieces that have attachments, like handles that need to balance the moisture content as they dry.

an important thing for you to know.  do not use canvas.   it holds silica dust that you can inhale though you cannot see it.   can cause serious lung problems.  especially do not pound on canvas.   use something else.  this has been discussed here forever.   yes, you can see potters on youtube using canvas.  do not do it.

why do you leave the surrounding clay after a shape is cut??  strange.

 

 

So in trying to use dry wall- the clay stuck to the paper of the drywall - so then I tried again with canvas in between (I did not know about canvas - what do you use instead?) 

Yes I leave on the surround so the edges of the pieces don’t dry faster than the middle. I’m very confused now because I have much better success with drying slowly than quickly.

In all the reading and YouTubing I do I can’t find anyone making what I do so there is so much trial and error!!

thanks for your advice

[Min]

Drying evenly is important, fast or slow. I would roll the clay on both sides and in all directions, sandwich it between two boards to flip it over, this way you aren't picking it up and stretching one side more than the other. 

[Smokey2]

9 minutes ago, Cath Keher said:

So in trying to use dry wall- the clay stuck to the paper of the drywall - so then I tried again with canvas in between (I did not know about canvas - what do you use instead?)

I place newspaper under and over the clay. If the clay needs to shrink the paper will slide against the drywall.

[Cath Keher]

8 minutes ago, Min said:

Drying evenly is important, fast or slow. I would roll the clay on both sides and in all directions, sandwich it between two boards to flip it over, this way you aren't picking it up and stretching one side more than the other. 

Super advice thank you- I will definitely start doing this!

[Cath Keher]

3 minutes ago, Smokey2 said:

I place newspaper under and over the clay. If the clay needs to shrink the paper will slide against the drywall.

Great I’ll do this - thank you!

[Sorcery]

What size are your final pieces?

I would shape a pug or hunk into a log the diameter of your final piece plus some waste edge for your drying trick, and cut em like this.

These are magnets, you just need to get them in your thickness. Then you can slice up a log quick, and leave them to peel off as needed.

You can do it with a standard slats set, but it's a lot of "slatmath".

If they don't need to be translucent, add some fine porcelain grog, I use Standard 130 and love it.

Sorce

[Cath Keher]

48 minutes ago, Smokey2 said:

I place newspaper under and over the clay. If the clay needs to shrink the paper will slide against the drywall.

 

32 minutes ago, Sorcery said:

What size are your final pieces?

I would shape a pug or hunk into a log the diameter of your final piece plus some waste edge for your drying trick, and cut em like this.

These are magnets, you just need to get them in your thickness. Then you can slice up a log quick, and leave them to peel off as needed.

You can do it with a standard slats set, but it's a lot of "slatmath".

If they don't need to be translucent, add some fine porcelain grog, I use Standard 130 and love it.

Sorce

What a super idea! Thanks so much for sharing 

[oldlady]

if your pieces stick to drywall, they are too wet.   how big are these things?

[Roberta12]

Cathy, I make a lot of small pieces for earrings and right now I am making hundreds of ornaments.  I roll out just as much clay as I can easily manage to get cut into shapes.  I take the shapes out of the clay that I cut from, put them on 9x9 drywall squares and stack them up.  I do not let the porcelain pieces sit very long because they dry so quickly, I only work on a few of those at a time.  That enables me to get holes put in them or kanthal wire bent and inserted.  But I can roll out slabs, put them on plastic covered wareboards, covering each sheet of clay with plastic top and bottom and stack those up.  They will be ready and waiting for me when i can get to them.  Stoneware is more forgiving and I can roll out each slab, cut the shapes, put them on the 9x9 squares, stacked and by the time I have 30 or so cut, I can go back and put holes or wires in the ones on the bottom, clean up edges, and work my way up.  Yep, that's what I was doing today.  Making ornaments.  I made 150.  

I bought a slab roller 6 years ago when I had shoulder surgery.  It is a game changer for certain.  I have a small one, that is considered portable, and it's terrific.  I think it's 18 inches wide.  It paid for itself in a few months.  Like @neilestrick it saves wear and tear on your body as well as speeding up the slab process.  

If what I wrote doesn't make sense, DM  me.  

Roberta  

[Roberta12]

Cathy, PS. just looked at your instagram.  Your jewelry is soooo  cute!!  

Roberta

[Cath Keher]

5 hours ago, Roberta12 said:

Cathy, PS. just looked at your instagram.  Your jewelry is soooo  cute!!  

Roberta

Oh Roberta- thank you so much for taking the time to describe your process - there is so much in there that I can try on my next run! Great to know too that a small slab roller is effective- it’s definitely very tempting as it is my least favourite part of the process. I love your work- great to find you!
 

[LeeU]

I've been making small thin pieces for a while now-currently into herb markers, pendants, flat ornaments. I don't wedge-I use cut & slam & then I use a table top slab roller and that helps with the body wear & tear as much as uniformity; I dry between drywall sheets (porcelain & stoneware). I had problems with cracking/curling-it was simply that the clay was too moist and my handling process needed fine-tuning. My slab roller is the 22"  from Bailey-I highly recommend them. It sits on the end of my glazing table, which is just a utility fold-up./ (small home studio). 

[Cath Keher]

On 12/7/2020 at 2:57 AM, LeeU said:

I've been making small thin pieces for a while now-currently into herb markers, pendants, flat ornaments. I don't wedge-I use cut & slam & then I use a table top slab roller and that helps with the body wear & tear as much as uniformity; I dry between drywall sheets (porcelain & stoneware). I had problems with cracking/curling-it was simply that the clay was too moist and my handling process needed fine-tuning. My slab roller is the 22"  from Bailey-I highly recommend them. It sits on the end of my glazing table, which is just a utility fold-up./ (small home studio). 

Thanks for your comment! And this is actually the slab roller I was looking at - so great to get a good review of it. Thanks for sharing your process - I’m inspired to tweak processes I abandoned too quickly. 

[LeeU]

Like most major suppliers who get mentioned here, Bailey has excellent customer service and will speak with you as much as needed, always pleasant, patient, and very knowledgeable. 

[Bam2015]

Cath, I vote yes for a table top slab roller. I have a North Star. I don't regret this investment. 

To move the rolled out clay, I simply place a board over the clay and flip the canvas over. 

Betty

[Chilly]

If you have the funds, it's a body saver.