Which side of plaster bat do you use for drying clay?

[SueDirani]

Hi folks,

I recently made a plaster bat for drying out my reclaim clay.  I used a large plastic tote container as the form for my plaster bat and it turned out beautifully.   There is a rougher side (the top of the poured plaster in the form) and a really smooth almost shiny side (the underside part that was against the plastic tote).  I'm confused about which side of the bat I should be using to put my wet clay on: the side that is rougher? Or the side that is super smooth?

Thanks in advance for any advice!

Sue

[Hulk]

Good question!

I've four slabs (made with a rectangular cake pan); light clays on one side, all others - red, brown, buff - on the other side.
Both sides seem to dry the clay well.

I'm setting the slabs on pieces of 1"x1" so air can circulate underneath, for once the plaster has absorbed enough water to be near saturation, evaporation from the surfaces of the plaster is (err, could be) more important in speeding things along.
Indeed, the 1"x1" edges against the plaster get rather wet!

Between reclaims, I'm setting the (wiped clean) slabs on their shelf with the 1"x1"s underneath and between, so they can thoroughly dry.
I'm seeing the plaster (my slabs are near 2" thick) holds enough moisture to start mold underneath and between...
It was taking several days for the plaster to thoroughly dry (we've since moved to a warmer and dryer climate!).

[Jeff Longtin]

Hello Sue. Either side will dry the clay equally well. The smooth side is simply easier to clean so I would use that side.

The next time you pour you might take a moment to watch the plaster set. At the 10 - 15 minute point the plaster will lose its water surface and start hardening. If you catch it in time you can use a straight edge scraper and lightly scrap the surface of the plaster. If you do this several times you will slowly develop a smooth surface. 

Its an acquired skill but one I use alot so that my textured plaster forms can easy sit on level surfaces. (Which reduces that chance they might warp as they dry.) 

[SueDirani]

Thanks, Tom (or Hulk?),

Great to know that I can use either side of the bat.  When I used the rough side, I noticed a couple of spots where minute amounts of plaster came up with the clay when I turned it over so I think I'll go with the smooth side next time.  And thanks for those other tips on drying the bat.

Sue

[SueDirani]

Thanks for the advice, Jeff!

[Chilly]

On 6/7/2023 at 6:05 PM, SueDirani said:

When I used the rough side

You can scrape the rough side to make it smoother.  You might need to use a rasp or fine cheese grater.  Or even coarse sandpaper.  Wear a mask and clean up properly afterwards.  I do such things on a board across the dustbin in the garden, dust goes straight in the bin.

Give it a good wipe down with an old, damp sponge after and allow to dry.

I,  like, @Hulk use one side for light clay, the other for terracotta.

[Babs]

3 hours ago, Chilly said:

You can scrape the rough side to make it smoother.  You might need to use a rasp or fine cheese grater.  Or even coarse sandpaper.  Wear a mask and clean up properly afterwards.  I do such things on a board across the dustbin in the garden, dust goes straight in the bin.

Give it a good wipe down with an old, damp sponge after and allow to dry.

I,  like, @Hulk use one side for light clay, the other for terracotta.

Do you use anything to help release the plaster from tin?

[Hulk]

I've used a layer of Murphy's soap on the cake, pie, and loaf pans to help the plaster release.

[SueDirani]

Thanks for all the great advice!

[Callie Beller Diesel]

Another thing you can do is cover the slab with a layer of fabric: an old sheet or pillowcase, size depending. 

[Pres]

Speaking of old pillow cases, try hanging one in a frame, and add your slop clay to it. Let the water drain, then when stiffer. inside out the pillowcase to release the clay and wedge.

 

 

best,

Pres