Recycled clay

[CactusPots]

Pretty sure I've posted on this issue.  My 2 main clays, both from Laguna, Soldate 60 and Amador, both release from my hydrocal bats quickly.  When combined into recycle, then won't release until almost bone dry.  I called Laguna, their explanation was that their pugmill has massive vacuum and my little PP 30 is a wimp by comparison.  OK, I thought, reasonable explanation.   I bought some too hard clay (also Laguna) from a friend, used Mark's procedure to soften the clay using the pugmill and guess what?  It releases just fine.

Does this contradict Laguna's explanation?  Do I need another reason the recycle doesn't release like the factory clays?  

[Hulk]

Good question.

My first batches of recycle were mix of several clays, seemed to behave as well as new clay. I'm bagging it a bit wetter than what comes new, however, which I like better.

Since, I'm not combining different clays.

I do keep everything though: pour off clear water and keep all the sludge from the throwing water bucket (give it time to settle - tomorrow's good), all scraps, bits, all sludge cleaned off hands, tools, bats, wheel, everything. All the bits - trimmings, unused handles, rejects (lots of them, haha), oops, the bit left on bats (not plaster) - I'm allowing to completely dry, then slake down to a thick soup when it's time. Perhaps different if a pugger we had. Any road, for sure the clay is thoroughly wetted, then dried back to throwing consistency.

Last three batches of reclaim, tried adding in some of Nerd's reclaim mix, which I believe is 80 ball clay, 10 feldspar, 10 silica; there's a detailed post here somewhere ...see this thread, where dhPotter reposted and Nerd's post, the last one

https://community.ceramicartsdaily.org/topic/19047-reclaimed-clay

Doesn't hurt.

Are you keeping all the "fines" and giving the reclaim plenty of time?

I'm curious about the vacuum. I'm wedging with hands, not seeing any bubbles at all; seems to me there's either bubbles or not bubbles, from there, pulling on it with vacuum would have zero effect, I'd like to think.

 

[Min]

I don't think it's just the de-airing of the pugged clay from a home studio pugger versus that of an industrial pugger from a clay company, I think it also has to do with the difference of compression and drag between the machinery. Bit of a back story, I was having issues with my pugged clay, it didn't feel the same as clay out of the bag. I contacted Jim Bailey and he suggested reducing the size of the nozzle at the end of the pugger. I took a couple pieces of 3/4" ply and marked out the bolt pattern at the end of the nozzle and drilled out a 2 1/2" hole and bolted the ply onto the end of the nozzle. Original diameter of pug was 3 3/4". The additional drag of the 1 1/2" of ply at the output end plus the reduction of pug diameter by 1 1/4" has improved the quality of the pugged clay, it throws as new out the bag clay now. Jim also said that they found ^6 B-Mix to be almost doughy when pugged, of the bodies they test with it was the only body that came out like this. I don't use ^6 B Mix but that would be a good description of how my clay was coming out before I made the alterations to the end of the pugger. I don't know if this type of test would be possible with a Peter Pugger.

 

 

 

[CactusPots]

Everything goes into the recycle, throwing water, hand slush, lots of trimmings.  I pug at a really soft consistency in order to avoid "mealy" clay.  I age at least a couple of months, sometimes much more.  I like to throw soft clay, so that's one big advantage to the pug mill for me.  One thing I've noticed since I got the slab roller is that the recycle clay doesn't roll out  a smooth edge.  If fines where the issue, it would seem like I could add ball clay or something to the mix.  I have tried additions without noticeable success.  I can live with all that, I'm just perplexed at why the recycle clay adheres to the bat so differently. 

If the pugmill was causing the issue, I would think pugging new clay would cause the same problem.

[Min]

It sounds like the properties of your recycled clay are contradictory. The rough edges of rolled out clay indicate a short body however taking longer to release from the plaster seems like there is an excess of ball clay (or other small particle fines) in the recycled clay than the original two bodies it's made from which wouldn't happen unless you add more than what was originally in the two bodies. What happens if you wire off the pots made from the recycled clay? I know this isn't necessary with hydrocal batts but might be a simple solution.

I brought up my issue simply to illustrate that not all bodies pug the same. 

[liambesaw]

I've gotta ask, but do you ever get any soluble salts in your reclaim?  Like for instance a flocculated or deflocculated decorating slip, sodium silicate from doing crackle surface, Epsom salts in your throwing water, water softener in your throwing water, magic water from joining pieces, etc.

Because it kind of sounds like you have some sort of flocculant changing the chemistry to me.

[CactusPots]

Thanks for the input.   I don't add anything at all to the recycle, except the 2 clays that I work with.  I don't use any of the additives Liam was suggesting.  Min's advice pretty much sums up my conclusions.  I like the recycle for large pots that I'm going to wire off anyway.  There must not be any ball clay in the Soldate 60.  The reason I think this is that paper slip made from that clay never goes funky.  Paper slip from Amador or the recycle will get black and stinky.  Got to be the organics in the ball clay, yeah?  Maybe the recycle doesn't have enough of the ball clay from the Amador and enough of whatever magic the Soldate has either.

[neilestrick]

Your recycle is the combination of two bodies, so I wouldn't expect it to behave like either of the individual bodes.