reconstituting bone dry clay the RIGHT way

[s6x]

to reconstitute clay I usually just leave the clay in a plastic bag and add water until it softens enough to wedge.  A friend recently informed me that I'm doing it ALL WRONG.  the ONLY correct way is to

1. make sure the clay is bone dry.  

2.  crumble it into small pieces and soak in a bucket of water for days.  

3. ONLY WHEN COMPLETELY DISSOLVED INTO A SLIP IS IT READY TO DRY.  

IS THIS TRUE?  Why do I have to dissolve it completely into a slip, if it's ready to wedge way earlier?  Is there some chemical reason I'm not aware of?  I found some videos on YouTube that claims this to be the correct way to do it as well...  

[Min]

If what you are doing works and is easy for you then there is no  reason to change. 

Some claybodies don't rehydrate well if they are semi dried out so for those it's easier to dry the clay until it's bone dry then slake it in water. Bone dry clay will slake down much faster than semidry clay. A slurry mixed claybody thoroughly wets all the particles so clay made from slurry mixed is considered nicer to work with but if what you are doing makes the clay just as good  then no reason to do anything different.

Welcome to the forum!

[dazzlepottery]

In my experience it depends on what you're trying to reclaim. It's tricky to reclaim a whole bag of clay that has dried too much to use. There is a whole process of adding a little water to the bag, poking holes in the block of clay, then submerging the sealed bag in a bucket of water. Mine always comes out too wet on the edges and still firm in the center and is tricky to homogenize. 

However with trimming scraps and failed pieces, I just add them to a bucket in any form (dry, leather hard, intact, crumbled) and add CLEAN water (not slip) until they are all submerged. A couple days later I use a sponge to remove the excess water (why dry a bunch of extra water when processing) and toss the slop onto plaster. The plaster really helps to keep the clay at an even moisture level, more so than starting from a perfectly smooth slip. 

[Hulk]

Hi s6x, welcome to the Forum!

Good questions.
I don't believe there's chemical considerations, given the clay is nearly the same as it was originally.

Thoroughly dry clay absorbs water quickly and turns to mush, even big chunks, total mush.
Damp clay bits get mushier on the outside, however, the insides seem to stay about the same for a very long time.

I'm storing clay to be reclaimed in two states, totally dry, and slop, nothing in between.
Eventually the slop will dry out to become a disc of dry clay at the bottom of the bucket - even with a lid.

Any road, to start, I'll put the two together, then add enough water such that the dry stuff turns to mush AND the result is wet enough that my grout mixer (driven by a 1/2" drill motor) can turn it without burning up.

I'll run the mixer for a few minutes - not so long that the drill motor gets hot (!!!) - several times/day until the mixture is smooth and uniform.
Ah, there's the point! Smooth and uniform mixture! Then I'm scooping out onto plaster slabs for drying to wedgeable consistency. When it gets there, wedge, bag, go.

Thoroughly dry, so the clay will absorb water quickly.
Mush, wet enough to mix with the drill motor setup.

And finally, whatever works for you!
With stronger machinery, the reclaim process can be done with less water? With a pugmill, the result can be dialed to target consistency, no drying time required?
I believe so.
Surely, a small amount of clay can be reclaimed without any mechanical assistance. I like to use the drill powered mixer.

 

[s6x]

5 hours ago, Min said:

If what you are doing works and is easy for you then there is no  reason to change. 

Some claybodies don't rehydrate well if they are semi dried out so for those it's easier to dry the clay until it's bone dry then slake it in water. Bone dry clay will slake down much faster than semidry clay. A slurry mixed claybody thoroughly wets all the particles so clay made from slurry mixed is considered nicer to work with but if what you are doing makes the clay just as good  then no reason to do anything different.

Welcome to the forum!

Thank you!  I guess what I'm wondering is if even what I think what I"m doing works, maybe if I did it "the right way", I would have less issues when firing or something like that.  

[Min]

1 hour ago, s6x said:

maybe if I did it "the right way", I would have less issues when firing or something like that.  

Don't think so. What firing issues are you having?

[s6x]

14 hours ago, Min said:

Don't think so. What firing issues are you having?

once in a while a piece cracks

[Callie Beller Diesel]

Cracking can have a lot of reasons. If you find your reclaim is cracking more than fresh clay and all other forms of user error have been eliminated as possibilities, there’s 2 possibilities that come to my mind.

First, it could be that the reclaim has more throwing slop/fine particles in it. If there’s no trimmings or dry bits added to it, or you’re just drying the throwing bucket leftovers on the plaster wedging table overnight, you wind up with all the stuff that is plastic, but also shrinks a lot. If this is the case, save your throwing slop to add to larger batches of reclaim. If you don’t wind up with a whole lot of reclaim, you can repurpose it as decorating or casting slip. I know a lot of us feel strongly about waste, but it is ok to discard some in the trash if you really don’t have another use for it.

The other possibility (and I experience this with Plainsman M390) is that it may be a clay body that really needs to be slurry mixed to get useable reclaim. Some clays have a diverse particle mix, and if they’re not blended well, you wind up with issues. 

 

[Min]

2 hours ago, s6x said:

once in a while a piece cracks

There are a myriad of reasons pieces can crack. Forming methods, trimming methods, drying methods, firing methods, glaze reasons, cooling methods and so forth. The go to resource for tracking down and determining why a piece cracked is Frank and Janet Hamer's book The Potter's Dictionary of Materials and Techniques. It is well worth purchasing and comes highly recommended by many people. You can see a snippet of the book and the relevant section on cracks in the link below.

There are over 30 scenarios for cracks.

https://books.google.ca/books?id=TApnGTVLwxAC&pg=PA86&lpg=PA86&dq=hamer+and+hamer+cracks&source=bl&ots=inS6KQPb4N&sig=ACfU3U3-WW9HznLwIEytHMyGanL2bpymZA&hl=en&sa=X&ved=2ahUKEwiG1JCB0KPgAhWyPH0KHX7EBo4Q6AEwB3oECAcQAQ#v=onepage&q=hamer and hamer cracks&f=false

[PeterH]

2 hours ago, Min said:

You can see a snippet of the book and the relevant section on cracks in the link below.

+1 ... but I failed to find the extract on cracks.

In case it isn't just my finger trouble, here is an extract from an earlier posting
http://ceramicsfieldguide.org/pdf/materials-handouts/ClayCracks.pdf