Reclaim Clay Wedging (cracks?)

[Brandon Franks]

Hey (sorry for all the recent posts, this social distancing has really caused me to focus more on my operations than production)

 

So this has been happening for a while, but I haven't cared because I mix this clay 50/50 with fresh clay, but my reclaimed pugged clay always cracks when wedged. Should I add bentonite to help this? Ill attach pictures but this was put through my pug mill probably 6 or seven times (I don't have a mixing one) its all the same porcelain and it is well mixed through. I would like to throw this clay by itself and start pushing though my like 300lbs of scraps I have sitting in buckets.

 

 

[Mark C.]

Are you adding the fines from your throwing splash pan that usually cures this

[Brandon Franks]

4 minutes ago, Mark C. said:

Are you adding the fines from your throwing splash pan that usually cures this

Fines?

[Bill Kielb]

5 minutes ago, Brandon Franks said:

Fines?

Very fine porcelain trapped in the water of the splash pan. 

[Brandon Franks]

Just now, Bill Kielb said:

Very fine porcelain trapped in the water of the splash pan. 

Oh you're right. I usually just dump that into my slip buckets though, there should be a decent amount of it in these pugs.

[liambesaw]

@glazenerdhas a recipe to add fines back into your clay.  I bet he has a special recipe for you crystalline people but if I remember correctly it's something like a handful of feldspar, a handful of ball clay (or some macloid of some sort) and a handful of 325 silica

[Magnolia Mud Research]

I use reclaimed clay frequently.  Wedging cracks are common. Ignore them! until you are ready to put the lump on wheel to throw, then compress the lump and smooth the surface lumps, ... has worked for me since forever. 
why are you wedging clay that has just been “wedged” inside the pug mill?  Choose your lump, compress into a ball and go to work.

LT

 

[Brandon Franks]

47 minutes ago, Magnolia Mud Research said:

I use reclaimed clay frequently.  Wedging cracks are common. Ignore them! until you are ready to put the lump on wheel to throw, then compress the lump and smooth the surface lumps, ... has worked for me since forever. 
why are you wedging clay that has just been “wedged” inside the pug mill?  Choose your lump, compress into a ball and go to work.

LT

 

Im rocking a 2004 shampoo pug mill! Hasn't seen a vacuum before haha, need to wedge some small bubbles out.

 

Plus I am throwing 6-10 lbs with the reclaim, I find that throwing smaller pieces with it often exposes imperfections.

[CactusPots]

I usually pug wet and age at least 2 or 3 months.  My thinking is that the clay cracks like this because the water isn't sufficiently coating the clay particles.  If I pug to a hardness similar to commercial clay, I get these cracks a lot.  More water and/or more time.

[Mark C.]

If the clay is short -meaning it throws poorly at tall forms and if it really show you cannot pul a tall form- but ok at small forms (thats way they say short by the way)it needs the fines added to straight it out.

All reclaim can benefit from adding the slip (fines from your splash pan). Collect and save it for adding to short clay-it helps kick starting the  age process and you will find if your clay is say cracking when slab rolling it will help this problem. If your clay throws fine and is just cracking during wedging then it's a non issue

 

[Hulk]

Nerd's  reclaim restore recipe copied to this thread (and several other places):

https://community.ceramicartsdaily.org/topic/19047-reclaimed-clay/?tab=comments#comment-149790

...doesn't take much!

My reclaim starts out wet enough such that a grout mixer on a 1/2" drill doesn't bog down, iow, wet, like wavy gravy - takes a few days to dry enough to pile up on plaster slabs, hence, I believe it's fully wetted. Any road, suggest going by how well it behaves on the wheel (and/or your process) over how it looks whilst wedging.

[CactusPots]

My reclaim would take more than just the throwing water slop added to make it have no "short" characteristics.  I gave up on adding extras to the pugmill such as grog, red art, ball clay etc.  I just couldn't figure out anything that was a definite improvement.    My add clay to the pugmill looks like between slip and very wet clay.  When that ages out, it's pretty solid useful product.  I find resetting the top rim at every pull helps working with short(er) clay.

[liambesaw]

I've been mixing my own porcelain for a special project and have found that increasing the veegum-t from 1% to 3% has made a load of difference as far as shortness is concerned.  I was told it is expensive but what I have found is that it is "expensive" but only when compared to other ingredients.

[Babs]

1 hour ago, liambesaw said:

 I was told it is expensive but what I have found is that it is "expensive" but only when compared to other .......

Now I am going to use that philosophy from now on

[liambesaw]

14 minutes ago, Babs said:

Now I am going to use that philosophy from now on

Well it's used at like 1-3% so the 40 dollar bag lasts as long as the 40 dollar bags of kaolin and Feldspar even though it's 1/50th the size

[Babs]

5 hours ago, liambesaw said:

Well it's used at like 1-3% so the 40 dollar bag lasts as long as the 40 dollar bags of kaolin and Feldspar even though it's 1/50th the size

I was speaking of life in general:-))

[Hulk]

fwiw, my reclaim was behaving well enough without admixture, plenty leggy. However, being curious, have added Nerd's mix (less than the min amount) to the last several  batches; the result is creamier, and seems to take a bit longer to dry. Hence, should reclaimed reclaimed reclaim tend to shortness, voila! ...ready for that. Also wanted to test, then report to local JC instructor, for their reclaim can tend toward Lilliputian...

[glazenerd]

Hulk:

Ball clay do more than just add plasticity. Clay basics: ball clay is a 2:1 particle which holds moisture on its inner platelets which extends drying time. Porcelain (kaolin) is a 1:1 particle ( no inner platelet) which holds moisture only on its surface which results in much shorter drying time. The higher the plasticity level of ball clay= the longer the drying time.

[Sorcery]

Forgive me, but in this fast paced world, adding stuff and not waiting seems to create more problems.

Now that we have this time to get ahead of the 8ball, we should.

Get that reclaim aging!

Sorce