Stinky Mold in my clay & throwing water

[rdroza]

Hi Everyone, 

I'm a newbie potter & just set up my home studio,  I've just finished my first recycling of clay, which I wedged & put back into storage for throwing. Today when I opened my clay to wedge & throw I noticed black veins in my clay when I cut it. I figured I had not let my clay dry enough before I put in back in storage & hence mold appeared. I also noticed that the container which I store my throwing water in has a thick layer of black mold at the bottom.  I checked online on what to do to address this, but couldn't find clear guidance. Various forums state that Epsom salts or hydrogen peroxide would help, however I'm not sure how much I should use for what quantity of clay.  Would anyone here be able to advise me how to clear the mold from my throwing water & clay? I can't stand the smell 😕

I'm using a white stoneware clay body and approx 7 Kgs of Clay.  

Thank you in advance

Regards

Ruth

[Callie Beller Diesel]

ah; the stink of reclaim! Yep, it’s gross. 

The black streaks are nothing to worry about. They don’t hurt the clay and it’ll burn out in the kiln. Don’t worry about trying to remove it from already wedged clay.  

For the throwing water, we’re probably going to tell you the same thing as Reddit and other replies on this forum. There isn’t really a measured amount or proportion of peroxide or bleach to add. Start off with a small splash, (a few tablespoons) and add more later if it still stinks. 
Some of that is because the quantity needed will depend on how much mould is in there, what you use and how mould friendly your conditions are. 
 

I wouldn’t use Epsom salts: I don’t think it’s particularly antibacterial. I favour peroxide because it breaks down into water, but if I don’t leave my reclaim sitting long, I don’t have to do it much. 
 

 

[Magnolia Mud Research]

One way to manage the stinky mold is to stick a couple pieces of copper wire (or use a copper container) in the slip and water (or hang Copper Pennies).  Most molds don't like copper. 

[Min]

52 minutes ago, Magnolia Mud Research said:

One way to manage the stinky mold is to stick a couple pieces of copper wire (or use a copper container) in the slip and water (or hang Copper Pennies).  Most molds don't like copper. 

This is such an interesting thought. Have you tried this?

[Magnolia Mud Research]

yep!

long ago the family was going to grow molds for some reason.  The setup was using a network of pipes that were connected with copper joints.  The joints killed the molds; took some time to realize that the joints were the problem.  When I was told why the molds died I started using copper wire stuck in the clay; the old mold died, and no more came back.  

 

[Min]

2 hours ago, Magnolia Mud Research said:

yep!

long ago the family was going to grow molds for some reason.  The setup was using a network of pipes that were connected with copper joints.  The joints killed the molds; took some time to realize that the joints were the problem.  When I was told why the molds died I started using copper wire stuck in the clay; the old mold died, and no more came back.  

 

So in theory when people had new copper plumbing they would have less bacterial growth in their reclaim? Time for a test, thanks for the idea.

[Callie Beller Diesel]

I’m very intrigued by the copper thing, and I just so happen to have a bent piece of copper pipe and access to a number of barrels of reclaim to test this on! 
 

gimme a week and I’ll report back. 

[PeterH]

> One way to manage the stinky mold is to stick a couple pieces of copper wire (or use a copper container) in the slip and water (or hang Copper Pennies).  Most molds don't like copper. 

Just to point out that the amount of copper in "copper" coins has dropped over the years, and it's bioavailability has probably dropped even more. However a more recent shift has been towards base-metal coins electroplated with copper. Where the limited copper should be highly bioavailable again.

http://www.americanplatingcompany.com/copper-in-a-penny/
The first change came in 1856 when the “Flying Eagle” scent started production with of 88% copper. In 1864, after the Civil War, the design changed again with a 95% copper 5% zinc make-up. Finally, in 1982, the coin would evolve into its modern form of only 5% copper and 95% zinc. The modern penny has the least amount of copper with a small 2.5% copper plating and a 97.5% zinc base.

https://en.wikipedia.org/wiki/Penny_(British_decimal_coin)
The coin was originally minted in bronze (composition 97% copper, 2.5% zinc, 0.5% tin) between 1971 and September 1992. However, increasing world metal prices necessitated a change of composition. Since 1992, the coins are minted in steel and electroplated in copper, making them magnetic.

Edited June 8 by PeterH

[Morgan]

It’s not good reclaim if it doesn’t have mold! I’m kidding but part of me wants to think it helps somehow haha

[oldlady]

reclaiming clay with water seems so unecessary to me that i wonder why people do it that way.   i guess if you learned in a shared studio where there is always a big container of wet clay you just assumed it was the only way to work.

i normally dry out all the clay left over from a day of working either slab or wheel.  slabs are so easy because they are thin and can dry overnight.  wheel is also easy because i throw nearly dry anyway.   i do NOT believe the nonsense that a pot must have at least a 1/4 inch thick wall so i am working with less clay.   faster also  because of no water is tossed by the gallon into the spinning pot.  theneed for water is only between your finger and the clay.  the less mess you make the easier it is to keep your studio clean.

let the thin clay dry on drywall which absorbs some to the wetness quickly.  when you have accumulated enough dry clay to recycle, drop it into a bucket, breaking it even more and add enough water to cover the top pieces.  overnight it will absorb enough water that you can pour off the excess and start working with "new" clay.  there is no plaster in my studio.

throwing water can sit in the container overnight also and the watery part can be applied to plants or lawn just outside.   the stuff in the bottom becomes slip to be sieved into a bucket.  slip is only wet, very wet, clay.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[Callie Beller Diesel]

Fun fact: Canada doesn’t make pennies anymore, although ours were all copper. 

[rdroza]

Thank you everyone for the help! I've bought a meter of copper wire and dropped it in the mouldy water. It's been 3 days & I don't see a change as yet,  but will give it 10 days & then figure. If it doesn't work out, I might try hydrogen peroxide. Will report back on my copper experiment  I've been taking photos too, so will share as this experiment progresses.

[Hulk]

I gave the red clay slop bucket* a squirt of hydrogen peroxide a few days ago. The clear(ish) water portion, much improved for a few days, however, the clay portion about the same stinky, and the clear portion, well, I skim it off periodically... ...mixing the peroxide about would likely help - I'd tried that, early on, but have just let it stink since, for once the reclaim process is well along - to the point where almost ready to ladle out on plaster - then stink retreats.
 

*Most of the reclaim gets thoroughly dried out. The throwing bucket slop goes to a settling bucket, where it will eventually dry out if left undisturbed long enough and become a dense disc.

[Min]

45 minutes ago, Hulk said:

I gave the red clay slop bucket* a squirt of hydrogen peroxide a few days ago. The clear(ish) water portion, much improved for a few days, however, the clay portion about the same stinky, and the clear portion, well, I skim it off periodically... ...mixing the peroxide about would likely help

Hydrogen peroxide works but there has to be enough of it to do it's job. I would suggest pouring off the water so you just have the sludge remaining then stirring in the H2O2. If it doesn't (quickly) work then stir in some more. My throwing slops are in 750ml yogurt containers, if it starts to smell I'll use about 50mls of H2O2 in about a 1/2 a container of sludge.

[Hulk]

Yep, allow to settle and take off the clear portion, then, without there's "enough" H202 to fully clear the stink, it will just be not as bad for a while, then recover its full form after not very long.
The other point, the smell recedes and clears as the clay reaches (dries out) sticky to "almost there" status.
That's been my experience.

I was curious how much help a small squirt would be - would it take the edge off? For a few days.
It's getting to be Summer 'roun' here. The floor mop and throwing water buckets get yucky fast!