One of my favorite parts of teaching people about clay is when we get to talk about waste. Clay is so magical, there is no waste. Potters reclaim and reuse their scrap clay, which is good, because otherwise we'd all be throwing out hundreds of pounds of clay a year. Often potters put it off and end up with a huge unmanageable amount of clay to deal with all at one time. I prefer to keep up with it as I go. I have a lot right now because of all the plates I made..there are a lot of trimmings with plates. Normally I have one mound or two every few weeks.
Here are a couple of ways to reclaim your scrap clay.
1) Wet trimming and collapsed pots.
Wet trimming is where you trim off a little of the extra clay at the base of a piece before you cut it off of the wheel. I often have a huge pile of these trimmings at the end of a throwing session. When I was a beginner, I used to drop these into my throwing bucket to keep them out of the way, but now I keep them at the end of my ware board and rewedge them at the end of the throwing session. It's usually enough to do a bunch of handles. If I happen to have lose any pieces while throwing I add them to the pile and wedge them up.
2) Reclaiming whole pots.
Sometime you lose a piece while trimming. Leather hard pieces don't reclaim as easily as bone dry ones. They always seem to remain stiffer and can throw off the consistency of your clay, which is OK if you have a pug mill, but I don't.
I set them aside to dry out completely, then drop the pot into an empty clay bag and crush it up and add dry trimmings,which leads me to the next way to reclaim...
3) Reclaiming your trimmings.
Bone dry trimmings are the easiest to reclaim. I simply sweep and gather them up, put them into a used clay bag, then pour in the slop from my throwing bucket. If there is not enough moisture to completely cover them I add more from a fresh source to soak the pieces and then pour the excess back into a bucket. I leave the bag sit for a couple of days, then squeeze it all out into a smooth mound onto plaster bats to dry, it usually takes 3-4 days for it to be ready to wedge.
I always run through the mound with a wire a few times before I start to wedge..I occasionally lose a tool in my throwing bucket and it often hurts to find it while wedging. It will also alert you to any moisture inconsistencies.
If you have a batch with harder and softer pieces after reclaiming cut off thin slabs and restack them in alternating directions to manually pug them, slam it down a few times and then do it again, after 2 or three times the inconsistency will be gone and your clay will be ready to wedge and throw.