Re-charging vs starting fresh

Hi GG, I've been playing the same game and never even considered this question before. I hadn't thought there could possibly be a downside to continually reusing the slurry and just adding more grit. Slurry (of even wornout grit) has to be a better medium for the new grit than just water I had thought.

I look forward to the answers from the experts...

Can't wait to see if I'm doing something else wrong!
Could the slurry actually be cushioning the action of the new grit?

I usually will just add grit after 3-4 days starting out, but that onty works once or twice, beyond that you do need to flush out some of the old slurry because when slurry gets too thick it becomes like putty and stuff stops moving inside the barrel altogether.

But I almost never "start over" with course cycles, I always have some old slurry in, even if all the rocks are going in for the first time.

I did 2 recharges today and 1 a couple days ago, so I guess I'll let them run for now. (Still waiting on more replies)

What I did find odd today was in one of my 15#ers (the sodalite) the barrel was almost full. It had been 2/3 to 3/4 full when I did the last recharge 10 days ago. The slurry was quite frothy with air bubbles. I probably wasted ANOTHER week because the air bubbles were cushioning the tumble...?

I added a couple Tums to the recharge, but I can't imagine the sodalite is gassy now after almost a month in the 60/90

Whilst I am still a newbie myself, I do have one large successful
batch finished, and another entering polish stage. I use 2, 12 lb. Lortone barrels on a home-built tumbler.

I charge with 2 TBS 46/70 per pound of stones. I keep 1/3 of the slurry over to start the next batch. I use less water than some, filling the barrel 3/4 full of stones and adding water only until it is 1 1/2 to 2" below the level of the stones.

I believe that it is also important to have a lot of 1/4 to 1/2 " filler (25 percent) I use crushed agate, jasper, tempered glass etc. When I get the slurry just right with the right amount of water and filler, the grit will be gone in as few as three days, so I check the barrels that often.
Bill

Mel, that doesn't surprise me at all. Usually in coarse grind a batch runs until the slurry is thick and needs to be gotten rid of - in effect, until the batch is so contaminated with slurry that it needs changing. If you add slurry to start a batch, wouldn't you just be adding contamination and reaching that end point sooner?

I like to start a batch with less water than recommended so that a slurry forms quickly. Then after two days I open the barrel and add water to thin it out so it can keep going. I do that again at 4 days. I guess everyone has their own method.
-Don

What a wonderful thread!!

I've only been tumbling since mid-June and in January, Bob and I essentially started over with what we laughingly refer to as "Tumbling 102". I have run many loads all the way through to the end of AO polishing but actually ended up with very few stones that I actually deemed "finished". As of January I have become much more aware of many facets of the tumbling process and the question of retaining the slurry versus fresh starts has definitely become a major consideration for Bob and I.

One of the things I am doing with my Lortone barrels that I only started in January is weighing my tumbles each time I take them out of the barrel. Now I have a more accurate indicator as to wether or not there has been a genuine change in the stones.

BUT for our four big Thumler's (each is 15#) we are only running 60-90 grit and doing visual checks. So how do I decided when to recharge and when to dump and start fresh? I guess you could say when the slurry looks like pea soup!!

Sometimes what I do is take out all of the stones very early in the morning and let the tumbler sit with the slurry until late in the day or even over night. If I can see grit particles, Bob gives the barrel a good shaking and stirring and the stones get re-introduced along with a grit recharge. If the slurry is thick like a sludge and the barrel has not be cleaned out for 3 or 4 weeks I take a good look at the stones. If there is little change (I compare weekly photos of each batch) then Bob empties the barrel; gives it a good cleaning; and we start out with fresh water, fresh grit, AND fresh rough chips of mixed agates, jaspers, and quartz. (I got two super-full boxes of great perfect tumble-sized chips from Ralph and Mary Ann (stonesthatrock) in January and they are PERFECT additions to our base tumbles.

The very longest that any one slurry every ran in any of our tumblers was 30 days. As I look back over the logs I've kept I see that typically we change out the Thumler's every 3 or 4 weeks. I have no "scientific" basis but a gut feeling that a successful 60-90 run in our big Thumler's 15 pounders requires a mix of sizes for the tumble stones, clean water at start and as replenish when necessary; a cup of 60-90 to start and half as much for a good recharge; and a nice assortment of small chips added on a regular basis.

In about three or four years I think I will have a much better feel for the "science" of what I am doing with these tumbles. For now I just go with the gut feel and the looks of each load when it comes to the big tumblers.

Now as for the little 3 pounders--that's another whole story!!! ;D


Again...this is a great thread. Thanks for all the sharing of knowledge and experiences!


Lady B

Very interesting replies from everyone. Thanks!

Either jumpstarting the slurry, or recharging... I think I'm keeping too much of the old stuff. I kept a little less on friday, and added a bit more grit, so I'll leave it for now. And change things up on the next check.

I have 4 3lb barrels that I constantly run on coarse grit.
I use 46 grit in each of the barrels
2/3 - 3/4 full or rock and fresh water until I can just see it it through the top rocks

I have found that nearly all of the grit has broken down in 6-9 days. (Every few days I take the barrels off the tumbler, turn them upside down, give them a shake, turn them up the right way, open them and if I can see any grit I put the barrel back on if not, it's time to clean it out)

I do not start with any slurry or use any "jump starting". With the grit breaking down so fast and make a decent slurry so quickly I have no desire to speed up the process.

Mike

For me...the newer the grit...the better it grinds. I do sometimes keep a little old stuff but if I had to guess at percentages...it'd be 25% or less of old.

A couple of things off the main topic but brought up: Foam...don't worry about it. Sometimes you have some...sometimes ya don't. If it doesn't build up enough to pop yer lid off, I'd say let it go. I know others have used tums but for me...putting a teaspoon or so of borax in each every one of my barrels with the grit helps to keep foam down plus you get the added benefit of it acting as a carrier of the grit.

One of the things that REALLY surprised me was the different colors you can get of your slurry depending on what kind of rocks you tumble. Grey, brown, tan, bluish and the surprising red!