Sticky gunk in rotary

Have you changed the type of rock your tumbling? I've noticed softer stuff makes my slurry thicker. I usually have about the described amount of sticky sludge after a week long tumble. I don't personally think that Borax would help, kinda the opposite. Maybe more water ratio would thin it. Hopefully the others will chime in as well.

Pretty much the same sort of rocks being tumbled  ... common Lake Superior "pretty" rocks and assorted field and river glacial debris types.
The top watery part looks pretty much as it always has but this "settled" stuff on the bottom is puzzling because it's a  horizontal barrel that gets periodically picked up and shaken to keep things stirred up ... especially because nothing in the routine seems to have changed.  

If you have the same sludge, perhaps it's normal and it's been there but I never paid any attention to it.  

Whenever I stop a rolling or vibratory  session, if I am not going right on to  another stage, I wash the rocks really well  and leave them in an ice cream bucket of water .. am that paranoid about "stuff" drying on the rocks. 

Good luck on your cleaning project. May have to go back to a stage one and start over to remove the gunk "patina". 

You rang ?   

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The granite types tend to do fine until the final polish stage when undercutting takes over.

I have learned to love the nooks and crannies as part of their charm  ... since they seem to be unavoidable. 

The part that puzzles me is not so much about the "gunk" itself .... I know that is what is ( I think) colloquially known as "rock snot" and ground to a powder grit  ... but why it is jammed up on the bottom of the constantly rolling barrels even when the barrels have been taken off and shaken to "stir things around" a few times during the week.

NOT a major mystery (or problem) ... more curiosity!

Are you noticing any coarse grit still in the sludge? Not rock chips but actual pieces of sic.

With that being said, it seems as though it must be settling rapidly as you take the lid off of the barrel and not sticking to the bottom. I would think it would trap grit otherwise. Maybe someone else will comment. Hope it helps, I'm still learning as well.

Pouring fresh concrete into water will set just as hard as when pouring a sidewalk or driveway out of water.
So when tumbling concrete chunks the slurry can set hard when the tumbler is turned off for a time. Concrete is fairly soft so it makes a lot of slurry in a hurry. Rocks with high lime content can act similar.

When stopping a rotary tumbler shaping common soda-lime glass in step 1 the slurry can solidify in 10 minutes so hard that the contents must be pried out of the barrel with a screwdriver or similar tool.

If tumbling soft calcite or fluorite rest assured that the slurry will build quickly in shaping step 1. Probably overnite. It is guaranteed.

Tumbling away just the soft lime coating on petrified coral using zero grit because the white lime coating was loaded with quartz splinters formed in the the coral tubes that served well as abrasive. The white 'sludge' about had to be cleaned out daily or constipation(good description) would occur. Going the other way, kaolin based medicines cure diarrhea, kaolin is the byproduct of tumbling felspar and felspar bearing granite.

www.flickr.com/photos/67205364@N06/albums/72157634669474396/



After a few days the naturally stained lime has been removed:

Yes exactly. A thick layer with all the small media imbedded in it. Clearly it took some time to get that way, not just “settling “ for a few minutes.