plastic pellets

[181lizard]

So I know why we use pellets. anyone out there used anything slightly unorthodox? Had better results with anything else?

[entrerh9]

181lizard,
Well, I use, of all things, rocks! This method takes a lot of patience and work, though, in measuring out and distributing the pieces. Here's how it works for my little 8oz. tumbler, but the method can be adapted for any size tumbler.
I put together a pre-arranged mix according to sizes of the rocks. The number of pieces double each time I move down a size. Here's the "recipe"...

>1 1&3/4" to 2" rock
>2 1&1/2" to 1&3/4" rocks
>4 1&1/4" to 1&1/2" rocks
>8 1" to 1&1/4" rocks
>16 3/4" to 1" rocks
>32 1/2" to 3/4" rocks
>64 1/4" to 1/2" rocks
>128 1/8" to 1/4" rocks

For the stuff under 1", I use just about any kind of rock as filler. The harder pieces remain while the softer pieces grind away (oftentimes to nothing) and in the meantime serve to buffer the batch. There is always enough smaller material left to buffer the batch and keep the pieces smooth and scratch/chip free. You get the added bonus of getting more polished rock per load, and a greater variety of sizes.

[LCARS]

I recently raided a backfill pile of nicely graded bassalt type gravel to use as rough filler. All the pebbles range in size from 3/16" to 3/8" and are edgy & pointy which is perfect for the grinding phase. For fine fill I use beach pebbles & pass them through a grading mesh to sort them by size. It's actually time for me to go back out to get some more.

If you are rich & lazy, go to the pet store & by bulk uncoated silicate aquarium gravel. It is almost always softer than the rock you are tumbling so it will melt away fairly quickly leaving you with a nice thick buffered slurry

[entrerh9]

also...
I run the mix through a pre-grit tumble stage to allow some of those softer rocks to begin their breaking up get the smoothing process of the harder rocks started.

[Jack ( Yorkshire)]

Hi All,
I always throw in all my off cuts& run them through if they are soft they weardown quicker and give a good "goop" breakages also go into the batch from rough I take out sharps and roughthin edges fron 2 nd stage on --

I find small stuff helps a lot

jack
Yorkshire UK

[Cher]

Some use the small ceramic pellets, some have tried pieces of leather, I can't even remember what others have tried. I use the plastic pellets for two reasons. 1. They float, easy to separate from the rocks. 2. They are reuseable many many times over, just be sure not to mix grits with them.

[181lizard]

The reason I asked is cause when I told a gentleman at my rock store about some interesting plastic green pyramids I found he said they were for a vibe, not tumbler. (well so what? I was thinking. Wouldn't they cushion in a tumbler too?) but being so new, I didn't want to get into some big debate right then, so figured I'd ask here to all yous guys.

I've read here before about leather. Seems like it could tend to stick to barrel sides when slurry gets to be proper viscosity.

LCars...the aquarium gravel...is it more expensive than plastic pellets? I've used them so far & had good results. Also, as Cher said...they're pretty easy to reuse & seem to last fairly well.
Would love to have the time to sift beach stuff, but right now logistics & time factor hold me back.

But here's one more thing the guy at the rock store said...

Got 2 different types of stage 4. His type was slightly yellow. The other from another store was more white. I started with his & after about 10 days...I still didn't see the type of finish happening I wanted. (First batch of stage 4 I did was with the white stuff. Great polish after just a handfull of days) Told him about it, that I wasn't crazy about his stores stage 4. Funny how I switched to the other polish & within 1 day, started to get a real nice shine on em!

Long story short...he told me it's very important to keep rock type & size in same batch. Softer rocks could contaminate barrel quality.

Weeeelllll...that's not exactly what I'm reading here with yall! Besides, I pick up alot of rocks in my area & bring them home to tumble. (Quite a few jaspers & agates among others) I don't think he was trying to tell me this just to defend his stores polish...I really think he's the meticulous, everything must be just so, type. Me?...well I'm the "fly by the seat of yer pants" type of girl.

So please send your thoughts about the above to me. Am waiting with fish breath.
(Ya know...baited. hahaha)

thanks yall!

[greenmann]

well, for course I don't use anything for cushion, just try and make sure I have lots of little rocks in with the bigger ones. As I get on, I start using more and more pellets (each kept separate for each different stage). I would love to try the ceramic, since a lot of my beach rocks seem to have indents and divits that don't get smoothed out, and i keep wondering if the ceramic media would grind those areas better.

As far as the fellow at the rock shop is concerned... well, the lady at the one closest to me, when I said I was doing "mixed beach rocks" said categorically most of those don't polish. Well, maybe I have been lucky in the ones I have gotten, but most of them HAVE polished, some to as nice a shine as your typical agate and jaspery type stuff. Sometimes these folks know SO much that they haven't taken the time to experiment with stuff someone else said won't work. Or maybe they just simplify things when asked silly questions by obvious newbies? *shrug* But then, I'm the type that tends to try things anyway, just to see what they do. Speaking of which, need to get the basalt load out of burnish and on to final polish today

[entrerh9]

Would "soft air gun pellets" work as well as the "official rock tumbling plastic pellets"? They are cheap and easy to come by.

[snowdog]

some of the odd shaped pellets have grit made right in them --and according to what shape they are may depend on the grit --check out the "vibra finish " ad at the top of these pages to see ceramic and plastic pellets --they have several different ones listed--cylinders, triangles, etc.
as far as what I tried ---guess about anything except a pound of hambuger---chopped up plastic, styrofoam(the white beady kind),sponge ,cardboard,etc.---most only disintegrate to mush ---but sometimes on real soft stones this is what you want so they don't fracture too much
on the stage four ---I think what you are talking about is cerium oxide (as a polish)--there are several different grades of it just like the grits, the yellow or tan tends to be courser ground while the white may be an optical grade---so the finer you put in, the faster it will bring out the shine --the courser stuff will break down over time but who wants to wait !!

[Alice]

entrerh9 said:

Would "soft air gun pellets" work as well as the "official rock tumbling plastic pellets"? They are cheap and easy to come by.

they should work, but I'm thinking that they may also rust.

Unless your plan is to get rust spots on your rocks, I wouldn't recommend it.

[entrerh9]

Soft air gun pellets are plastic, so there would be no rust problems. Soft air guns do not shoot the standard steel "BBs", they shoot plastic "BBs".

[entrerh9]

also...
these plastic "BBs" are slightly larger than their steel counterparts. Probably would make good tumble cushioning.
In the aforementioned "recipe" that I posted on this subject, I'm finding that I'm starting with a decent looking batch that tumbles down to just a handful of mostly little pebbles, with only a few decent sized rocks to brag about. Due to the limitations of an 8oz. barrel, I cannot simply double the size of the batch with a 2" to 2&1/4" rock being at the apex of the recipe. I think I will try simply adding two 2" to 2&1/4" rocks to the batch and see if that doesn't help improve end results without overloading the tumbler.

[entrerh9]

I found that that original "recipe" does not allow room for two 2" to 2&1/4" rocks initially. However, it does after the pre-grit "pre-grind" that I always do. I added 2 river-smoothed ones last night to a batch already partway through grit stage 1 and it seemed to work fine.

[USMC15]

Refreshing this thread because someone asked about it.

lynn59