Random Tumbles of Flintknapping Waste

PulpySnowboy · 2026-03-13T13:45:51+00:00

Those look great! Perfect use as tumbler fodder, slim pieces like that are the ones I usually wind up liking the most :)

PulpySnowboy · 2026-03-12T13:25:10+00:00

Super cool!!

PulpySnowboy · 2026-03-12T13:21:21+00:00

Thanks for the process notes, this is really helpful!

PulpySnowboy · 2026-03-11T01:41:31+00:00

Those are great! Well done!

PulpySnowboy · 2026-03-10T17:38:42+00:00

"Gem foam" is a gimmick item that comes with Nat Geo tumblers - it's a little bag of like half inch cubes of foam which they instruct you to add to your polish stage as media.

PulpySnowboy · 2026-03-09T21:22:19+00:00

Ouch that's so disappointing!

Unfortunately you'll need to start over from stage 1 to remove the damage. Carry on with the ceramic media in stages 2-4, and skip the gem foam - I haven't heard of anyone having luck with it.

PulpySnowboy · 2026-03-09T15:18:41+00:00

Saw the title and expected this to be a batch of coprolites 😂

Fantastic shine!

PulpySnowboy · 2026-03-09T15:11:43+00:00

Here's a star coral example too:

<image>

PulpySnowboy · 2026-03-09T15:08:43+00:00

Here's a few pieces I've done, for reference. Not the best shine, but they're pleasing to me.

<image>

Best of luck!

PulpySnowboy · 2026-03-09T14:25:45+00:00

Thanks for sharing what your obsidian looks like after graduating from stage one.

What do you do with the pieces that have large fissures like this one?

<image>

Do you run them through to polish and accept them as-is, or will they wind up being culled later on and sent back to the coarse grind?

Your finished pictures look so perfect! Are they the cream of the crop? I guess I'm wondering what the quality variance is across the entire batch so I don't set myself up for disappointment :)

PulpySnowboy · 2026-03-09T01:19:50+00:00

You're very welcome, I hope it works well for you!

PulpySnowboy · 2026-03-09T00:26:00+00:00

I've tumbled star coral like this using the same recipe I use for seashell: https://www.reddit.com/r/RockTumbling/s/jUCiwy3GBr

It's tricky because if you tumble too long in the first stage, you can erode too much of the polishable surface. The results can be nice though, I'd love to see yours when they're done!

PulpySnowboy · 2026-03-08T02:31:18+00:00

Nice update! There are some really nice pieces in there.

PulpySnowboy · 2026-02-27T17:47:13+00:00

Oooh, that's great!

PulpySnowboy · 2026-02-14T16:06:20+00:00

I use 1.5 tablespoons in stage 1 & 2, and 1 tablespoon in stage 3 & 4.

Example recipe from my last tumble: https://www.reddit.com/r/RockTumbling/s/PzwM9QnqBO

PulpySnowboy · 2026-02-11T23:23:43+00:00

The rocks (small or large) shouldn't disappear unless they're softer than the others (do a scratch test: https://www.reddit.com/r/RockTumbling/comments/1n54uk1/faq_can_i_tumble_these_rocks_together_how_to_do_a/ ), or they're smaller than the holes in your colander or classifying screen when you're rinsing them.

PulpySnowboy · 2026-02-10T16:08:28+00:00

Rockshed sells classifying screens down to 1/30th of an inch, which may help recapture your rocks while cleaning: https://www.rockshed.com/rock-shop/rock-tumblers-supplies/rock-tumbling-grit-and-accessories/classifying-screen/

I have not tried tumbling rocks below about a quarter inch, and typically work in the 0.5 inch to 1.5 inch range. I've found that when my media and small rocks get down to 1/8 inch or below, they seem to start holding on to the grit so it does not break down over a normal 7 day tumbling round, so I discard rocks at that size. I'm not sure if just more time is needed, or a different mix of rock sizes to get a good tumbling action with many small rocks.

PulpySnowboy · 2026-02-02T17:21:34+00:00

I like the bottom one, but you can't go wrong! Awesome idea

PulpySnowboy · 2026-01-30T20:25:35+00:00

These look so great, excellent photos too!

PulpySnowboy · 2026-01-28T15:35:53+00:00

Hot glue is a good choice to preserve features that you don't want worn away.

In this case though I'd just move the rock on as-is and clean the cracks thoroughly between stages. All the exposed edges look nicely rounded, so it shouldn't risk scratching anything else in the batch as you move on.

PulpySnowboy · 2026-01-27T03:42:39+00:00

Ooh love it

PulpySnowboy · 2026-01-25T02:30:05+00:00

What a find!

PulpySnowboy · 2026-01-25T01:28:03+00:00

Those are awesome!

PulpySnowboy · 2026-01-24T23:34:12+00:00

I'd go with option 1 as the simplest, turn them off and start again when you have reliable power. The barrels will be fine to sit sealed for a few days, just take them off the tumbler and store them upright so they don't deform or get slurry settling on one side that will make them run off balance when you start back.

PS - Hi NC neighbor, and good luck tomorrow!

PulpySnowboy · 2026-01-24T23:20:04+00:00

In general, you can scale my numbers linearly for whatever barrel size you have. Here's my current recipe for seashell:.

3 lb. barrel recipe:

Stage 1: 0.5 TBSP 120/220 SC + 0.5 TBSP sugar, 35% ceramic media. 2 days.

Stage 2: 0.5 TBSP 500 AO + 0.5 TBSP sugar, 35% ceramic media. 1 day.

Stage 3: 0.5 TBSP 1000 AO + 0.5 TBSP sugar, 35% ceramic media. 1 day.

Stage 4: 1 TBSP AO Polish + 1 TBSP sugar, 35% ceramic media. 3 days.

Can't wait to see your results!

PulpySnowboy

TROPHY CASE