Calling all rock tumblers! Tumbling 101 input is needed!

[Tommy]

The RTH Forum community is a vast wonderland of thoughts, experiences, advice, tricks and tips, instructions, lessons learned, and ... on and on. It is our strength and also our weakness because with a few exceptions, most of what has been published on this forum is scattered and hidden by time and difficult to consolidate.

This thread is an experiment of sorts - I'm calling it volume 1 of an information gathering exercise from which a consolidated informational post will come and if it goes well a peer reviewed article thread will result.

The Vol 1. subject is general preparation for a rotary tumble run. Please think about this like I am a newcomer to rock tumbling, I have my very first rock tumbler, and all I know is I'm super excited to transform some rocks.


Guidelines - please follow these simple guidelines and lets see how this goes. Let's keep this on a fairly high level on the subject of initial preparation and once it has ran it's course I will post subsequent threads diving deeper into the technical stages of tumbling, recharging, burnishing, cleaning up, etc.

Post any general instructions or advice, grits to have, startup recipes, rock types advice, tips, tricks, cautions, etc. Anything that you use or think about when preparing and launching a new rotary tumble run - without being personally specific to the size or model of the tumbler you are using if that makes sense.

Don't worry about or debate what anyone else has posted - differences in opinion or redundancy is OK this will all be sorted out later. It doesn't matter if we get the same concept posted twenty times - that just shows that it is something that needs to make the final article.

Try to structure your post(s) in short and concise one or two sentences resembling this guidelines list, that are easy to read and glean information from. Post as often as possible as new thoughts come to you.

No questions in this thread please - lets try keep this thread clean and flowing and free from chit-chat as much as possible.

If you know of an RTH Forum original post similar to this, or you know that you recently dropped some pure gold nuggets of information in a different thread, please post the link as part of your submission, or even better, copy and paste parts of the contents (even if it wasn't your post) and let us know what thread it came from.

Please no copying and pasting from website articles from other websites outside of the RTH Forum. I want this to be entirely organic from the minds of our community.

Thank you everyone!

[Tommy]

I'll start this going with an example that came from original RTH website that went away when the site changed hands. Heavy editing is called for but you get the gist.

Placing your tumbler in a location where it cannot be disturbed, is safe, and cannot be heard is essential! Choose a place where it will have a constant power supply, no children can tamper with it, and the noise will not disturb you or your neighbors. I am fortunate in that I have a garage with a dedicated workbench. My tumbling machines can sit and make as much noise as they will - and do! - without causing a disturbance.

I have soundproofed an area of the garage to protect neighbors from the noise, which although it is not loud, it is very persistent, running 24 hours a day 365 days per year. In the dead silence of the night, it can be heard slightly without the soundproofing.

You should have 4 barrels - Mark one barrel as "80 Grit" one as "220 Grit" one as "400" Grit and one as "Polish Only".

Before you can start to tumble the stones you have chosen, you must first of all break them up into a mixed sized set of pieces. Every tumble you start with should have a good range of rock sizes in the mixture. The reasoning behind this is as follows :-

a) If all the peices are the same size, there will be large "gaps" between them in the barrel as it turns. This reduces the effectiveness of the grits, as there is much less contact between the pieces if there are no smaller stones to fill in the gaps and help with the grinding.

b) The pieces will not "tumble" as much in the barrel, they will tend to settle into a regular "rise and fall" routine which will cause certain edges to be in constant contact with the inside of the barrel wall. Eventually "flats" will form whereby one side of the piece will be the same shape as the inner curve of the barrel and the rest of the stone will be virtually unchanged.

Given a 3LB barrel as an example, you should aim for pieces ranging from just 1mm in diameter to around 3.5cm in diameter with every conceivable size in between!! This will ensure maximum contact with the grits - do not be afraid of having too many smaller stones - these will help form your prize pieces faster and to a higher standard of shape.

WARNING : When breaking up the stones - always wear protective goggles and wrap the pieces up in leather or towels before striking them with a hammer. Not only will this protect you from flying shards (many semi-precious gemstones virtually explode when hit hard enough) but you will also trap all those tiny pieces which are so essential for perfect results.

[jasoninsd]

Great idea Tommy!

- Organize your material to tumble into like hardness, so you're tumbling material that has a compatible Mohs hardness.

[JBe]

-Regardless of what the instructions that came with your rotary tumbler may say, the first stage can be repaeted for a given stone until the overall shape is what you're looking for and/or all of the pits and imperfections have been removed. Keep in mind that the overall size of a stone will be reduced to the depth of the deepest pit on the stone.

[saxplayer]

Saving a spot for later...

[brybry]

Do not buy grit kits that are labeled Stage 1 through Stage 4.

Grit from reputable dealers will be labeled by type & size of the grit, ie ...

80SiC / SiC 80
60/90SiC / SiC 60/90

AO 500
AO 14000

You will use the most grit in Stage 1 for shaping and rounding.
Less for Stage 2 etc, etc.

[catskillrocks]

This is a mohs hardness scale, click on link:
link

SiC = Silicon Carbide
AO = Aluminum Oxide

[amygdule]

Do Not let the slurry dry on your rocks during cleanouts !

I pour my barrels of tumbled rocks into a tub of warm soapy water
Swish them around by hand, gather them up
then rinse them off with clean water

[Son Of Beach]

A couple things I've learned is to get your levels at a good spot. A tumbler too full there isn't enough room for movement, too little rocks you'll get excessive chipping and bruising. I shoot for 75% of a barrel capacity but you get a feel for it. The weight of barrel, like 3, 6, and 12lbs are kind of misleading.  You want consistent volumes not weights. Second I've learned to do my water level before adding grit. Ideally you are shooting for just enough to carry the grit but not so much that it's a swimming pool. Maybe 1-1.5 inches below your rock level. Adding the water first lets you adjust if you overfill. Not as easy when there is grit already in the tumbler.

Couple other things I learned from mistakes.  Always good to check after about 15 minutes to make sure you've sealed your tumbler correctly, that should give enough time for any leaks to show.

Also, give it an honest week before you decide to change out your slurry.

Cheap tools that I've found handy: Set of dental picks for tough to get grit, old toothbrush, cheap loupe, and a canning funnel.  Dollar store or Harbor freight purchases.

[lordsorril]

It is easy to get discouraged when trying to tumble soft stones. 
Agate and Jasper are good beginner materials:  Practice on these until your skills are polished (pun intended).

[perkins17]

Just going to start from the beginning here. When you first get your tumbler, you will need to oil the bearing to make sure the shafts spin freely. I use 3-in-1 oil for mine. Next, selecting your rough: for your first batch, I recommend hard stones, such as a agate or Jasper. Fill your barrel to around 3/4 full (no more) and add water to about 2/3 the level of the rocks. Add your grit, for whatever stage you are in, seal the barrel, making sure there is not grit/dirt on the lip. Put the outer lid on, washer, and nut. Tighten the nut so that the lid is firmly on, but not so much that the inner lid is warping. Then, shake the barrel from end to end to make sure the grit is dispersed throughout the tumbler. Put the barrel on the tumbler chassis and let run for desired time. Hope that is a worthwhile contribution.

[susand24224]

Not all rocks that are the same Mohs hardness are created equal. If you want to avoid chipping, internal fractures, etc. with such rocks as amethyst, rose quartz, etc., do not mix them with jaspers and agates. Equality of hardness is important, but equally important for a super batch is equality of brittleness. Also, if you are breaking up large rocks to tumbling size, avoid smashing (especially the more brittle ones) with a hammer. Better to chip pieces off--less internal fractures.

[Tommy]

Thank you everyone I know I shouldn't be at this point, after seeing it over and over thru the years, but still I'm blown away with the pearls of wisdom that have been shared already. Stuff I never would have thought of in a million years. Please keep it coming!

Anyone with a website could write a "how to tumble" article - I could do it myself - but what we are creating here is on a whole nuther level of knowledge through experience.

I know I aimed this at general prep for a new run but please feel free to veer into mid-cycle and even finishing tips and tricks if you want.

[fernwood]

If you purchase an inexpensive or used tumbler, check the belt. I replaced the belt that came with my Chicago Electric tumbler with an O-Ring from the hardware store. It has yet to be replaced, after 5 years of almost constant tumbling.

When oiling bearings, use a fine oil, such as carbine or sewing machine.
I received the above advice from a RTH thread.

[dillonf]

Thank you for this post, and thanks to all the contributors. It is very helpful to a novice like me whose ambitions are far greater than his skills!

[nursetumbler]

Mar 26, 2022 7:16:45 GMT -5 dillonf said:

Thank you for this post, and thanks to all the contributors. It is very helpful to a novice like me whose ambitions are far greater than his skills!

dillonf
AMEN to that. 👏

[perkins17]

The best grinding/polishing grit I have ever bought came from the rockshed. That is where I reccomend you go if you are new. Tumblers nowadays are often sold with "polish" that does absolutely nothing. Contamination between stages can be an issue with tumbling. Each time you finish a stage, Hose down the rocks, barrel, and lid, making sure that as much grit as possible is washed away. None should be visible after this. Follow my instructions from the previous post to refill the tumbler, and let us run again.

[quartzilla]

Seems obvious but the adage “ trash in trash out” is always appropriate and good to remember. I love tumbling my finds, which is fun, but my best stones are nearly always purchased tumbling rough. A mix of finds and purchases in each run covers both of my tumbling cravings.

[Benathema]

Plan for how to handle barrel clean outs. A 5 gal bucket and some dollar store strainers are a good start. The initial dump and rinse of your barrel needs to be captured, not go down the drain. Some folks dump their slurry on their gravel driveway, but if that's not an option it can be discarded with the weekly trash. You can decant off the water, let it dry, then bust it out to toss it. If drying isn't an option, then scooping the clay-like slurry into empty containers, such as coffee cans works. Just tie it up in a bag before setting it in the garbage can so it doesn't make a mess if it pops open.

Clean the mating surfaces of your barrel and lid gasket immediately after dumping the rocks out. These are the critical surfaces that interface to create a good seal. Place some sort of catch pan under you tumbler when it's running to capture the mess in the event the barrel pops open.

[susand24224]

With permission to move into polishing stage, I *always* use a dedicated barrel (even in the vibe) and always do a pre-polish wash (actually, I often do this with every stage). Put a TBS or so of a mild laundry detergent with no additives, or shave off some ivory soap, into the barrel. For the wash, add more water--since the purpose here is to clean any leftover grit, etc. off, rather than create a proper tumbling action, it should slop around in there. Likewise, after I am satisfied with the polish, I either (a) do a final wash, (b) stick the rocks in a jewelry cleaner, or (c) both. This will avoid those annoying white streaks that lodge in the cracks you didn't know you had--until they jump up and say "hello."