There are a number of video clips on YouTube about tumble polishing stones. This one, “The art of stone tumbling and polishing”, two minutes long, while it includes some good advice and shows the main steps involved, also conveys some misleading impressions:
1) This guy does it one-handed – you actually need both hands to do it well! (So when you make a video of it, it’s a good idea to get someone else to film you doing the demonstration.)
2) The number of stones he puts in the barrel, and the amount of water poured into it, is probably too much – most guides say fill the barrel about 2/3 to 3/4 full.
3) It’s not a good idea to let silicon carbide grit blow about in the breeze. It’s tiny and hard and sharp and you don’t want it to get into other stuff. It can do damage to a washing machine if it gets onto your clothes which are then washed.
4) He puts about one tablespoon of grit into what looks like a standard 3 pound barrel – there are different views about how much grit to use – a reasonably standard view is that you should use four tablespoons for this size barrel, some say half that, others say weigh the stones and put in a certain amount per pound of stones, and so on. You need to do your own research on this and maybe experiment with the amount.
5) “Secure lid on drum” – excellent advice, but this is not well demonstrated visually, given the one-handed approach. An insecure barrel lid is asking for disaster and the need for a clean-up.
6) “Pour off waste” after tumbling for seven days – yes, but make sure the waste does not end up down the drain where it is likely to accumulate in plumbing s-bends due to its weight and then set like concrete due to its composition! This is deemed by all leading instructors to be the most important piece of advice about tumble polishing stones.
7) “Tumble and wash each grit as before” – though sometimes you need only 3-5 days with the stage with the finest grit or a pre-polish powder, and the last stage involves a polish like tin oxide or cerium oxide.
It’s actually a great little video clip and gives me the opportunity to raise these points, all of which I am sure are well-known and appreciated by the video-maker.
