The majority of Batch 27’s stones hail from Gemstone Beach (collected on 27 May) and from the redo holding box (probably Gemstone Beach as well). I am not 100% convinced that using pellets to “cushion” Stage 3 is useful so during this batch I’m experimenting with no pellets in the 400grit tumbling stage.
What is also different about this batch is instead of using Tumble Polish Mix I’m going to be using Tin Oxide for the final polish. Tin Oxide is supposed to be a superior polish finish so I’m curious to see how much better it is than the Tumble Polish Mix – my usual go-to. It certainly is the cheaper option of polish. Tin Oxide is a high polish finishing compound and at $$67.70 per 250g (rather expensive) compared to $14.40 per 250g for the tumble polish mix, I am expecting to see a noticeable difference in shine! Keep reading to see if that’s the case!
Batch 27: 3lb Tumbler 2
Stage 1: 80/100grit
Number of Stones: 53
Weight in: 951g
4 Tbspns of 80/100grit – no pellets
Days Tumbling: 10
Weight out: 832g – loss of 119g
Stage 2: 220grit
Number of Stones: 48+10
Weight in: 970g
4 Tbspns of 220grit – no pellets
Days Tumbling: 10
Weight out: 852g – loss of 118g
Stage 3: 400grit
Number of Stones: 58
Weight in: 852g
4 Tbspns of 400grit – NO pellets added – trying this
Days Tumbling: 11
Weight out: 701g – loss of 151g
After checking the stones thoroughly after Stage 3 (400grit) only one greenish stone has a small pit. 3 stones were removed and placed in the redo box and after the soap tumble prior to polish, one more stone was removed from Batch 27. 54 stones were put in the “waiting to polish” holding box because the 4lb tumbler isn’t free yet.
Batch 27: Pre-tumble
After Stage 1:
Transfer to 4lb Tumbler
After spending a short time in the “Waiting to Polish” holding box, Batch 27 joined some stones held over from batch 28 and stones from batch 29 in the 4lb tumbler. This polish stage is a little different as I’m experimenting with Tin Oxide for the polish stage rather than the usual tumble polish mix from Rotorua’s Rock and Gemstone Shop.
Stage 4: Tin Oxide
Number of Stones: 85 + 43
Weight in: 1941g
Tin Oxide (first use): 8 Tbspns of tin oxide with 600mls of clean water. 14 tablespoons of pellets added.
Days Tumbling: 11
Stage 5: Burnish
2 Tbspns of Borax to clean and clear any remaining polishing mix. Pellets added.
Days Tumbling: 3
Reflection
I have to say when I looked closely at this polished batch (stones from Batch 27-28-29) I have to say I was really disappointed. So many stones had chips and cracks. I thought that I had carefully checked all stones before putting them into the polish but it looks like I wasn’t thorough or as discerning as I should have been.
Tin Oxide is a premium polish too and I know I had high hopes for a “glorious” polish of all of the stones which just added to the disappointment. In hindsight perhaps I overloaded the 4lb tumbler. It did have 128 stones in it which is quite a lot! When I look back at my log most other polish batches have been about 96-103 stones. Perhaps I didn’t have enough pellets in there as well to help cushion the load and that’s why there’s so many stones with pits (or gouges). There wasn’t much room as I recall for a lot of pellets.
The result is most of this original batch (27) and it’s partners from 28 and 29 have gone back into the holding box for redos at either 80/100grit (right back to the start) or 220grit. I’ve just finished sorting through them all and placed them in the best redo holding box.
Thoughts on Tin Oxide? I don’t think I can really say whether or not Tin Oxide is better than the tumble polish. I think my own decisions on stone readiness and capacity of load in the barrel played a significant part in the failure of the overall polish. Let’s just say …. the jury is still out for now!
Batch 27 | 3lb Tumbler 2 | Gemstone Beach / Holding Box | 17 August – 23 September
4lb Tumbler | Batch 27, 28 & 29 | Gemstone Beach & Holding Box | 5 October – 15 October 2023
Hi Chrissy. I emailed Rotorua Lapidary back in November 2020 when they changed from pre and pro polish to just “tumble polish” and asked what was in it. They said it was the same only finer. The pre and pro polish was tin oxide so the tumble polish should also be tin oxide. Or do you know something I don’t?
That’s really interesting and good to know! My thinking so far is that I would not purchase the more expensive “Tin Oxide” as the cheaper “Polish Mix” does just as good a job if not better than the “Tin Oxide”. I guess I got caught up in the “it’s more expensive so I should expect a better finish” thinking and that was wrong!!