Stage 2 (220 SiC) in Lot-O (trouble)

[jimg]

I now have a few (mostly) successful tumbles in my new Lot-O. So, far, I’m a big fan!

But I am experiencing a repeatable problem during stage 2 in the vibe after doing stage 1 in a rotary. I use 2 tbsp of 220 SiC grit in the Lot-O for stage 2. It runs fine for around 24 hours, although adding a few squirts of water is usually needed every few hours. 

After the first 24 hours or so, the rock movement starts to really slow down. By 48 hours the movement has almost stopped. Adding water, or a little Dawn, doesn’t help. 

When I empty the barrel, I see the reason the motion has stopped: a big mass of small rocks, ceramic media, grit, and mud clumped at the bottom of the barrel! 

This has happened all but one time when doing stage 2 in the vibe. 

The printed instructions that came with the Lot-O say to do stage 2 for 24 hours using 1 tbsp of 220. Then empty, rinse, and repeat the same thing for a second 24 hours. So same overall time and grit load, but broken into 2 steps. 

Stages 3 and 4 go just fine with nothing similar happening. 

Who else has this problem with stage 2?  What did you do about it?

[python]

I'm not 100% sure as I'm still a newbie, especially when it comes to vibratory tumbling; but from my understanding, 2 tbsp is too much grit for a vibe tumbler. I think most people use teaspoons for vibes.
I think 1/2 to 1 tsp is what is normally used in a vibe.

[jimg]

Aug 23, 2024 22:06:43 GMT -5 python said:

I'm not 100% sure as I'm still a newbie, especially when it comes to vibratory tumbling; but from my understanding, 2 tbsp is too much grit for a vibe tumbler. I think most people use teaspoons for vibes.
I think 1/2 to 1 tsp is what is normally used in a vibe.

Yes, my grit quantities are very small, fractions of tsp’s, for prepolish and polish stages. But almost all the recipes I’ve seen here and on YouTube for the Lot-O suggest 2 tbsp of 120/220 or 220 grit for the first vibe stage. For me, that isn’t working on a consistent basis. 

[chris1956]

I have always used 2 tablespoons of 220 grit in my Lot-O.  I have in the past had some similar issues at 220.   I think it is REALLY easy to  put too much water in and slow it to a crawl.  Try not to put much water in until you get a slurry developed.  Athough I haven't tried this, you might try adding some borax to get the slurry at the start.  Don't know but might be worth trying. 

I think part of my problem was that I wore a depression around the barrel (long story) and my barrel was sitting low in the frame.  I tried tape to build it up but that is messy.  Now I just take a couple of paper towels, fold them up, and put them between the barrel and the front of the frame (away from the motor).   This seems to work well to keep the barrel up.  The other thing you can do for this is cut a small piece of pvc pipe, but it under the barrel under the knoby and hold the barrel up that way.  

Couple things to try anyway.  

Chris

[jimg]

Just completed 24 hours with 1 tbsp of 220, and no caking! Rock movement was good throughout the run.

Rinsed, and started stage 2b, i.e. another 24 hours with 1 tbsp 220.

[jimg]

I know this is a small (1) sample size, but my experiment with splitting the 220 roughing stage into two sub stages worked well.

By the end of 24 hours with 1 tbsp of 220 SiC the movement of the rocks had noticeably slowed, but was still acceptable. I added only the tiniest amount of water during the 24 hours.

Same with the second run of 1 tbsp / 24 hours.

Now running a 72 hour stage of 1/2 tsp 500 AO with 1/4 tsp psyllium and a drop of Dawn.

[jimg]

My rocks could probably have come out of the Lot-O after 72 hours with the 500 AO. They were very shiny after a quick borax burnish.

But I went ahead and ran 48 hours with 1/4 tsp of 61 Rapid, 1/4 tsp psyllium, and a drop of Dawn. Followed by borax burnish.

Excellent results, so I think splitting the 220 SiC stages will be my norm going forward.

I’ve noticed the 61 Rapid polish is fond of hiding in vugs and crevices. My next task will be to see if the 2 micron AO polish I got from Kingsley North for my rotaries has the same tendency, and if it gives an acceptable polish in the Lot-O.