Worn out rubber inner barrel lid

[Fullerton]

I am using a Lortone 3A tumbler and the inner rubber lining of the lid has worn a hole out of the centre after only a couple of weeks of tumbling.  I had been tumbling mostly garnet and amethyst in separate batches.

My last one did the same but it had lasted 18 months.  The wearing occurs around the central point.  Just wondering if the rapid wear can be attributed to too much or too little rough ... or why would the rubber lid wear so rapidly?  I didn't think my load levels had really changed... usually 2/3 to 3/4 full. 

Cheers,
Fullerton   

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[Andrew]

Hi Fullerton,

This is interesting - something certainly seems to be going wrong to be causing this excessive wear.

The Lortone 3A and 33B which use the same Barrels/Lid Gaskets and are our biggest sellers with many hundreds sold each year. 

Even with the hundreds of machines we sell and service with consumables, we sell very, very few Gasket Lids (or even full barrels as replacements) so I think something strange is going on

Trouble shooting:

1- Your 2/3rd full is the normal Level so that's fine.
2- What Grit are you using as your first stage grind?
3- How much Grit are you adding to a Barrel load?
4- How much water per Barrel load are you adding?
5- Are the rocks particularly jagged or rough in the first stage?
   
If anyone has any ideas on this, please add here. 

I will do a bit more research on this issue and see if we can come up with a solution for you.

cheers
Andrew

[Fullerton]

I only use the tumbler for cleaning up rough prior to cutting so they all at the first stage ... I wouldn't describe them as overly jagged though. 

Rough is tumbled for between one and three days depending how 'clean' I want it.  I use mainly 46 or 220 grit but only change the grit if needed.  So for the two week period of wear I might have had an original grit added and then one change of grit.  I add about 2 tablespoons of grit and the water is either at or just below rough level.   

Fullerton 

[Andrew]

The #46 may be the problem (or part of it).

Aussie Sapphire and Lortone Recommend #80 Grit as silicon carbide for the First Stage.  We sell #46 but only where very Aggressive Grinding is needed and we recommend keeping a closer eye on when using this grade.  #46 is also used for Non Slip applications so basically use with more care than usual in a tumbler.

If you use a media that is that aggressive, it will work on the Stones and the Barrel (whatever Brand) in a similar way and wear both faster.

For the Benefit of others on the forum our usual advice is:
First stage #80
Second Stage #220
Third Stage #600 (All Silicon Carbide)
Final Stage Polish Cerium Oxide, Tin Oxide or Aluminium Oxide as appropriate
You may choose to optionally add a pre-polish step between the #600 and polish steps.

In cases such as with Fullerton where you are just cleaning up stones in preparation for another job rather than taking them right through the tumbler, drop later steps as needed.

The amount of grit and water sounds about right.  You could try adding just a small amount of pure soap (lux flakes or the like) or something similar (Americans usually recommend Dawn dishwashing liquid but it needs to be non-foaming and without additives).  This has been suggested by some to make the rocks more "slick" - usually not necessary but in this case it might be worth a try to see if it helps.

cheers
Andrew

[Fullerton]

Thanks Andrew for the advice re: grit and pure soap. 

I bought the #46 grit at a gem market stall where I asked for a grit which would help clean up rough in a tumbler ... perhaps more aggressive (course) than I needed!!!

I'll be puting an order in to Aussie Sapphire in the near future to replace the lid and will start using just the 220 grit for my 'rough cleaning' needs. 

Cheers,
Fullerton

   

[Aussie Sapphire]

We do sell a bit of #46 for tumbling but you do need to be careful with it - if your rocks are not particularly jagged and/or hard, I would not be recommending it for you.

We sell it for other jobs as well.  One of the more unusual ones was to a competition target pistol shooter - ie. a guy who was trying out for the commonwealth team (not sure if he made it though).  He used it to put on the grip of his gun to make it less slippery.

We'll be getting some #20 silicon carbide in our next order for similar types of jobs (non-slip applications) - I would not be using this in a tumbler at all.

cheers
Leah

[Andrew]

 Fullerton,
  You could Glue a extra piece of Rubber onto that old Lid Gasket with Contact Adhesive our Silastic,just keep the Gasket area clear where the Lid seals into the Barrel.
Andrew

[Fullerton]

Thanks, I'll try that ...   

[Fullerton]

Ok, I've glued a patch of car tube to the rubber lining ... and it's lasted 24 hours.  Also now using #80 grit as a starter.  So this looks like this'll save me replacing the lid for a while ... 

[mehoose]

Excellent. 

[Blocker]

Found this on a website might be of help re the hole in the inner lining he was refering to a lortone 3B: 

If your tumbler has lids like the one mine uses, there
is a bolt end on the bottom side. Place an adhesive
bandage over the nut end and then put the rubber
membrane back on. This will help prevent the nut
from wearing through the rubber membrane as the
rocks tumble against it.

[Fullerton]

You're right Blocker ... it is the bolt end that wears.  Funnily enough, there's raised metal text on this which worsens the problem.  I have already glued some car tube inside the rubber lid to fix the problem. 

Has since been working fine and doesn't appear to be wearing.  But I might also gently file and polish the bolt end so that it's smoother .... and/or also apply an adhesive bandage as suggested.   

[Blocker]

Well my new lortone 33B has arrived -  considered the issue of that bolt end and what might be best.

Whilst sitting at the computer, noticed a foam ring on the spindle of a set of blank DVDs.  It fitted very nicely over the bolt like a corn plaster does over a corn.  So I'm giving it a try to see how it works. Made a 2nd one out of packing foam that came with the tumbler. Will post results of the experiment.

Fullerton - How's your efforts working out?

[Fullerton]

Yes, tumbler is going well ... still going as I write this.  My rubber tube repair is working nicely. 

I think the raised metal text on the bolt end had some surface rust as well which made the bolt end even more abrasive.


 

[Andrew]

 The build up of rust must be the Demon    As I said before we just dont supply many replacement Barrel Gaskets and sell hundreds of machines each year.
 There is always a reason just need to sort it out
Cheers Andrew