Are Two Barrel Tumblers better/Why?

[Alley]

Hello,
  Can someone guide me on Tumblers,why are two barrels better then one big one?
Bye Alley

[Aussie Sapphire]

There are a few things to consider when choosing a tumbler.

1.  Intended Usage
If you're polishing metal (such as jewellery, brass, gun cartridges, etc), you can usually work with one barrel and most people find the smaller size adequate unless they are doing large amounts.  Need to keep metals separate but this will normally be the case anyway.

If you're polishing rocks, you'll be going through a staged set of grinding/polishing processes and it is in this case that most people find the double barrel type more convenient.

This way you can have one lot grinding in one barrel while another lot is polishing in the other - speeds the process up.  Also, you need to be very careful with cleaning out the barrels when moving to a finer grit to avoid scratching the rocks. For this reason, some people keep the grinding and polishing barrels separate so there is no chance of a stray coarse grit particle contaminating your polish stage.

2.  Size of Barrel
There is an optimum amount of material which should be placed in the barrel - for rock tumbling it will generally be around 2/3 full.  So the size of tumbler chosen will depend on how much material you will generally be working with at any one time.

Most people start with a standard 3 pound barrel type tumbler - for the lortone, this is about a 10cm diameter/10cm depth cylinder.  If your rocks are larger than can fit in this or the size of load is larger, then you'll need to move to a larger barrel type.

hope this helps,
Andrew - Aussie Sapphire

[calxoddity]

Alley,
  I've been using the 2-barrel Lortone tumbler for around 5 months, and the two barrels gives a lot of flexibility.  I've actually got 3 barrels, set up as follows:

Rough - this barrel is usually used for 80 grit and sometimes the 220

Fine - mainly for 600 grit unless I've got a heap of rough stuff to tumble, in which case I use it for 80 or 220 grit but wash it out VERY carefully afterwards

Polish - this barrel is used for polishing ONLY, with 1200 aluminium oxide and the final polish of 0.5 micron aluminium oxide (veeery shiny!!)

The cool thing with the 2-barrel tumbler is that you can be polishing one batch whilst grinding another.  It also allows you to rough tumble 2 batches at once and be picky on the stones you take forward to the next stage, yet still manage to fill your polish barrel at the end.  I got tripped up big time initially when tumbling rough quartz - the wastage was so great that by the time I got to the polish stage there was only half a barrel of material.

Regards,
Shane

[Aussie Sapphire]

welcome to the forum Shane - it is so brand new we havent even "taken the wrappings off" properly yet - gotta tweak the logos and such before we go into full publicity mode.

The wastage issue is a good point - do you find this is a bigger issue for some gems compared to others?

Plastic pellets are an easy way to top up a load but I know some people have lots of half-polished rocks on hand to throw in for this purpose - maybe they're not good enough to polish through and look great but they're fine to use as filler.

cheers
Andrew

[calxoddity]

Andrew,
   Yeah, just got back from NZ this morning and thought I'd have a look... this will be a good replacement/enhancement of the MSN groups forum.

With wastage, this is what I've found so far:
- Quartz jellybeans don't waste much unless you go crazy with 80 grit.  I start them in 220.
- Rough fractured quartz, not the cryptocrystalline varieties, does waste quite a bit.  It's not as tough as agate pet wood, chalcedony etc and as the edge smooth off it occupies much less volume.
- pet wood and agate is pretty tough and doesn't seem to waste much, unless you have really jagged pieces.  Waterworn pieces maintain volume very well.

I discover stones that are irredeemably fractured from time to time and remove them before they split and wreck the good stones.  I have old takeaway containers marked 80, 220, 600, 1200 that I keep stones in that have gone thru that grit level, and use these to top up a barrel if needed.  I make sure I mix like with like, of course - soft stones with hard makes Bad Things happen... 

I use plastic pellets in the polish stages partly as filler and partly as cushioning.

Regards,
Shane