Designed specifically for your brand of tumbler, and for your exact model. Brands such as Smithsonian, National Geographic, Thumler, Harbor Freight, and Lortone. Each product packet contents follow the manufacturers specifications.
The Right Amount of Grit and Polish
These grit kits are carefully assembled to provide the correct amount of grit, by weight and by formulation. This mean that because each tumbler brand varies specifically in its requirements for the type of abrasive media compound to be used, you must utilize the correct elements for that tumbler.
While there is not a great deal of variance in guidelines for which chemical abrasive to use there are some differences.
Amount of Abrasive Compound
One of the variations between tumbler brands is the amount of material to use in your tumbler at each phase of the rock tumbling process. Like anything, the excess amount of abrasive is not always positive. Think of the ditch digging metaphor. Two people can dig a a ditch in an hour. But using twenty people does not make it 6 minutes.
The reason for this is that you are building what is called a slurry. If you use too much grit it gets all caked up and does not circulate around the barrel. The kits are measured to the manufacturers specifications