This initial step is all about getting ready to tumble rocks. As with any relatively complex hobby, it takes time to set up and ensure you have the correct environment and rock tumbling equipment prepared before you begin to actually polish the stones.
Decide where you are going to locate the rock tumbler. You should consider that it will make a noise as the rocks bash against each other as they rotate in the barrel. Whilst this noise is not particularly loud, it is very persistent, it will be present day and night for weeks at a time with no let up except when you check the progress and move to the next stage. You can attempt to reduce the noise by sound proofing and area around the machine at least 3 feet away from it – square.
Next, ideally you will have a dedicated worktop or table to use just for tumbling. The last thing you want is to have clutter around the machine which could become entangled with the drive belt causing it to jam. This will damage the motor (probably beyond repair) and stop the progress of your batch. Always keep tools and other bits and pieces away from the machine whilst it is working, you won’t be able to see it 99.9% of the time it’s running, so it must be in a safe place where it can run night and day without interference.
Because the barrel is full of rocks and water, and it is rotating, it naturally causes the tumbler to “walk” slowly along whatever it sits on. A slight slope in one direction, or a slippery smooth surface will aid this process and unless you take initial steps to prevent it, you will find it on the floor broken the next time you visit. To get around this, either fix it with screws to the work surface or table, or build a wall about an inch high (in wood) around the base, this will stop it moving as it works over the coming weeks.
Rock tumblers need a constant steady supply of electricity. Whilst all models come fitted with a plug and lead, you may find an extension lead useful so that more options are available to you in terms of where you will site it. When running cables, and this especially includes the flex from the machine to its own plug, make 100% certain that the wire cannot twist or move (through vibrations and movement) anywhere near the barrel as it turns. If a cable is left in contact with a rotating barrel for a length of time, friction will wear through the protective sleeve and expose the copper causing a possible short and in the worse case – fire. Clip the cables down if you think this could be a problem, in particular consider this if your cables run from above and could drape or fall onto the barrel.
As you will be aware, the tumbling machine is basically an item which can be described accurately as “electrical equipment”, for this reason, safety is of paramount importance and thought should be given to the location it will operate in. Always make sure it is sited in a dry cool enviroment, damp and extreme cold or heat will kill the motor over time – if not immediately. If children are around who are not of a responsible age, then it is the owners responsibility to absolutely ensure that the children can not gain access to the tumbler. Treat it with respect and it will give years of enjoyment – treat it unwisely and it could cause harm if in the wrong hands. Very basic but essential care should be applied – as with any other electrical item.
Once the machine is sited in a suitable location, it’s time to address the rocks themselves.
Many rough specimens either purchased or found in the field will be too large for most rock tumblers, additionally, a batch of rocks needs to contain a range of different sized chunks. This is because if they are all large, there will be spaces between them and the grit will not have enough contact over time to cause significant grinding. A good mixture of pieces of various size is essential for a top quality final finish. To achieve this, you need to break up some of the larger pieces with a hammer. To do this, it’s a good idea to wrap the ones to be broken in a towel and hit them hard and sharply on a very solid foundation. The reasoning behind the towel is so that shards of broken rock do not shoot off and hit you in the eye – which they wouldn’t anyway because you will be wearing your safety glasses.
Now that your gear is in place, and your rocks are ready, it’s time to load the barrel and them rolling.