Well we’re underway.
Uncle Robot was in full swing by 11:00am today and has already made remarkable progress. He decided to start with splitting some of the large rock floaters into manageable sized blocks, as the large rocks have to be moved to make way for the chook nook. The blocks will be used to build the retaining wall for the chook nook floor, for the base of the water tank pads and for some of the garden beds. It will also give him a level area to work from as it’s very tiring working on a slope all day.
Here’s some shots of the rock splitting process.
The first step is to cut a groove in the stone with an angle grinder. The disc is a diamond wheel, not cheap but the strongest of the cutting blades and essential for cutting sandstone that has a very high quartz content. In the mineral food chain, diamond sits at the very top as the hardest and is why diamond is used for cutting very hard materials like cement and rock.
Full PPE (personal protection equipment) in this case, eye protection and respirator, must be worn during the cutting process which creates a very fine dust. The dust particles contain silica and long-term exposure to this dust can cause silicosis, an occupational lung disease.
Next, metal wedges are hammered into the slot to help prize open the rock. Sydney Sandstone is a sedimentary rock which was laid down in large river systems about 220 millions years ago, during the time of the dinosaurs. When the sediments were deposited, they naturally formed layers which you can still see in the rock today if you look closely. The stone mason aligns his cutting wheel along these natural layers to help with neat edge splitting. Sometimes the wedges do the trick and the rock will gently split open and voila, you have a block.
For more stubborn pieces the stone mason uses a crow bar to help the rock split off. Rock doesn’t always co-operate, so you have to be patient.
This piece on the right is about 1.5 metres long and 60cms wide and was cut and split off using exactly the same method as I mentioned above. The next step is to split this large piece into smaller usuable blocks.
And this is what you end up with…..
….a pile of usable blocks that were made in about 3.5 hours by one man….our Uncle Robot the human rock machine.
These blocks are about 6o x 40cm.