For the last 9 years, I’ve been going to Brazil at least once a year. It could be more often, but it’s a long, long way from here.
I usually travel with 2 other owners, one from Ohio and one from Minnesota. We plan these trips months in advance.
From the first time to the last time [3 months ago], things have changed considerably.
The use of resins in slabs to both strengthen and fill voids has changed quite a bit over the years. Pre resin, the waste factor on slabs was quite high. Now, with the introduction of 72 hour [cure time] resins, factories are able to penetrate the surfaces quite efficiently. This adds strength and enhances the natural beauty of the stone.
When I first went, the longest cure times were 24 hours. It then graduated to 48 and now to 72. There is a marked difference in the finished look between 24, 48 and 72. The slower cure time makes for a stronger product.
Back in the day, polishing machines were ‘single head’ types. This means one head has to polish the entire slab by itself, gradually increasing grits until a final polish is accomplished.
From there, they invented single head machines that were tied together. 3 wide and 3 deep. A total of 9 heads, but essentially
still nine individual heads processing 9 separate slabs, grit by grit. So, polishing became 9 times more efficient from a time perspective. At the cost of floorspace.
Now, polishing [at the larger factories] is done by multi-head machines. The number of heads can range from 3 -30. Usually, they have at least 18 heads . Small footprint, and can process a slab every 1-2 minutes. The more heads, the faster the result. Obviously, this was a radical improvement.
There is always a ‘bottleneck’ in manufacturing. I don’t care what industry it is. You identify it, you correct it and you think it’s over. It’s not. The bottleneck simply moves. It’s like whack-a-mole.
In Brazil, in the factories, the bottleneck became sawing.
The long time method for cutting stone has been gang saws. Essentially, these things look like 2 old time lumberjacks on either side of a log, pushing and pulling the blade back and forth. This is what gang saws do, but they have multiple blades all running at the same time.
The blades are vertical steel and what really ‘cuts’ the stone is the slurry that they introduce beneath the steel blades.
A ‘soft’ granite [like Santa Cecelia] would take 3 days to cut with a traditional gang saw. A quartzite like Macaubus might take 3 weeks. Along with other factors, this is what makes some stones so much more expensive. They take a ton of time to produce. These things ran 24/7 for 364 days a year.
3 years ago, we took our ‘normal’ tour of the factories in east central Brazil. At the large ones, they were all preparing foundations for the latest innovation in sawing: the Wire Saw. Massive amounts of concrete to handle all the weight of these things.
2 years ago, the first ones were in production. Last year, they were becoming more prevalent.
Wire saws run continuous loops of what look like necklaces , but the necklaces have diamonds embedded as the cutting agents. So, they place a block of granite beneath the saw, and 42 wires, spaced 3cm apart, descend upon the top. With a copious amount of water added for cooling.
That 3 days for Santa Cecelia became 6 hours. That Macaubus went from 21 days to 3.
The sludge from the gang saws is classified as a hazardous waste in Brazil. Disposal methods are clearly defined and expensive.
The sludge from the wire saws is granite slurry and water. The slurry is used in bricks or roads or concrete and the water is recycled.
Another bottleneck ‘solved’.
No, as usual, it simply shifted. With sawing now 7 times faster, they can produce 7 times more material. So, sales now have to increase 7 times or you build 7 times more space than you currently have.
That’s what we found 3 months ago. Warehouses are packed. Prices have eased. Choices have multiplied. Quartzites are a lot more prevalent, which is good because that’s a superior product.
Next time we go, we’ll see where the new bottleneck is.