Wednesday, September 16, 2009

Intimate Conversation - Part 3

Remember this?

After the diversion of going to a quarry, I’m back to work on this fountain. Having drilled the mounting and water holes, the next step is to remove the remaining stone between the heads and then refine the shapes. I used an air hammer and chisels to cut away the stone. The picture below is part way through the removal process. Notice that stone has been carved away from the backs of the heads as well as from between them. You can also see how rough the surface is from the chiseling … and what a mess it makes. This is one reason I work outside and not inside the studio.

In this photo all of the bulk stone has been removed and we are ready to start refining the shapes and smoothing with diamond grinding wheels and silicon carbide grinding pads on an electric grinder. Stone sculpture is a process of making finer and finer marks – you start with deep gouges made with chisels, remove then with scrapes made by grinding pads, and finish by removing the scrapes with scratches made with sandpaper or diamond pads. Because the scratches are so fine that your eye doesn’t see them, the surface looks polished, but it really covered with incredibly fine scratches.

Here I’ve started shaping the heads doing the first-pass grinding and you can see how smooth they are compared to the chiseled space below them. But, if you look closely you can see that the heads aren’t really smooth – they have lots of flat spots, ridges, grinder marks, and some chisel marks that are still visible.

In the photo below, I’ve started smoothing the bodies and you can see a grinder with a curved diamond grinding wheel. Notice the big chunk missing from the head on the right? That’s the next challenge – how to make it disappear or fit into the design.

Sunday, September 6, 2009

A Trip to a Quarry, or How I Spent my Summer Vacation

The call came at 10:30 am – The quarry called to tell me that they had finished cutting and tipping over a wall and that blocks were on their way to the processing plant. At 7:30 tomorrow morning they would have slabs cut for me to look at.

By 11:00 am I had packed, loaded the truck and was on the road! Destination: a group of quarries south of Albuquerque, a 6 to 7 hour drive. I love the start of trip, Phoenix up to Flagstaff – deep canyons, the fantastic view of the Verde Valley as you descend from the mesa, the red rocks of Sedona, and pine forests outside of Flag. But the part of the trip that I like the best is seeing the great red cliffs on the Arizona-New Mexico border after the long drive across the open, empty plains of I40.

Red cliffs on the NM - AZ border

Got to my hotel and tired to go to sleep on NM time (NM is an hour earlier than AZ this time of the year) so I would be up and alert in the morning. Know what happens when you try to sleep because you have something important the next day? That right, I tossed and turned, counted sheep and tried every other trick I know, but couldn’t fall asleep until the wee hours.

I had set the alarm, so I did wake up early and got there when they opened. It turned out that a pump had failed during the night, so there were no slabs yet, it would be a few more hours – I could have slept in! Instead, I used to time to drive out the quarry area from the plant, about 20 miles away.

Road to the Quarry

The Scherazade Travertine Quarry near the Onyx Quarry I'm going to

This company operates 5 different quarries in this area and they rotate their crew among the quarries depending on what type of stone they need. I'm going to the Vista Grande Onyx quarry and the day I was there they had already moved to a different location. The trailer above the quarry houses a large generator, air compressor, tools, and spare parts.

The Vista Grande Quarry

In the quarrying process a saw like a very long chain saw mounted on a track is used to cut behind the wall. Then vertical and horizontal holes are drilled in the stone that meet in the back corners of what will be blocks. A wire saw is threaded into the holes from the top and pulled out the front and then it cuts the sides and the bottom. Once the block is free, it is tipped over, away from the wall. A wire saw is a long continuous wire impregnated with diamond segments that cut the stone as the wire is pulled. The wire is driven by a motor and pulley system - it is the machine on the tracks in the lower right of the picture. The big wheel drives the wire.

Once the wall has been tipped, a wire saw is used to cut the huge block into smaller manageable blocks weighing between 10,000 and 40,000 lbs. The ladder is about 12 feet long.

A quarry block in the plant

The same block being cut by a 12 foot diameter saw

In the next post we'll be in the plant working on a commission made from stone taken from the Vista Grande quarry.