Visit to a bronze foundry - sand casting

Following on from Tuesday's blog, I wanted to show you a little of the sand casting work we saw on our recent visit to the  Pangolin Foundry.

Large outdoor sculptures tend to be cast using sand for molds.  This involves huge three dimensional jigsaw puzzles of sand blocks formed around an original sculpture. The sand is mixed with sodium silicate. Tiny holes are made it the sand blocks and then carbon dioxide is put in the holes and the silicate reacts with the gas to create a glass type binding on the sand, making it a hard block.

The precision used in making the sand blocks was astounding with such straight surfaces and defined angles.

When all the blocks are made and hardened around the original, they are taken apart, the original removed and then reassembled. A core is then made, allowing a space of approx 10mm which represents the final thickness of the bronze.  The core is also made of the sand/silicate material, on a steel support frame.

The molten metal is then poured into the molds after the completed core and surrounding blocks have been encased in steel boxing.

Similar finishing work to that done on the lost wax cast sculptures is then done and patina is added.

Here are some of the other finished sculptures we saw:

Bronze covered in auto paint

Bronze Fish and Chips!

You can see this in a previous photo, upside down, before the bronze was poured in

It was an amazing tour and fascinating to see the processes involved in creating these enormous sculptures - some of them up to 100 feet tall!!

If you ever get a chance to tour one of the big foundry - go for it! You'll be fascinated too!

5/52 - Bird a week - A bird in the hand

Time for another "bird a week" (- my little challenge group where we make a different bird each week using whatever media we like).

This week, my birdie is based on a phrase that means a lot to me - "A bird in the hand." If you read my blog regularly, you'll see that each Saturday I write a "bird in the hand" blog post which lists the things I'm grateful for that week, as I see the saying "a bird in the hand is worth two in the bush"  is all about being grateful for what we have.

This is my first wax sculpture. The hand is life size.  The two pieces are going off to be cast in bronze.  My first bronze sculpture! I'm quite excited by the prospect of it.

The photos are from different stages along the way and not the final pieces.  We'll wait until they are in bronze to see how my final refining and details came along.

The pieces will remain separate - not connected - so that you can pick them up and change the position etc. 

I loved working with the wax.  I really like how the hot tools just glide into it...how you can add and take away easily - and how you can add so many details. I learned under Rita Torlen, here in San Miguel. She is the same teacher that I had for my "girl with the bird in her hair" clay sculpture.  I've so enjoyed my classes with her.  They all called me "the bird lady" in class!

Doing the bird was fascinating. With most of my jewelry, I like simple designs, not much fuss or texture, but with this bird, I thought I'd try something different and put all the little feather patterns in. It was such fun to do.  And doing something life size was a welcome relief after all the tiny jewelry sculpting I do!

I know I will be doing more bronze sculptures when I get home, using the wax for models.  Here in Mexico, the price for having it cast in bronze is very reasonable - can't say the same for the US ...but maybe I'll just ship them back down here.

 

There are a good group of us doing the "bird a week" challenge so I hope you'll take the chance to look at some of the others by following the links below.  Hopefully those in the challenge will add their blog post link or flickr photo link. If you would like to join us in the challenge, you are most welcome.  Click on the flickr group link for more info.