Mold Backcast for 3/4" x 8 3/4" blanks

[rherrell]

I made this for a well known pen company, he called it a "mold backcast" so I'll take his word for it.

The shell is 24ga. galvinized steel.

The rods are W-1 Tool Steel, the same material that my toolrests are made from, polished to 800 grit.

The base is 3/4" Delrin.

I had fun making it, I love doing something different.

Here are some pics, I hope you enjoy!

 

[duncsuss]

Am I right in guessing it's a "master form" that he'll use to make blank molds for vertical casting? I've seen two-part silicone mixtures for sale but hadn't figured out how to get the cylindrical holes - my gut told me that wooden dowels were not going to be easy to remove, polished steel should be much better

 

[rherrell]

Yes, I also thought it was a "master" but he called it a backcast.

The sides stick up 1/2" above the rods, that will become the base when you remove it and turn it upside down. It's filled with silicon rubber.