Week 12
Mold Making
The assignment this week was to machine a mold and cast a part from your mold. After vinyl cutting, this is definitely my next favorite process in the lab and I played around with a lot of options.
My Fiance and I are actively planning our wedding and working on all of the various paraphernalia that goes along with that. One of the things we were interested in was making a wax seal on the back of the invitation envelopes, so I figured this would be a great week to play around and see if we can make that possible!
First, I modelled a simple little mold in Fusion 360. I imported an svg of a pineapple, extruded the outline and then put the solid body on top of a small disc inside of a well to hold the silicone.
I then setup the Roland Modela with a block of machinable wax to make the initial mold. I used a normal 1/8" straight bit for rough cutting, but switched to a 1/64" ball nose for the finish as I had many small features and the 1/8" bit wouldn't be able to mill these details.
The mold looks nice, still has some dust in it but that is easily blown out!
We then poured some Mold Max 60 into the wax mold to create a silicone negative to allow us to pour some cerrotru pewter and make a final product. While Mold Max 60 requires a 24 hour cure, I put the entire mold into an oven at 150 F, which accelerated the curing and I had a completed, solid mold within about 3 hours.
The silicone mold looks great!
Although I've used babbitt and other Tin alloys quite a bit in the past, I decided to experiment with cerrotru as suggested by the lecture. I was really impressed with the cerrotru, it appears to flow a little bit nicer than babbitt (presumably due to the lower melting temperature) and gives a very nice surface finish!
The stamp looks really great too!
Finally, it came time to test out the stamp itself! I poured some molten machinable wax on a folded piece of paper and pressed the stamp in it. To my surprise, it totally worked!
