Laser Brain
Sr Member
Very nice. Man, I love carving PU foam, I don't get as much opportunity to do it as I'd like, unfortunately. You did a great job.
ITS PURE BEAUTY! I'm truly inspired by your work man!!!!!!
@ SeanB13: I use just straight up hardware store Plaster of Paris for waste molds. Something like Hydrocal or Hydrostone would be more difficult to remove. Rigid moldmaking is usually a rough process for models unless you're unbelivably thorough with your design of parting lines and undercuts. I've molded plastic skulls in plaster and it took at least 10 interlocking parts. Still, for clay it's almost guaranteed that you'll lose the original in the process.. rubber moldmaking is far less invasive.
To prep the pieces for reproduction, I had a choice to make between hard-coating the foam forms, or molding the parts and casting them in a more durable material. If I were only making a single backpack, and it didn't need to be hollow for functionality, or if the goal was to be a silicone mold, I could have just hard coated the foam. The hardening process could lose some detail that was carved, but it could be sanded and re-defined with more surfacing work. I wasn't totally confident how the hard coated foam would stand up to vacuum forming, so I decided to mold and recast the backpack parts in a more durable material.
Since I only needed a single cast of each part, I opted to make simple plaster waste molds.