Looking for some molding suggestions and other considerations

Hello all,

I'm getting close to wrapping up a piece that I want to cast in resin and I'm looking for some insight on molding.

This piece has a lot of fine detail and nooks and crannies and I'm not certain on how to approach the casting process. This is my biomechanical homage to HR Giger - the head, tail, and two smaller heads all detach. Some views for reference are below the text.

My initial thought was to do a brush on mold for the body with Rebound 25 and a support shell using free-form air. My thought was due to the small details and nooks, brushing in the silicone would be best so details were not missed (print layer), and bubbles were avoided, as well as saving a ton of silicone.

The head - was thinking a box mold, or potentially a two piece mold. The two piece mold may be overkill - I'm not certain - but I also wanted to have some practice at doing one. I thought I might be able to run the seam line along the base of the jaw and up along the midline raised rail. The two smaller heads and tail would be box molds.

I have a vacuum chamber and a pressure pot. I was thinking the pressure pot would be perfect for curing the resin in the mold due to all of the detail and potential for bubbles, but I've read you should have your silicone mold made under pressure as well to avoid micro bubbles/impressions on your piece when you get to curing the resin in the pressure pot. If I do a brush on mold, this step doesn't seem possible.

I see this piece as having a hundred different ways to capture bubbles, and have never seen anyone run vents on a brush on mold, so maybe box mold would be best.

My questions:
  • Would I be better off doing the body in a box mold, allowing for as many vents as needed, as well as putting the silicone under pressure when making the mold?
  • When putting a sculpt under pressure while making the silicone mold: do I run the risk of the sculpture collapsing under the pressure (this is sculpted in Monster clay medium)? I haven't seen anyone remark on this, and cannot find anything about it.
  • Would a 2 part mold be a better approach for the body, and just box molds for all of the heads and tail?
  • the nooks, crannies, etc. - are they going to post significant problems? I thought the brush mold approach might overcome this due to being able to apply thick silicone to any undercuts. I'm hoping to capture the fine details, and after a suggestion, have patched in some of it. But not a whole lot.
Thank you in advance for any insight you may be able to provide!








Comments

  • Darrell GreenDarrell Green ✭✭✭
    @Chris Ellerby this one looks next level processes. Any chance of getting a few opinions on this? I am thinking brushing in some of the deeper pockets with a primer coat of silicone to start a first layer in direct contact before introducing any bubbles and possibly using some vibration during the next stages but because the negative locks were so well planned with the removable pieces, I am kinda super into seeing how this one would be stepped in stages. Almost a class in itself for complex or multi step molding.

    Any advice on release prepping?
Sign In or Register to comment.