Looking for molding suggestions and tips

[Shapeshifter]

I'd probably do a matrix mold for the body and a box mold for the head and tail.
With any mold, you want to degass the silicone. I wouldn't preasure pot the mold when you are making it. Casting resin out of that mold, sure. Also, if you make any box molds you can degass the silicone, pour it into the box mold and degass the entire mold, if your chamber is big enough. That will get rid of most, if not all of your voids.

Thank you for your feedback! A quick question, as this is something I haven't been able to get a definitive answer on: if you pour the degassed silicone into a box mold, and then de-gas the entire mold, do you run the risk of the sculpture collapsing or having some other upset while degassing?

 

[swgeek]

Personally, I've never had an issue degassing the entire mold, but if your sculpt is hollow you might want to skip the second degassing. Also, I don't degass it long, just long enough to pull the bubbles off the surface and out of the undercuts. As soon as you start seeing bubbles on the surface I would turn off the vacuum pump and let it sit for a minute. Then you can let the air back in the chamber.
You can also run a test mold, I've done that in the past.

 

[greenmachines]

Personally, I've never had an issue degassing the entire mold, but if your sculpt is hollow you might want to skip the second degassing. Also, I don't degass it long, just long enough to pull the bubbles off the surface and out of the undercuts. As soon as you start seeing bubbles on the surface I would turn off the vacuum pump and let it sit for a minute. Then you can let the air back in the chamber.
You can also run a test mold, I've done that in the past.

I loved the caution on hollow molds and voids. I have had several classes where the internal structure was foam or wadded tinfoil/paper with a thin layer of molding material on the outside. This would do some strange things in a vacuum housing.

 

[Shapeshifter]

Personally, I've never had an issue degassing the entire mold, but if your sculpt is hollow you might want to skip the second degassing. Also, I don't degass it long, just long enough to pull the bubbles off the surface and out of the undercuts. As soon as you start seeing bubbles on the surface I would turn off the vacuum pump and let it sit for a minute. Then you can let the air back in the chamber.
You can also run a test mold, I've done that in the past.

Personally, I've never had an issue degassing the entire mold, but if your sculpt is hollow you might want to skip the second degassing. Also, I don't degass it long, just long enough to pull the bubbles off the surface and out of the undercuts. As soon as you start seeing bubbles on the surface I would turn off the vacuum pump and let it sit for a minute. Then you can let the air back in the chamber.
You can also run a test mold, I've done that in the past.

Thank you for the insight, it is appreciated!

 

[Shapeshifter]

Hello everyone,

It's been a bit but I wanted to follow up with how the molding and casting process went down for the biomechanical if anyone was interested.

What I ended up doing: Glove mold for the body, box molds for the tail and two smaller heads, and a two-part mold for the main head.

What I used: Mold-Star 30 for silicone, Smooth-cast 305 for resin, and Free-Form Air for the glove mold shell.

This was a lot of work. More than I really understood. But, it was a great learning experience. And I learned a lot. There were mistakes. Very noobish mistakes. I expected things to happen, but there was the unexpected as well. You can watch videos and take notes but you never really know until you are in there, doing it, and that's where the real learning begins.

Box molds could be nicer. They're definitely not sized the greatest and my cuts for extraction were crap, but they work. Glove mold had a number of issues, but it works. Best mold was the two piece mold. Works great with minimal clean up. That was my favorite one to make.

Ultimately it was a success. I am able to reproduce the damn thing and it feels great! Now, how long the mold is going to last...

One thing I tried this weekend was to run a hollow cast with foam. Almost worked, except the resin didn't capture all of the details and it was pock marked. I'm going to go solid cast with some URE-Fil for the reproductions. Presently have one master, one failure, and one fully produced and ready for paint.

I wrote about it in-depth here. This has notes on what I did, what went wrong, and what I will do differently the next time I make a glove mold.
Glove Mold Notes

I also did a speed video. If you're interested in that kind of thing. I'd turn your volume off when watching as I didn't realize a few minutes in there is the sped up sound of whatever music I was listening to:

Here are some pictures:

• Beginning the print layer
• The clay shroud and shims
• Shell complete and prepping to pour the glove
• Glove in shell (cracked the shell but was able to fix with some super glue)
• Body separated from the glove
• Tail and smaller head box molds
• Main head mold
• First two body pulls. The middle one had some issues.
• First complete pull

That's the gist of it. Thanks for letting me share!

 

[greenmachines]

Hello everyone,

It's been a bit but I wanted to follow up with how the molding and casting process went down for the biomechanical if anyone was interested.

What I ended up doing: Glove mold for the body, box molds for the tail and two smaller heads, and a two-part mold for the main head.

What I used: Mold-Star 30 for silicone, Smooth-cast 305 for resin, and Free-Form Air for the glove mold shell.

This was a lot of work. More than I really understood. But, it was a great learning experience. And I learned a lot. There were mistakes. Very noobish mistakes. I expected things to happen, but there was the unexpected as well. You can watch videos and take notes but you never really know until you are in there, doing it, and that's where the real learning begins.

Box molds could be nicer. They're definitely not sized the greatest and my cuts for extraction were crap, but they work. Glove mold had a number of issues, but it works. Best mold was the two piece mold. Works great with minimal clean up. That was my favorite one to make.

Ultimately it was a success. I am able to reproduce the damn thing and it feels great! Now, how long the mold is going to last...

One thing I tried this weekend was to run a hollow cast with foam. Almost worked, except the resin didn't capture all of the details and it was pock marked. I'm going to go solid cast with some URE-Fil for the reproductions. Presently have one master, one failure, and one fully produced and ready for paint.

I wrote about it in-depth here. This has notes on what I did, what went wrong, and what I will do differently the next time I make a glove mold.
Glove Mold Notes

I also did a speed video. If you're interested in that kind of thing. I'd turn your volume off when watching as I didn't realize a few minutes in there is the sped up sound of whatever music I was listening to:

https://youtu.be/awsf7g-eOC8?si=7avRJKWSwhEMC4C0

Here are some pictures:

• Beginning the print layer
• The clay shroud and shims
• Shell complete and prepping to pour the glove
• Glove in shell (cracked the shell but was able to fix with some super glue)
• Body separated from the glove
• Tail and smaller head box molds
• Main head mold
• First two body pulls. The middle one had some issues.
• First complete pull

That's the gist of it. Thanks for letting me share!

This was truly impressive. I believe that is the toughest mold I have seen so far. There are larger ones and ones with sets of characters but for the creation of one that is so complex in the way of undercuts and modules, the result was stunning. I am quite used to people saying they had to restart amd just dump detail in order to get an easy release mold. Way to stick to it. You surpassed all of my previous moulds and casts in one go. I am literally starting a belt buckle right now and am very happy to say, no undercuts because I 3d scanning it when done. Maybe one silicone mold to keep for lost wax brass if I really get into it. Congrats and thanks for the pics!! I know there is a video because I remember thinking I would watch it after you posted it here. You going to make me walk across the street to watch it on SWSCA?

 

[animator]

Fantastic work! I don't think I could have pulled that off! Well done, sir!

 

[Shapeshifter]

This was truly impressive. I believe that is the toughest mold I have seen so far. There are larger ones and ones with sets of characters but for the creation of one that is so complex in the way of undercuts and modules, the result was stunning. I am quite used to people saying they had to restart amd just dump detail in order to get an easy release mold. Way to stick to it. You surpassed all of my previous moulds and casts in one go. I am literally starting a belt buckle right now and am very happy to say, no undercuts because I 3d scanning it when done. Maybe one silicone mold to keep for lost wax brass if I really get into it. Congrats and thanks for the pics!! I know there is a video because I remember thinking I would watch it after you posted it here. You going to make me walk across the street to watch it on SWSCA?

Wow, thanks so much! I also fixed that link - not used to the forum controls just yet.

 

[Shapeshifter]

Fantastic work! I don't think I could have pulled that off! Well done, sir!

Thank you animator!