D

[lavalishus]

d

 

[zorg]

do you mean a cast or a mold? a mold is the thing you take casts out of.

is the foam flexible?

how many copies do you want?

platinum silicone is usually very thin so the first layer probably won't be very thick.

 

[lavalishus]

Thank you! It’s a mold yes I made a mold of a mask bust I had, I want to make it into silicone but dont want to waist to much silicone.. don’t have the foam yet that’s why I’m wondering.. and one copy would be fine thank you!!

 

[JPH]

You are soooo much better off using a decent amt of silicone for the mold, then put some little pieces of foam to make the outside of the mold lumpy. Next, use a rigid outer shell to hold the silicone.

I would NOT skimp on the silicone. If it tears, you will spend more time trying to fix it and probably have to start over.

Get a good 1/4 inch of silicone. Brush on the first layer, try to avoid bubbles.

 

[lavalishus]

Thank you!! I do mean however to cast it.. meaning if I can cast a layer of silicone and then the rest with foam? So the final head will have the face with silicone but the rest of the head and the back as foam....?

 

[JPH]

The foam will not want to meld with the silicone, so the silicone being lumpy on the non-face side --on the side that contacts the foam-- should be lumpy as registration points. That way you can slip off the face part and add it again with a perfect fit.

 

[lavalishus]

Thanks so much

 

[lavalishus]

Any idea what foam would work for this btw?

 

[JPH]

Id pack with FreForm Air. Not foam, but a sculptable marshmallow-like substance until it hardens. Also very light.

 

[JPH]

PS - don't " pack" with Freeform air. Press a thin layer to create a sturdy outer shell to the volume where the foam would fill.

 

[lavalishus]

Great thank you!

 

[kruleworld]

i've not seen with foam, but i have seen rigid molds made with a layer of silicone (for detail) and then covered with fibreglass to keep it's shape.

do you mean a cast or a mold?

 

[lavalishus]

thanks! For the casting?

 

[swgeek]

You should be able to do a layer of silicone and then pour in a rigid foam. Just make sure everything has set before you pull it out of the mold.
As mentioned before I would make sure the silicone is at least a 1/4" thick.

 

[lavalishus]

Thank you! I’m doing it all now the only problem I’m coming across is the silicone not being thick enough? Should I wait for a layer to cure before adding another? The liquid drops from the sides of the head forming a puddle of silicone in the bottom of the cast