Make a plaster mold of macrame cushion cover.

[vika]

I read that murphys oil soap was a good release agent.  Can someone tell me how to apply it to the macrame?  Do I spray it or brush it - brushing may allow it to absorb a lot.  Perhaps there is something more suitable.  Any comments would be most appreciated - thank  you.

[JohnnyK]

Hi vika...would you show us a photo of the object you are trying to make a mold of?

[Min]

I think I would use some sort of physical barrier like a very thin piece of wrinkle free plastic wrap.

[vika]

Photo of macrame cushion cover

[Jeff Longtin]

Hello Vika,

It would appear that this is fabric, correct? In that case you need to seal the material before casting. A spray urethane would be best for that. You would probably need to apply several coats. 

Apply the urethane thick enough so you see a glossy reflection. That will tell you the fabric is sealed. 

Murphy's oil soap only works on porous materials like plaster or wood. 

As there appears to be many undercuts you may run into problems with the plaster getting stuck in the crevices. A simple way to seal those holes would be to apply a thin coat of plaster and then wipe the fabric with a sponge BEFORE the plaster sets up. Allow that layer to dry (30 minutes) Then apply a thin coat of Murphy's to the surface.

This will be a difficult thing to mold. Be prepared for a few challenges.

[Roberta12]

What about making a bisque mold of the fabric?  Roll the fabric into clay, dry and bisque, then make a plaster mold?  That would work if you are trying to get the texture of the pillow.    You could even drape the clay over the pillow to get the shape, roll the clay into the pillow and peel it off, retaining not only the texture but you could manipulate the clay to keep the shape of the pillow.  Just an idea.

 

[Jeff Longtin]

I think Roberta has the better suggestion. The depth of the fabric makes it very challenging to plaster. Rather than have that challenge just roll the fabric into a soft clay slab first and see if you like that. 

 

[vika]

7 hours ago, Jeff Longtin said:

Hello Vika,

It would appear that this is fabric, correct? In that case you need to seal the material before casting. A spray urethane would be best for that. You would probably need to apply several coats. 

Apply the urethane thick enough so you see a glossy reflection. That will tell you the fabric is sealed. 

Murphy's oil soap only works on porous materials like plaster or wood. 

As there appears to be many undercuts you may run into problems with the plaster getting stuck in the crevices. A simple way to seal those holes would be to apply a thin coat of plaster and then wipe the fabric with a sponge BEFORE the plaster sets up. Allow that layer to dry (30 minutes) Then apply a thin coat of Murphy's to the surface.

This will be a difficult thing to mold. Be prepared for a few challenges.

 

[vika]

Thank you for the comments - i will try as suggested, a much better way!