Reusable mold material for resin casting

Molding and casting your own found items in resin

After playing around with the Composimold reusable molding material last week for molding chocolate, I was pretty eager to try it for casting resin items.  I decided to make resin Legos and used the same molding techniques as I did when experimenting with the material last week.  I used the meltable molding material to create two new molds for casting resin.  I cast two Lego pieces into two separate cups.  I let them sit overnight before I demolded them from their cups.  (In case you want to see pictures, I used the same techniques as I did in this blog post on expermenting with new resin molding products.)

mixing China Blue Stampendous micro glitter into super clear resin

For this experiment, I mixed 15 cc total of the Resin Obsession super clear resin.  I wanted a ‘girly’ version of Legos, so I mixed in China Blue Stampendous micro glitter.

Not shown:  Before pouring the resin into the mold, I sprayed it with a light coating of the Petrolease non silicone food grade mold release.

pouring epoxy resin and glitter into a Lego shaped mold

I poured resin into the mold cavities.  Note:  This molding material cannot withstand extreme heat.  (Otherwise, it melts!).  It is suitable for casting epoxy resin, but not polyurethane resin.  Because polyurethane resin heats up very quickly, it will produce too much heat for the mold and cause it to melt.

flex mold after pouring in resin to allow bubbles to escape

After pouring in some of the resin, I picked the mold up and flexed it a bit.  I did this to allow resin to shift and allow bubbles to rise.  This would also be important if it was a very intricate design, say flower petals for example.

I covered the molds and allowed them to cure overnight.  Note:  once you use this molding material to create resin castings, do not use it for making food items again. 

demolding a resin Lego from a mold

Once the resin had cured, I demolded it the same way I demold castings from silicone: flex the mold, grab the edge of the casting and pull from the mold.  Everything had seemed the same until this part.  The mold gripped my casting much firmer than silicone does.  In fact, I was worried that the resin had stuck to the mold.

removing a resin lego from a mold

I continued to gently pull at the casting and was relieved to be able to demold it.  I’m also betting using the Petrolease mold release was a big help as well.

resin Lego castings

Overall, I was quite impressed with the finished castings.  After my chocolate ones turned out ‘just okay’, I wasn’t sure what to expect when using the molds to make resin castings.

glitter resin Legos

Here’s how they compare to the originals.  The detail is the same!

resin cast Lego

I was even pleasantly surprised to see that the word LEGO came through onto the resin castings.

So what are my overall impressions with this molding material?

1.  I think if I only need to cast a non complicated item once or twice, this material would be ideal.  Being able to remelt it means I can continue to use it for new projects.

2.  If I want a food safe mold, I think this will do the trick.  The only problem is that it’s not heat safe.  If I needed a food safe, heat safe mold, I would use the Alumilite Amazing mold putty to create a mold.

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3.  If I were going to create an intricate mold, two part mold, or a mold I wanted to make multiple castings from, I would make a silicone casting.  I think it would hold up to demolding over time better than this material.

What other questions do you have?


Unpublished Blog Posts of Resin Obsession, LLC © 2015 Resin Obsession, LLC



@Rijacki, yes, I will be carrying the yellow brand. I hope to have it on here in a couple of weeks.


Hello Katherine,

Could you please email me at
I’m very interested in the gold looking round material that your slicing through on the bottom picture.
Could you tell me what you are using?


I’ve been following your posts on this new material with great interest. Thank you for trying out the material for us.

I wonder how well it would do with epoxy clay, if the results would be similar to the chocolate or would it get some of the details.

Are you going to be carrying either brand in your shop?


@Jeanne, for the Resin Obsession super clear resin, yes you can use a scale. If you are using a different resin, then I would suggest contacting the manufacturer directly for advice.


can you use a scale to measure the resin. i cant find the small measure cups. and i use a 2to1 resin.


Good morning!! I need to thank you so much because of your blog I’ve found myself absolutely obsessed also with resin and new things to try in resin last night I dripped in pebeo fantasy moon and prism into a 1/2 sphear of wet epoxy resin the results this am appear to be nothing short of amazing however of course it’s way to “wet ” to demold yet but I just wanted to say thank you again for awakening the creater that was lost or board 😊


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