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Weird Thing Happened to Me Today Mold Making

PostPosted: Tue Mar 22, 2016 7:47 am
by CatMorgan
So Showing kids how to do this in drama club. I've made mold boxes using LEGO before --- I used CopyFlex food-grade silicone to make candy molds last summer and it worked great (I made molds to make candy lego and just build the box out of the LEGO too.)

Drama teacher got OOMOO 25 cause it was the cheapest (I suspect this is the problem; I told him to get CopyFlex) to make bottle molds for sugar. Built a box of LEGO around bottle, poured OOMOO and ... it started oozing out of the bottom of the box. Is OOMOO thinner than usual? We saved it by packing it with playdoh I had in my room from knife practice (I teach foods and know how to make molds, which is how I ended up doing this) and it worked but I've never seen liquid silicone leak. Is my gut right that OOMOO is just cheap and thin or did I miss something else?

Thanks!

Re: Weird Thing Happened to Me Today Mold Making

PostPosted: Wed Mar 23, 2016 7:46 am
by mangozac
Oomoo is pretty common so that of itself shouldn't be an issue. And being thin doesn't translate to being cheap - it's just different properties. For marking anything more than a simple mould you want it as thin as possible to help remove bubbles.

How was the Lego box being held down?

Re: Weird Thing Happened to Me Today Mold Making

PostPosted: Wed Mar 23, 2016 10:24 am
by CatMorgan
Just the LEGO on the baseplate. Packing it with Playdoh (homemade so no sulfur, just flour, oil, salt and water) stemmed the tide. I'm looking at pics from last summer and I'm thinking we needed to make the wall more than 1 Lego deep?

Sugar bottles look awesome tho and shatter great!

Thanks!

Re: Weird Thing Happened to Me Today Mold Making

PostPosted: Wed Mar 23, 2016 5:26 pm
by mangozac
Ahh I see. Yeah I usually build my moulds from the two stud wide bricks. I also make a point of pressing down really heavily on the box once it's been made to make sure the bricks are tightly joined ;)