Help! Epic Alumilite fail

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ramaroodle

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Feb 15, 2018
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My first attempt at casting ended up looking like an elementary school volcano experiment. I've read all of the posts I could find about foaming problems etc. I mixed the Alumilite clear by weight added some alumilite blue dye, stirred well and poured into my HDPE molds. Almost immediately it started to produce little tiny bubbles then just kinda overflowed the mold before I could get it into the pot. I stuck them into the pot anyway overnight and it came out looking a lot like it looked going in, just kinda' frozen in time like a lava flow. One blank had a piece of stabilized burl and the other was an empty blank. They both did the same thing. I did wash the molds before their first use but thought I did a pretty good job blowing them out with compressed air. I did use dados when making the dividers.

Is it possible that this was all caused because some water may have been hiding in the cracks of the dados?
 
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Terredax

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Nov 1, 2015
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It's most likely moisture. ANY moisture can cause the foaming.
Keep in mind, that polyurethane resins are very similar to polyurethane adhesives, with slight differences in formulation for the intended purpose, but mostly similar.

When using a polyurethane adhesive (think Gorilla glue), the adhesive is applied to one surface, and the opposing surface is dampened with water. This combination causes the adhesive to foam and expand, so the same reaction will happen when moisture is introduced to polyurethane resin. The foaming and expansion.
 

ramaroodle

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Feb 15, 2018
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Location
Seattle
Live and learn!

So, how high a temp can my HDPE mold take without melting if I stick it in the oven to dry it out?
 
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