Gedeo colored Resin and Gedeo Molding alginate not getting along.

Let me begin by telling you a little bit about what I?m
trying to make. I?m making a head band, it will be a rounded strip across the
top which dragon-like spikes protruding out of it in two to three rows. Kind of
looks like shark teeth on a strip. 😛

The problem is that?s I don?t know what to use for the mold.
It has to be flexible enough for me to be able to wiggle the original out (which
is currently made out of a hard wax), and I need to be able to pour the alginate
or whatever material the mold will be made out of over the original because
there are fragile parts and odd shapes that a putty wouldn?t be able to fill
properly.

I was advised by DeSeres employees that the Gedeo molding
alginate will be fine to use for the resin and for the time being it was, it captured
the shape nicely, and I was able to preserve the original when I wiggled it
out. However when pouring the Gedeo already colored resin to it kind of pushed
some of the molded alginate apart (but its fine because I secured it together),
and the main problem was that after about 30h of me waiting for it to dry its
still sticky and looks like the green (the resin color) is now marbled with the
white (the molding alginate). The parts that are in the center which had little
contact with the alginate itself are hard, so I know its not the resins
problem.

My question is what can I use to make the mold, that is flexible
and can handle resin being poured in it. OR what did I do wrong? Maybe I didn?t
let the mold alginate dry enough before I poured the resin in which caused the
fusion? When it dried it seems to shrink or like it morphed, is there a perfect
time where its dry but not yet slightly shriveled?

Please let me know what im doing wrong, or recommend a
better product but please keep it in the supplies I can buy at a general art
store. I don?t have the option to order anything online right now.