First timer here. I made modeling choc to cover/smooth some numbers I carved out of RKT. I used 7 oz milk choc and 3 T light corn syrup. Left in fridge for 4 hours, then on counter overnight. I kneaded it to a workable consistency this morning and it worked great over the RKT, but is it supposed to be glistening with grease at room temp? I planned to cover it in fondant, but what effect will the oil have on my MMF?
My experience has been that it hardens up again when left alone. There shouldn't be a problem covering with MMF. Just give it a few hours to dry.
Next time don't stir it too much, that helps. You don't need to refrigerate it, just wrap it and leave it on the counter.
You also can "blot" the oily stuff off with a paper towel.
Mix the chocolate and corn syrup until it just comes together. No more than that. I found it works best that way.