Need some help with modeling chocolate. Made a few batches yesterday to experiment. 1st recipe i used 2 cups of chocolate white melts and 1/2 cup of Karo light corn syrup. Melted my chocolate and warmed syrup. Stirred about 18 to 20 times to incorporate. Wrapped it in saran wrap and flattened down. 

Other i did merkens milk chocolate same recipe.

Later i measured out exactly 2lbs of white chocolate melts but only used 1/4 cup surup. 

Today all 3 are rock hard, you cant kneed at all just breaks. I took recipe 1 and microwaved  chocolate for a few secs and was able to kneed. It did seem okay, i kneeded an wrapped up again..

Is this normal? By touch the milk chocolate seems a tad softer but not much. Any suggestions of tips as to is that normal or what i did wrong?  Thanks in advance.

I use modeling chocolate for covering cakes and a 50/50 mix of modeling chocolate/ fondant for any flowers or figures.

Every recipe I have seen calls for too much corn syrup. I use 1 1/2 pounds (24 ounces) of candy melts, chips, whatever, to 1/2 cup of corn syrup. Melt your chocolate and stir in the corn syrup. Mix well and turn out onto waxed paper. As soon as it's cool enough to handle, knead the excess oil out of it. It will start out grainy and be falling into little pieces, but it will smooth out nicely once you have the oil out of it.

At this point, treat it like fondant. Don't refrigerate it. Let it rest overnight. Yes, it will be rock hard in the morning, but  a few seconds in the microwave will fix that.

This is what works for me. Good luck.