Cut star comp splitting

[BlueComet24]

I make almost all of my stars by cutting them, and have noticed that with many comps (C6, TT, N1, and others) the edges of my patty of comp split when I roll it out. This isn't a big problem, because I can just squish the edges together and re-roll the patty into the desired thickness, then cut it, but I still have a concern about this other than the inconvenience: The top of my patty of comp cracks/splits a bit when I cut it, and I think that this might cause an excessive amount of comp to burn while the star is still in or close to the shell when it breaks.

I'm wondering what would cause my comp to split like this, and how I can remedy it. I've really only noticed it with comps that contain a fair amount of charcoal, and not so much with comps like KNO3 White, which is mostly KNO3 and sulfur. My stars are 1/4", if that makes any difference. I would say that the comp is too dry, but I don't think that's it, because if I add more water then the comp will get too wet to cut.

[gregh]

You might try making a dextrin liquor by dissolving the dextrin in the water before you add it to the dry comp. This method ensures the dextrin is activated and will make it a little stickier. Another option is to use a different binder like SGRS or starpol. I have always had good luck with those two. Also, the best advice I can give you is to make a frame or a loaf box. With those, you can actually compact the comp solidly in that shape and not have to worry about cracking around the edges. Or you could use the baggie method. So many options. Here is a link where you can see Paul Moulder using a frame.