epoxy and fiberglass matt

[71kidcasper]

I have been fiberglassing for several years with polyester resin and building things with epoxy. Now that I am using the two together I am finding out that epoxy does not break down the chemical that hold matt together. I am having trouble going around corners with it. Are there some tricks to this or is there a different matt I should be using. In the past when I was using polyester I seemed to be able to shape it any way I wanted to.