Thanks everyone. I don't know what size my crochet thread is. Our puppy got a hold of the ball and tore the label off. The thread goes through fine, but I agree with Jingle, the big eye of the needle makes it hard to pass it through the layers. I keep my leather thimble on the whole time and that helps.
How are you ending your threads? I'm just taking a tiny stitch (as tiny as can be expected with such thick thread,) then run it through in between the layers, pull it back up and snip it off.
~ C