In answer to your question: Yes, it will be a problem if the dowel rod is smaller than the opening of the pool noodle. However, I use this method of basting exclusively now without the dowel rods. I use three pool noodles: one each for the Backing, Batting, and Top and marked a center line on each noodle. Then I pin the very edge of the backing/batting/top along this line and roll it up. I then spray baste the layers together and within a few minutes I'm done. For added security, I pin the perimeter of the sandwich and cut off any unnecessary access fabric/batting. Love this basting method!