Cathedral windows project bag

I spent the whole morning cutting out 1500-2inch squares for a cathedral windows wall hanging I would like for my classroom. I spent another couple of hours ironing the squares into triangles and the rest of the afternoon trying to put them together. Because I am sewing through 6 layers the seam is so thick it is causing my sewing machines to overload. This is so odd since I constantly create cathedral windows and I have never had this happen. I realized the overload is because I am using a fabric from joann's called quilters cotton and it is not as nice as the Kona I am used to using. Thank heavens I only purchased enough for this project.