Light to moderate clamp pressure, very even glue coverage on BOTH pieces, and I sand my surfaces with 80 grit lightly. I believe "smooth surfaces" really means flat, well mated surfaces. Thats why I choose to lightly sand. I also prefer 2" c-clamps and spring clamps over rubber hose or tube. I have 30-35 of them I use every few inches up and down the limbs. Also be extra, super darn sure your mating surfaces are flat and not convexed or concaved. That will blow a backed bow quicker than the "wrong" glue will. After Im done securing it with clamps I like to peer all the way around the rig a few times to be sure glue is oozing out and I can see no air at all between backer and core. Then just twiddle my thumbs for 24 hours while it dries.