I use Lord Fusor. 3m, Sem Products, they are all good. We tested the Fusor. We glued 2 welding coupons together and pulled them apart on the frame rack. The metal failed. The overlapped glue joint was stronger. There are glass beads in the glue that significantly reduces the possibility of over clamping the products ability to squeeze out. You can hear it crunching when you clamp it. Adequate clamping is a must. Plastic filler does not like to stick to it.