Here is how I keep it from splintering the back with out clamping. Take a very small drill bit 1/16" and drill in the center of the circle. Then start drilling with the larger forstner bit about half way thru the wood. Stop turn the wood over. You will have the small hole showing you the center of the circle. Continue to drill with the forstner bit thru the opposite side. Ta da, you now have a hole with no splintering.