Andrew R Stewart 

I'll just underline the OP's comment about the contact surface area amount need. A simple method of figuring out the contact surface needed might be to push the math of brazed drop out connections and the tensile strength of the filler used then compare to the strength of the intended glue/epoxy. Of course when in doubt do destructive testing of test pieces after doing so with brazed or bonded samples from known sources. But this step is too costly and/or time consuming for many from what I read often on these forums... Andy.