A rail support system includes a clamp side having a channel with a first side and a second side, the first side and second side to engage around a post; an extension extending away from the second side; a plate engaged with the extension; a tightening screw engaged with the plate and further engaged with the first side; tightening the tightening screw pulls the first side and the second side together; a cradle side having an arm attached to the channel and extending away therefrom; and a cradle support attached to and extending away from the arm; the cradle support is to receive a rail; the clamp side is to secure to post while the cradle side is configured to engage with the rail such that the post and the rail are held in position for welding together.