A tube stay mounting assembly includes a press assembly having a housing and a top block configured to flatten fins on a first surface of a finned tube. A press arm is operable to move the top block vertically with respect to the housing. A bottom block is configured to flatten fins on a second surface of the finned tube when the press arm is rotated and moves the top block downwardly. A tube stay clamping assembly includes a clamping housing configured to receive a tube stay having a top, bottom, rear, and front walls, the tube stay being configured to receive a flattened portion of the finned tube. A clamping arm is connected by linking arms to a clamping block, the clamping block configured to engage and force the front wall into snap-fit engagement with the top wall of the tube stay.