"We knew he had that sort of potential but you can never be sure they will produce it on the big day," Quinn said.
"He seems to thrive on pressure, the big occasions don't seem to worry him."
It was Quinn who suggested Capes should have a crack at power lifting after coaching him in the hammer throw.
He was good enough in that sport to come third in the senior boys event at the North Island secondary schools championships but his build was always likely to count against him developing into a top-liner.
"He's absolutely mad on the gym and has such a great work ethic I could see him doing well in power lifting," Quinn said.
"He's on a level footing there because they compete in their own weight groups, it suits him perfectly."
Capes will head to Palmerston North this coming weekend to contest the Central Districts bench press championships.