Exterior car siding clear coat needed

[Blackberry]

We’ve added a gable end to the house and covered the patio. I helped... but hired a contractor to do the majority of the work, he did a great job. Now comes the need to clear coat the bare  beatle kill pine ceiling. I’d like to seal the wood in an effort to prevent graying and maintain the look. Additionally I’d like to discourage carpenter bees. It’s undercover from the sun and approximately 480 sq feet. Any suggestions on product?