This bench had been out in the weather in the Northern Cascades for many years. The surviving slats were cracked and rotting. White oak was chosen as it is strong and does reasonably well outside. New slats were cut, drilled, and finished at the workshop. The new slats were made as thick as the castings could accommodate for strength and durability. The tight fit made assembly a little tricky, but the new boards should be good for many years, especially if they are periodically refinished.
