Then a scarf joint may make a difference. The board is too short, make it longer, The beam won't span, lengthen it. Building a boat, you will need this joint. Japanese joinery has taken the scarf joint to new levels with their elaborate puzzle like joints many don't even use an adhesive and the joint lines are just things of beauty. Explore You Tube for some really outrageous examples. For every day use in the shop or trimout job see these URLs
http://www.finewoodworking.com/2005/10/ ... arf-joints This URL is for a members only site but the jig idea is good
http://sawdustmaking.com/woodjoints/scarf.htm