I'm designing the leg for a bed loft and was planning on laminating together 4 1x4's of Poplar. The middle two boards would not go the full length of the leg, so that a 2x6 can slide into it. This 2x6 would be what forms the length of the bed on each side. I am wondering if wood glue on the faces of the 1x4's would make it strong enough, or if I should drill a hole through all 4 of them about every foot and glue in a wooden dowel. Would the dowel help or would drilling the hole just hurt the integrity of the boards and create more work for myself?
Also, the 2x6 will be running the length of the mattress and supporting most of the weight (along with its parallel one on the other side of the bed, about 7ft long). Is a 2x6 overkill and would a 1x6 suffice (dropping the legs to be three 1x4's instead)?