In the past I have sistered lumber by putting the two pieces side by side (so if you have two 2x6s putting the 6” side next to each other) with some liquid nails on them and then putting some nails through them to connect them.
But now I’m in a situation where I’d like to join the 2x4s on top of each other - so essentially taking two 2x4s and creating a 2x8 from them.
At first I was thinking I would just get some Simpson nail plates and go all the way down the length of the seam where the boards touch on both sides, but I was worried that wouldn’t provide enough support. My other thought was to run a ~6” piece of 1/2” plywood the length of the seam where the boards touch on both sides and put nails through the plywood and 2x4s to connect them
Would either of these methods work for connecting two 2x4s on top of each other? Is there a better method that I should use instead?