Started by taking long strips of 1/2x1/8 and cutting them in 4 and 3/4 inch pieces. Some of the peices need to be 6". Some of the spacers are 1/2x1/4 depending on the area it is in being installed at. The point is to make one smooth surface for the rib attach angle to mount to. The strips do provide strength also Spacers go on both sides of the spar regardless if there is a rib on both sides..
