The outer bush for the strut attach bracket was first drilled through using a 3/8" hole
in my jig block as a guide to make sure the hole was perpendicular. Then the other bush was match drilled about 1/4" deep to establish the hole location. The bracket was removed and this was then also drilled through using the jig block. This worked well to keep the spacing and alignment of the holes accurate and the bottom bracket fitted nicely over the bolts. Then the upper 1/4" thick 12-ply plate was glued to the spar. Once the glue was set the brackets could be bolted into position. The bushing material is very solid and it was possible to torque the bolts to the specified torque for a 3/8" bolt of 160 in/lb without compressing the wood of the spar.
The outer bush for the strut attach bracket was first drilled through using a 3/8" hole
in my jig block as a guide to make sure the hole was perpendicular. Then the other bush was match drilled about 1/4" deep to establish the hole location. The bracket was removed and this was then also drilled through using the jig block. This worked well to keep the spacing and alignment of the holes accurate and the bottom bracket fitted nicely over the bolts. Then the upper 1/4" thick 12-ply plate was glued to the spar. Once the glue was set the brackets could be bolted into position. The bushing material is very solid and it was possible to torque the bolts to the specified torque for a 3/8" bolt of 160 in/lb without compressing the wood of the spar.
