Written by Jim Dutton
When I started closing the vertical stab I decided it would be easier if I did not get in my own way while trying to install the foam shearweb and closeout laminates. I went to good old Home Depot and found a six foot long piece of square steel tubing – 1″ square, 1/8″ wall thickness. You can make sure it is straight by holding another piece up against it before you buy it. Cut it into two 3 foot long pieces. Hot glue the top and bottom spacer blocks in place per the instructions. Cut a piece of 1″x1″ aluminum angle, the length is slightly less than the distance between the spacer blocks.
Clean the square tubing and the aft 2 inches of the outer skins of the vertical stab to ensure hot glue will adhere well. Using at least 3 c-clamps, sandwich one of the vertical stabilizer skins between the piece of aluminum angle(inside between the spacer blocks) and one of the 3-foot long pieces of square tubing(on the outside). The square tubing should be about 3/4 of an inch ahead of the opening. Hot glue the square tubing to the vertical stabilizer skin with generous beads (full length) on both sides of the square tubing. Remove the c- clamps and aluminum angle. Apply the other piece of square tubing to the other side of the vertical stabilizer in the same manner. You should ensure the vertical stab remains plumb during this process.
Now, you have stabilized the opening. Leave the spacer blocks in place and install the foam shearweb. They will be a minor inconvenience but you can work around them. Once the foam shearweb is in place (Qcelled in) you can remove the spacer blocks and install all the laminates. I removed the square tubing just prior to riveting the rudder hinge.
If you do it this way you have nothing in your way, a clean canvas so to speak. You don’t have to worry about clamping fresh laminates, squeezing out resin with clamp pressure and unsticking things after the resin has cured.