Image 6 in the previous blog post show the three parts creating the cross beam. In part 2 is a hole, one in each end, near the end of the panel. These holes are for the front anti roll bar screws, see image 2 in blog 1. The problem is to know the position of the holes, a problem solved in the following way:
Slits was made with a hacksaw in the ends of two 1” long pieces from a M8 threaded rod or the threaded parts of two screws, image 1. During the work the threaded pieces was held in a stud connector nut locked by a normal nut. In the next step they were held in the chuck in an engineers` drill press and grinded conical in the slit ends, image 2.
The “screw” was then screwed in place in the anti roll bar nuts with a small screwdriver with the conical end protruding approximately 1 millimeter, image 3 and 4. With a firm blow with a plastic hammer, image 4 and 5, a center punch impression was created in the sheet, image 6. Two holes was drilled in the impressions and enlarged to ½” with a screw hole punch, see image 6 in the previous blog post. The length of part 3 in the same figure was carefully adjusted to fit between the longitudinal boxes.
With theparts prepared time has come for joining them with the spot welder, image 7, creating a box section. A box section made this way is very strong despite the thin walls. Unfortunately, with time a closed box section like this have a tendency to be weakened by rust from the inside. The cause is the humidity created by the environment and its changes in temperature, a well known process described in the book. But, there is an easy cure for the problem: inside rust proofing and some ventilation keep the box healthy for a long time. When the repair work is completed we will put some light on the rust proofing process and the equipment used.
Before connecting the manufactured beam to the body, three ventilation openings were created. This work started by drilling two 7 mm holes for every ventilation opening in the bottom of the beam, image 8. The distance between the holes was approximately 15 millimeters. With a very slim blade in the air saw the sheet metal between the two holes were removed, image 9. Finally the three openings were covered by a sheet strip brazed in place, image 10. Later, at the same time as the rust-proofing process is discussed, even the choice of air saw blade will be discussed.