Completion of the box section, creating ventilation openings

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.

Image 1 A slit was made by a hack saw in the end of the threaded pin.
Image 2 The slit end is grinded to a point.

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.

Image 3 The "screw" is screwed into its place.
Image 4 A plastic mallet is used to create a impression from the “screw” in the sheet.
Image 5 The mallet create the impression by a firm blow.
Image 6 The impression in reality.

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.

Image 7 The main parts are spot welded together.

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.

Image 8 Two hole is drilled and the dotted line show where the sawing is intended to be done.
Image 9 A strip of sheet is shaped and ready to braze.
Image 10 The box section with ventilation openings is ready to fit.

Panel Beating Doctor Bengt Blad

At this point in my life when I was about three quarters through the medical schooI I discovered the English wheel and the Eckold machine, and, one thing leading to another - no more time for med school.

More about the book

This book, with around 1,500 pages of reader-friendly text and about as many illustrations, is a summary of 40 years of working with vintage, collectors' and racing cars.