Authenticity or efficiency
Chapter 1: Nuts and bolts
by Walt Brewer
Sometimes when you are restoring your old Caddy or LaSalle you have to make some choices. Many of these choices should be made before you actually start your project.
There are two extremes, one being to disregard originality and go totally for performance and efficiency. This extreme will probably put you into the “street rod” category. The other extreme is to be an absolute purist as to originality, using only NOS parts.
This extreme usually means a primary concern of a 100-point car that will be transported to and from shows and driven only from the trailer to the show area and back to the trailer. Many times this will sacrifice reliability, efficiency and maybe even safety. Fortunately, there is a complete spectrum between these two extremes that you can choose from.
The choice is yours and comes quite often during the course of your restoration project, whether you do it yourself or pay to have to have it done.
Most of us want to keep the car as close to original as possible, but also want to be able to drive and enjoy the car on tours and club events with the highest degree of dependability and safety.
Getting down to nuts and bolts, your pre-1949 cars have more of a problem than the later cars when it comes to the “nuts and bolts.” Nearly all bolts you buy today are “graded,” which by law have to be clearly marked as to their “grade” or quality. The lower the grade number the lower the quality and strength. These markings, when seen by purist judges, may cost you a point or two.
Personally, I like the idea of new high-grade bolts and nuts everywhere, if at all possible. The reason is very simple. Bolts that are over 50 years old have that been “torqued” down and subjected to extremes of hot and cold have a tendency to weaken or crystallize.
They may be OK as long as they are not disturbed, but once taken out and then cleaned up and reinstalled to the proper torque, they can fail at very inopportune times.
When the factory made these older cars, they had bolts and nuts made by the millions for each specific use rather than using available standards. These exact bolts are no longer available as a rule, but you can come close. Head bolts are a good example. The closest you can come is 1/8 inch longer and one size smaller head. This necessitates using a stainless steel flat washer. If you look hard enough, you can find these with a black finish, if not, you can get a bottle of gun bluing and use it to get the right color.
A little trick I like to use when taking out old bolts and nuts is to put them in a baggie, mark them and find replacements, putting them in a baggie with the old ones until actual reassembly occurs. This will enable you to make any necessary adjustments.
Although some of the original bolts had some special markings on them, many were plain. The modern bolts can be modified to look original by using a very fine grinding wheel to take off most of the grade marks. Then use a crocus cloth strip on a flat surface to rub out the grinding wheel marks followed by a polishing wheel with steel polishing compound.
After cleaning well, use the gun bluing to obtain the dark original color. Since you have removed all the original plating, you should heat the head of the bolt slightly and dip it into wax—allow to dry thoroughly before wiping. This will delay rusting for quite a while. You may want to have them cadmium- or zinc-plated if you want a bright finish.
Granted, some of these processes can be very labor intensive, but in the average car restoration, the cost of new nuts and bolts throughout will be less than $100, but could save you thousands in later unwanted repairs. I always use at least grade 5 and grade 8 on critical or high-stress locations such as front suspension motor mounts, etc. You will find you will be better off and get a better selection if you go to a specialized bolt and nut or fastener dealer rather than your local hardware store or lumberyard.
We will talk more on authenticity or efficiency in other components in the future—meantime, remember a chain is only as strong as its weakest link.
See ya next month.