<VV> Artzberger on Painted Hexes

[N. Joseph Potts]

I posted a question about painting bolt heads here a few days ago, and got
ZERO responses. One of several good possible reasons for this is that I
asked for a pointer to a past Communique article on the subject, and my
search of my 50 or so past issues turned up nothing resembling what I
remembered.
     I JUST found what I remembered in the Auto Restorer Magazine for July
2003, as a Reader's Tip from none other than Bill Artzberger of Corvair...A
History and Restoration Guide and other fame.
     At the risk of violating his or someone else's copyright, I'll here
post his tip, as evidence that, although my memory has almost finished
disappearing, I am still not entirely crazy:

Protect Painted Nuts & Bolts
     One of the frustrating problems that I have had through my years of
restoring automotibles is chipping the paint from freshly painted nuts and
bolts while tightening them in place.
     So, I recently decided that some experiments were in order before my
next attempts. I soon discovered that not only was the paint chipping, the
primer/surfacer was also chipping to the bare metal. With that, two things
became apparent. Thick paint is not acceptable and a primer/surfacer should
not be used on nuts and bolts.
     My conclusion is that there is no need for a primer/surfacer on any
area that does not need to be sanded to a smooth surface for painting.
Therefore, the first step was to eliminate priming the bare surface of any
nuts or bolts.
     In place of any primers, metal cleaner and metal conditioner was used
[I don't know what these are - NJP]. This provided a clean thin coating of
zinc phosphate on the surfaces which should diminish rust problems to near
zero.
     The second step in the process was to spray two very thin coats of
catalyzed urethane [I don't know what this is, but I THINK it's colored
paint] on the nut and bolt surfaces, allowing a longer than normal dry-time
between coats.
     After a few days of dry-time in temperatures above 70 degrees and
humidity of less than 60%, it was time to test this theory by tightening
(torque to 50 lbs.) some nuts on engine block studs.
     The nuts were first wrapped with two layers of medium-heavy plastic
strips cut from plastic bags used in breakfast cereal boxes. The nuts were
first torqued to 40 lbs. An inspection was made and the results were
positive.
     The nuts were then torqued to 50 lbs. A careful inspection showed no
chipping of paint on any of the 24 nuts. I should also mention that a thin
layer of grease was used between the cylinder head nuts and the cylinder
head.
     At this point and after a full summer of driving, there is no sign of
paint chipping on the cylinder head nuts.
     (It is possible the PPG DP40 or DuPont Vari-Prime [I suppose these are
primers, to use after all - NJP] would also work well on nuts or bolts to be
painted. I'll try that and report on my results.)

     As you can see from my [remarks], I don't find this advice readily
actionable, but if it's possible to use it with a spray can of lacquer, I'm
certainly interested in the results claimed.

Joe Potts
Miami, Florida USA
1966 Corsa coupe 140hp 4-speed with A/C