The article underneath was written by me in 1999 when I was still a
mobile operation, before moving to my first premises in Newbury when I still though of
myself as a Classic Car and Jaguar specialist. Re-reading it now, I think it's still a
good article so I have included it in the archives from the old website. I am now
chiefly a Land Rover and Motor Home specialist but I don't turn any vehicles away
(unless the underside has been molested with schutz or corrosion damage has been bodged
– see my terms and conditions.) I have included some old “advertorial” ads from Land
Rover Owner magazine in the archives and these continue the story about Land Rovers and
corrosion.
Vehicle Corrosion and Car construction post war
- British (and European) Classics of the ‘50's
- Cars of this era carried on the pre-war construction of a body
on a chassis although the bodies were now generally made of pressed steel rather
than hand crafted aluminium over ash frames. The quality of chassis construction
on some of the up-market cars of this era is something to behold, with chassis
members being "vacuum welded": welding gas passed over the whole of the piece
under fabrication while it was welded, meaning that the chassis member is sealed
without any oxygen inside, making corrosion from the inside impossible.
Unfortunately quite often this beautiful craftsmanship has been unwittingly
vandalised in modern times by drilling holes for brackets to hold new brake
lines etc. Cars of this era did not have sills as we know them of course but
some of them have terrible mud traps and it can take hours to clean out all the
accumulated silt!
- British (and European) Classics of the ‘60s and 70's.
- Monocoque construction was new in the ‘60s & ‘70s and car
designers had little experience of this new form of construction. Their main
pre-occupation was making sure the car body was strong enough. Consequently,
cars of this era are over-engineered and make good subjects for restoration.
Little thought was given to how to protect the cars against corrosion and any
thinking on this subject seems to have been mistaken. In particular, it seems
that cars of this era had terrible water traps. The thinking at that time was to
seal everything up as much as possible. Vents at the bottom of doors and in
sills and box sections underneath are always inadequate, especially on Jaguars.
The Mk2 for example has one little 1/4 inch drain hole for the whole of the"
vestigial" chassis member which runs from the front bumper to the rear axle. It
seems that no distinction was made between the harmful oxygen which feeds the
rust process (which is going to be present anyway) and the beneficial currents
of air which quickly dry out condensation and moisture. Apparently designers
were terrified of water getting in from underneath the car and wanted to stop
this happening by sealing everything up, when they should in fact have been
making large holes everywhere to let moisture drain out and let plenty of air in
to dry out the cavities
- Underseal Before the advent of the (generally excellent)
modern polyurethane underseals in the late ‘70's, cars were undersealed with a
bitumen type underseal. Bitumen underseal is pretty poor stuff and soon dries up
and flakes off. Many cars of this era were"tarted up" underneath with bitumen
underseal (A favourite trick of unscupulous car dealers of the period.) Bitumen
applied to a rusty surface is an absolute disaster and will aggravate the
problem while hiding it for two or three years until it starts to fall off in
strips. When buying a car, if you are confronted with a car that has a recent
application of bitumen underseal, even if it seems to be part of a legitimate
restoration, I would walk away. By now any competent restorer should know that
bitumen underseal is not the product to use. (By the way I am always happy to
give free advice over the phone if you are thinking of buying a car.)
- American Cars.
- Monocoque construction is something the Americans seem to have
ignored through the sixties and seventies and most of the eighties. Cars
continued to be built the "Good Old American Way" on a good old "frame". From
having rustproofed many American cars it seems to me that the real American car
making giant (which no-one has ever heard of!) is "Fisher Bodies" because all of
the American cars of any period of the sixties and seventies are just variations
on a theme built by Fisher Bodies! These cars are very simply and very solidly
built and are generally extremely well designed to keep corrosion at bay. Most
of the box sections underneath are three sided so there is no question of
festering damp corroding the box sections because everything dries out very
quickly. There are no complicated spot-welded seams. Panels are meaty and thick
and welding is always very "butch" and agricultural but effective. Cavities are
well ventilated prairie-like expanses of space where any moisture is going to
dry off very quickly. All this will surprise some people who may have childhood
memories of the few yanks they saw being terrible old rust buckets. I can
explain this seeming anomaly. North America is a continent with extreme
variations of climate. Cars which live in the Sunbelt for instance, particularly
in places like Arizona just never rust! California is so full of old cars that
they don’t know what to do with them - so they flog them to us!. If you live in
Canada on the other hand, your chief pre-occupation will be how to stop your car
rusting to pieces.
- "Feast or Famine"
- Cars in the US come off the production line with no
protection on them whatsoever. In many cases the only thing protecting the steel
underneath is a very thin coat of primer! If you live in the Sunbelt this is of
no concern to you at all. If however you live where winters are severe and
summers are wet, when you order your new car, you specify "Winter Protection" .
American anti-corrosion protection is really superb. Many people will remember
Ziebart from the 70's. This was a typical American anti-corrosion system
(although the materials were made over here under license and suffered somewhat
in the translation I fear, as did the control over franchisees). Whereas we were
undersealing our cars with horrible, nasty, cheap bitumen, the Americans, since
the ‘40s were using a beautiful, highly formulated "hot melt" with no bitumen in
it whatsoever. This was sprayed on at 80 degrees C! I have seen forty year old
American cars with this protection on them and there is not the slightest sign
of deterioration of the coating and not a speck of rust underneath and even
wheelarches usually show little sign of damage (although the coating always
looks very grey and shabby.) The ideal situation, of course, is to live in
California and have a vehicle with a proper American anti-corrosion treatment.
Now if you live in soggy old England and you import a car from the American
Sunbelt, the 64.000 dollar question is "does it have "Winter protection"! If it
does not you had better get on the phone to me right away! Even if it does - it
is still a must to have your treasured vehicle properly "Before ‘n’ Aftered".
- It should be noted of course that the traditional American
types of rustproofing were really only suitable for new cars. Car designers
nowadays have learnt an awful lot about how to make monocoque bodies that do not
rust (unlike the cars of the 60's and 70's). They are therefore able to offer 6
year anti-corrosion warranties. With the Classic Cars that I rustproof, there is
usually quite a lot of rust already present and there is in my opinion only one
rustproofing material that will kill existing rust and that is Waxoyl. The
traditional American "Hot Melt" types are just not penetrative enough and will
not "wet" the surface enough to work on rust. (See "Why Waxoyl") Note: This
was written in 1999. I recommend my new, improved coatings nowadays. They
are similar to waxoyl.
- Modern Cars
- From the eighties onwards, cars were built without the
terrible water traps of the '60's and '70's. Cad-cam design now made it much
easier to make a simple, light body with enough strength. On the smaller cars,
front wheel arches were no longer a structural part of the car and could be
lined with non-rusting plastic liners which would stand up to any amount of
abrasion. Recesses at the bottom of the wings behind the wheelarch liners were
open, meaning no more fatal build up of mud and silt to rot away the bottom of
the wings. With cad-cam design cars can be designed to have a specific life
span. I believe most small and mid-range cars are now made to last for exactly
six years. Everything: bodywork, mechanicals, upholstery will hold up well for
around 6 years and then quickly deteriorate. Some owners of modern cars intend
to look after their cars very carefully and keep their cars a lot longer than
the manufacturers consider to be a normal life span. In these cases my services
can definitely help to prolong the life of the body.
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