EK283 wrote:Guys,
The cars rust originally because they are not treated in any way from factory. Ever noticed why all rust spots are in the same places on all the cars. I have cut up a couple of rusted and damaged ek's and have noticed that there are bare metal parts especially where the double panels exist, roof, sills A B and C pillars.
There is a paint product called weld through and it is similar to cold gal but it will still burn off with enough heat.
Greg's Hit the Nail on the head here,
Most rust is caused not from just untreated panels, but the way the panels are joined and made from factory.
You need good ventilation and adequate drainage to prevent further corrosion of the panels, with all the old cars in the day being built, there was no consideration for the way panels were joined and overlapped and positioned. Most joins were in very low areas and and allowing pooling water to sit, also excess build up of braze to join panels in places and then the use of bitumen base sealer promoted early corrosion of the panels,
It is all here where the rust begins at a very early stage.
Examples of the areas that were submitted to water and no drainage or ventilation, that most of us here have all experienced are:
Lower front and rear Windscreen corner surrounds.
Boot rubber channel.
Front subframe to firewall.
Front inner sill and rear sill.
And of course on nealy all vehicles, lower front guards and rear 1/4 sections.
If you car was parked under a tree or lean to, without having the gutters cleaned out, the roof was prone also.
Now this does not take into consideration, with the lower subframe or chassis rail, where the maker fails to provide adequate drain holes and ventilation to prevent further rusting.
Don't get me wrong here fellas in what I'm saying, cause that brand new car you may have just bought or bought a few years ago has probably got early stages of corrosion in her already, it just hasn't come through the outer panel yet.
I personally have seen many Late model Falcons, Astras, Barinas, and even New Commodore with rust.
Bad flaws in design are still present, in virtually all makes and with makers opting for large plastic covers to actually cover a lot of the vacated holes in and around the windscreen, inner guards and drainage areas etc: just to make it visually appealing for the purchaser. It leaves great areas that are sight unseen for bad news.
And its these points that corrosion begins, you may think debris, leaves, gumnuts can't get in there, but they do, and when they decay. It becomes a super moist environment for the beginnings of corrosion, because you can't see it, why is the need to clean it.
Pull one of those inner guards off, and just see how much shit gets in there.
Now getting back to welding a panel, if you do treat it with fish oil or the use of weld through primer, you should slow the corrosion process down considerably. But 2 things will happen in all steel that you weld or use heat on. The natural oils from steel, bleed out of the panel or piece to be welded, And the steel becomes carbon ed, so becomes more porous. Hence oxygen can get in there much quicker. Thats why if you cut a piece of steel with the Oxy or heat it, you will see corrosion start on the Heated or cut sections, or the freshly welded pieces.
The best and cheapest way I found is to retreat the metal with used Sump oil, on both surfaces, whilst the panel is still warm. It will blacken the surface and leave a carbon like coating which is resistant to corrosion, and you can clean the sump oil of prior to painting anyways.
I don't plug any products, but the Wurth weld through primer is pretty good. I now Por make a product for the same use, but I have yet to have some experience with it.
Regards John
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by drilling regular spaced holes and saturation spraying a product through these holes.