Speed Demon News: Rust Proofing Your Trans Am
By: Patrick Smith
(ďNo statue was ever erected to the man or woman who thought it best to leave well enough alone.Ē)
George Walker, Ford Styling Director
Pontiac Trans Am owners know what rust buckets they can be if theyíre not maintained. Young enthusiasts born during the last fifteen years wonít likely remember that Trans Ams were just used cars then. People bought them on payment plans, drove them in the winter, beat on them mercilessly in street races, had accidents and did repair jobs. If it was on its fourth owner, the car was a bit ropey in terms of mechanical condition or the paint is a bit thin. Young owners may not have had the money needed to keep it up. The end result was a tired looking car in need of bodywork by the time a TA enthusiast gets around to restoring it.
Once youíve restored a car, you want to keep it looking its best. A bare metal re spray isnít cheap. If body work was needed the bills add up fast. Rust never sleeps. If your car was sold new with a rust proofing package, it likely has been drilled in certain areas to allow access to inner metal panels for rust spraying. Using those holes will make the job easier for your home maintenance operation. Iíve come up with my own routine to rust check TAs, even ones that were never drilled. Youíd be surprised how many ways you can apply a coating using existing holes, crevices and gaps. .
Two Kinds of Rust Corrosion: We all know about the horrible effects salt has on car panels. We easily forget a form of rust common to coastal regions. Salt water aerates and turns into mist which settles inside body panels during the warm days, then condenses into droplets at night time. Repeated exposure to salt laden air will rust a TA from the inside out within years.
Notice how rust is severe in the lowest areas of sheet metal; this is classic condensation cycle rust.
Unlike Northern cars, coastal salt rusting tends to eat up windshield pillars, entire roof panels on targa cars, trunk lids, upper fenders and hoods. The middle and upper panels are just as susceptible to rust on a coastal car as the floor pans on a Northern car. Northern Texas also have condensation rust cycles due to wide temperature variations. Iíve seen cars from Lubbock with rusty chrome seat belt buckles and dash trim caused by sweating on the trim during cool nights. The condensation cycle is what youíre combating.
Trans Am Weak Spots: The TA has certain weak areas you have to watch out for. The rear fender spoilers trap debris between the plastic spoiler and the metal wheel well arch. Water and dirt stays behind and starts eating away the metal. It is largely hidden rust until it breaks through the other side or migrates above the spoiler trim. A business card pushed in between the spoiler and the metal will give you an idea what kind of dirt is hiding there. If you pull it out and itís smeared in junk, itís time to unbolt the spoiler and give the area a good cleaning. The front fenders around the scoop and behind the wheel arch are rust magnets.
Scoop mounting area and lower fender wheel well panel is very prone to rust. Lots of spray is needed here.
When choosing rust proofing spray I use Krown, but if you have a favorite by all means use it. I use a liquid version so it can creep along body panels. Wax-Oil type solutions wonít spread as far once it cools. This includes products like Dinitrol or Waxoyl. They require heat, specialized rods for inner door panels and a compressor. If you have the gear itís a good system. Iíve used them when working at dealerships.
Start by accessing the metal behind the spoiler by removing the B-pillar ventilation port and spraying your rust proofing material inside. Spray in an arc upwards towards the sail panel. Spray towards the rear of the car against the wheel well, turn downwards to spray the rocker floor and inner B pillar which includes the bolts holding the spoiler on. It isnít a wide area to cover, but it does protect the sail panel and roof area which on a targa car is quite vulnerable. The Krown stubby can is ideal for this area.
Inner fender bolts, scoop bolts, mud flaps and moisture fostered this rust section.
The rocker rails are noted for rusting thanks to Pontiacís method of using plain sheet metal wire conduit covers under the door sill plates. The original sill plates were aluminum and when they rested against plain metal, corrosion occurred because of bi metal dissimilarity and exposure to water. That chalky white powder you see on old TAs next to crumbling sill plates was once metal. Bad corrosion will make the conduits disappear and attack the rocker panels. Removing the sill panels allows you to check out whatís going on. For rust proofing, use the existing screw holes with a 360 degree spray pattern. If the rocker has been drilled, there will be access holes on the lower sides as well as the arches on the rear door side. On 1980 and earlier TAs, you can spray inside the front fenders going between the door hinges with a spray gun. After spraying the rear of the front fenders, you can spray the upper fender crowns by going in through the vents on the fenders. I also spray the wheel well splash shields. The front part of the fenders are easily accessed through the engine bay area. A small spray can allows good access right up to the rad cradle.
The hood has access holes under all the major braces and along the crimped sheet metal edges. I spray inside the holes. I concentrate on the brace areas. Engine heat should protect the flat sheet metal but Iíve seen them rust there too. (trans am hood rust pic) Hidden covers are the worry spots. If the passenger doors have been drilled for rust proofing you can use those entry areas. Since the door is so wide, effective spraying isnít easily done with home tools. I only spray the bottom ledge going through the drain holes.
The cowl area is accessed by removing the plastic debris cover and spraying undersides and floor of cowl. You can actually reach into the metal portion of the dash panel behind the windshield, a notorious rot spot. A nice tip for car buyers, feel around on the driver side cowl area for the rivets on the VIN tag. If theyíve been messed with or feel like hardware store rivets, start asking questions. I skip spraying the firewall because engine heat and its proximity to firewall makes spraying useless. If your Firebird had a leaky rear main seal, chances are good the firewall and toe boards are rust free.
This body vent outlet is where you apply your rust proofing spray for front of rear quarter. The trunk area is where you access the rear inner quarter panel.
The next area is the trunk. Again, I spray the braced areas of trunk lid and the torsion bar rods where exposed. Spray the drop off panels on both sides, go forwards and spray the wheel well between inner quarter panel and well. If thereís a bit of dry scaling under your parcel tray, nowís the time to protect it. Donít spray, instead soak a rag with penetrant and rub the area down. Most cars have speakers there and it could get messy. I also do a light spray of the quarter panel arches from the rear window to the tail light panel.
All thatís left is the underside. Everything gets done when you take it to a shop. Thatís the best method as well. Youíre done protecting your car at a significant savings. Here are a few details you should know as well.
If youíre unsure about what kind of bodywork has been done on your car, consider just doing a floor pan and chassis spray until youíve been able to determine if thereís much body filler under the paint. Filler if left exposed under a panel may absorb water and contaminate your paint finish. A black car may develop micro spots of rainbow colored pimples if rust proofed over exposed filler. The panel should be removed and properly refinished before rust proofing.
On hatch roof cars, how does one rustproof the targa structure? It depends on how much work youíre willing to do. Early Hurst hatch cars often had solid pieces of some kind of reinforcement baffle installed behind the trim plates. There wouldnít be much space to spray any mixture in there. On Fisher hatch panel cars, the bracing is a rib hidden under the headliner. On double paneled roof cars, it isnít readily accessible unless youíre doing a headliner restoration. Until then youíll have to be content with a sail panel spray and hope the fog of oil reaches high enough.
This is what happens when you just ignore the bubbles then cover it up. Good Bandit owners don't let this happen to their cars..