Repairing the Cowl Part 2

The driver side rust hole

Before I weld in the floor brace, and the floor pan, I wanted to repair the cowl area as it has a few rust issues.  The Cowl for a 1969 – 70 is only sold assembled as one piece, it’s also expensive.  Since my cowl only has a few pinholes, and one rust hole someone tried to repair with bondo a long time ago, I decided to fix-it.

First up is the passenger side, the vent tube where the heater core draws air, has a few pinholes.  using my media blaster, I hit the cowl area, and stripped away the black paint that was applied to the inside of the cowl.  I also went after it with a wire brush on the inside of the passenger compartment. Once the loose rust and paint was removed.  I masked off the bottom of the cowl inside the passenger compartment.  This will keep the rubberized rust encapsulator from leaking through.

I used Eastwood’s Rubberized Rust Encapsulator Undercoating I used one of the 24″ nozzles that can with a can rust Encapsulator that I plan to use to coat in the vent area.  This worked great as you can see in the photos.  I put a good thick coat on, then went over it with a brush to even it out and work it in any pinholes.  To help me check that I got all the holes, I used a bright halogen light in the passenger compartment pointing at the cowl.  then from the engine bay side I checked for any light. Once I was happy that no light was getting in, I left it dry for 24 hours.  Then removed the masking tape.

Using a wire wheel, I did the rest of the cowl to remove mostly surface rust.  Once this was complete I could see the extent of the hole on the drivers side.  I’m still baffled how the rust hole formed on the highest spot on the drivers side.  you can see the lowest part is still good, just some surface rust.

Using a paint pen I marked the area to cut out, making sure to get far enough away from the rust to have good metal.  I then cut out the rust, using an air body saw (Like a small sawzall).  Just for teh picture I put the bondo plug back in to show what it looked like.  When I first saw it under the dash I thought It was another mud dauber nest and tried to knock it off.  I have no idea how long that was there, but as you can see but the rust holes around it, Bondo is not a good rust coating.

Using the cutout metal, I made a cardboard template of the right shape.  Once I was happy that it was a close match to the original.  I used it to cut out a part from flat steel.  I left a good margin on the metal patch to overlap with the cowl.  I then folded the metal and compared to the original piece, I also test fitted it in the car.

To install this patch I used Fusor 108B, which is a high tech metal adhesive.  This is the same stuff as new cars are assembled with.  My body shop friend recommended this as it will seal completely around. The Fusor is expensive, about $50 a tube; however it is the best and recommend for new car auto body repair by all major car brands.  The 108B contains tiny glass beads which prevent you from clamping to tightly and squeezing all the adhesive out of the joint.  Very high tech stuff!

Following the Fusor instructions, I sanded the metal and made sure it was very clean.  I then applied a bead of the stuff all the way around the patch, I also applied some on the seams where I bent the metal together.  Then using sheet metal screws and a clamp, I held the patch in place until it dried.  I used the medium set stuff which takes longer to dry but allows more time to work with the part.  Once you press the pieces together, you can slide them around, but you are not supposed to separate them.  When applying the stuff, make sure your garage is ventilated  I’m not kidding this stuff stinks.  I would recommend that you set up the Fusor as the last thing, then go in for lunch, or the evening, as the smell will drive you out.

Once the Fusor had set up, I cut off the tops of the screws so that they would not be visible through the cowl vents on the top of the car.  Once that was complete, I coated the inside with  Eastwood’s Rubberized Rust Encapsulator Undercoating, which you cans in the photo all but made the patch disappear.

With all the repairs finished, I masked off the passenger area, and  gave the underside of the cowl a coating of the Rubberized Rust Encapsulator to stop any further surface rust.  This should also help cut down on the noise too, as the rubber will act as a sound deadener.