Okay, I pulled the fenders of my Fastback in preperation for media blasting and found the cowl vent area to be solid as new with absolutely no rust. The problem I have is that I stuck my bore scope through the cowl grill and in the drain holes on the ends of the cowl to get a better look under the ends and while I didn't find anything starting to rust, I did notice that it looks like crap under there with flaking paint and such. So, what do I do now? Ford, in their infinate wisdom, made the 67's with the cowl panel welded to the body so removing it is a major undertaking. Am I stuck with doing it anyway or is there a better way to get at that area? Since I am going to the trouble with a ground up rebuild, I don't feel right leaving it this way even though it can't be easily seen. I also don't want to have any future problems because I didn't address it.

 

Ford's wisdom included using the cowl as a torque box to join the left and right side of the car for structural strength. If they had just screwed it together for decoration, it would be a lot weaker. Trash and crud tends to collect over time. Remember, the average life of a car in the mid 60s was 4-5 years. I doubt there is paint flaking under there- That area was unpainted. You need to use a combination of stiff brushes and air guns to remove as much of that crud as possible. Once cleaned up, you could block the drain and partially fill the area with rust inhibitor, or insert a special hose used for this purpose.

 

Never thought of the structural strength thing. What's special about the hose and where would I get one? REALLY don't want to take the cowl panel off if I don't have to.

 

...citations?

 

A Ford engineer, who was involved in designing the car. I once asked him why he didn't galvanize the bottom, instead of just the top. The top was galvanized to keep from getting rusty (ugly) along the edges of the vent slots, but they figured there was no way it would rot out the bottom of the cowl in 5 years, even if it was bare steel (which it was!). They probably saved $1 per car that way, which by 1966 was over $1,000,000. Back then, the warranty was 12 months/12k miles, whichever came first, except cars equipped with the 289 High Performance engine, then it was 3 months/3k miles. 5-year old cars were junkers being bought by high school kids. I was one of them, my first 66 Mustang was 5 years old, and it cost me $200 (it needed a tune up).

We have a different perspective today, a 100,000 mile warranty is the norm. Typical shock absorbers, for example, barely made it to the end of the 12 month warranty, while exhaust systems didn't last much more than that. My 12-year-old Explorer has the original exhaust on it, at nearly 150,000 miles. In the 60's, a 100,000 mile car was considered junk, and if you told them you had an exhaust system that old, they'd have figured you were making it up.

 

What I did on my Falcons (same cowl design) was to get as much stuff out of there as possible. Then I partially blocked the drain and filled the area with POR-15. In my opinion POR-15 is much better than any rust inhibitor as it is basically an epoxy paint that uses moisture and/or rust as the catalyst for the epoxy. If you have the unibody on a rotisserie it would be much easier to get the entire area coated including the underside of the cowl. Very tedious operation. You can also use a small sponge to reach up through the air vents to be sure to get the area around the vents well covered. Be sure to wear rubber gloves as it won't come off of your skin!

I have repaired cowl areas that have rusted through by reaching up through the vents with POR-15 after taping the underside with masking tape. After several coats on top add a layer of the POR-15 mesh they sell on the underside. One such repair was 10 years ago and it is still holding.

POR-15 could be the greatest product you could ever get acquainted with, especially on a '67 where they changed the seam sealer they used. Every '67 I've seen has seam sealer peeling up. Coating the seams with POR-15 before applying new seam sealer will cause you to never have to mess with it again. Same for floorboards. Couple of coats of POR-15 on the floorboards (bare metal) and never have another rusting issue again. Also coating the weatherstrip channels and the inside of the doors and quarters is recommended.

 

The hose used for rustproofing can be bought from 3M, and other sources. Very popular with Zeibart, for example.