Hey everybody.

I removed my cowl today to take care to some surface rust and I ran into a problem. On the inside there is a grey primer and there was rust was in some areas popping through it. I would like to coat down there with POR15 and i really don't trust leaving the rest of the primer there seeing how there could be more rust underneath. Has anyone ever removed the primer down there and if so how did you guys do it? I could barely maneuver enough to sand down the rusted areas.

Thanks

You may want to consider buying a new or used cowl. That's what I did. The thing that causes rust underneath those panels are the rubber plates underneath that end up trapping moister. I'd look for a cowl that is rust free or has been treated.

Looks like a terminology issue here. The cowl is generally thought of as the removable flat metal grill between the hood and windshield. Below it is the plenum area for the wiper motor and mechanism, cowl/plenum drains, and air inlet for the heater system. If I read the original note correctly, it is the plenum area that has some rust, much of which is very hard to get at (agreed!!!).

One way to get to the rust is with a long rod tool with the end wrapped in sandpaper, emory cloth, or similar. Mount the rod in a drill motor to reach tough spots. Other long, skinny tools of your design may get to other spots and crevices. After that, a thorough cleaning with POR-15 Marine Clean (or other degreaser) followed by POR-15 Metal Ready (or similar) to kill the rust. Follow with primer and paint of your choice. Short of destroying the firewall and plenum area, it is almost impossible to reach all the small areas with any kind of tools.

Hope this helps.

Jim

I did the same thing to my car though my rust was trivial.

https://sites.google.com/a/thecomputerrehab.com/260z/body/cowl

Ditto to Jim's response.

Thanks Jim, Yes I was referring to the Plenum area and your reply was very helpful. Today I tackle the beast and start getting into the finicky areas 8)

thanks-

Sam

Another option - in many area's there are people that run "Portable Soda Blasting" businesses. They will come to your house and you can have them soda blast that area. The soda can then be washed out with water.

After that - you can use something like OSPHO - sprayed on with a hand pump bottle - let it sit/work for 12 hours or more - then apply POR-15 or prime and paint.

FWIW,

Carl B.