so I was poking around under the dash and now i'm not happy. I need to patch my cowl on the driver and passenger corners. this is going to be a fun repair . going to be an awkward spot to cut and weld. this sucks because my cab is actually real solid except for this area. rotting leaves in the cowl was the cause.

driver


pass

 

No doubt, the best way to solve the problem is to cut out the rusted area, form new metal to shape or cut replacement sections out of an unrusted donor cab. However, you may not be able to take the truck out of daily use long enough to do a good teardown like it's going to need for that. A short-term stop-gap measure might be in order.

First, stop the rust. Thoroughly clean the rusted area, gaining access to all the affected rusted metal. Then apply liberal quantities of a rust-converter such as Ospho (Ospho Rust Treatment - Since 1947) all over the area and surrounding metal from both sides. This can be messy, so wear face protection and a respirator. Inspect and reapply until you see that all the cleaned but rusted metal has been turned black by the rust converter. Then apply a good rust-inhibiting primer.

Second, to seal the cowl area, use either a good gutter flashing caulk or NP1 elastomeric sealant (https://www.master-builders-solution...asterseal/2001). After curing, paint to suit.

This is not intended to be a permanent fix, although it can be a long-term fix, rather to stop the rust and seal up the affected area. It is a quality stopgap measure to get you by until you have time, money, and equipment to do a complete tear down, cut-out, weld-in, and proper paint. Needless to say, whatever you can do to abate the conditions that caused debris accumulation in the first place would be helpful in preventing future problems. A garage in which to park your bumpside baby comes to mind. I'm advocating on her behalf, here

Good luck!

 

I feel your pain. I'm in a similar situation. Lots of measuring cutting and welding.

 

luckily after I dug out the seam sealer the rot is confined to just those two spots. i'm seriously considering shaving the cowl vents, i'll be running an aftermarket ac system so I won't need the fresh air intake.

 

2X Phosphoric Acid treatment.

I had luck back in the day, with fiberglass patches on top of the treatment described above. Use polyester, not epoxy fiberglass resin for the metal contact. Polyester resin is sticky and flexible. Epoxy can go on top if you wish (Gel Coat).

Make a mylar film pattern of the area, with creases if needed. Apply glass cloth, resin with hardener just enough to saturate, and apply. Push on it with scrap foam, support the foam with sticks. Let completely harden.