Any reason we shouldn't patch the cowl w/glass?

[electricgreen]

Ok, so we have a hole in the cowl on our 73. It will likely see rain at some point. Is there a really good reason we shouldn't patch it with fiberglass? since they don't make a repop replacement piece, it would be hard to find a metal replacement. It's near the heater core, and we could actually reach it now with the dash in because we have the core & glove box out. We'd rustmort the metal after cleaning it up, then coat it with something like POR 15 (eastwood's version). Thoughts? Any reason why this would be a bad idea? 'Glass is waterproof, doesn't rust and is easier to get into this spot-plus is way more available that a replacement metal piece so it seems like the way to go...

 

[latamud]

I taped a piece of cardboard under the dash, had the cowl panel cut off from the top(grill piece) on my 66, then I layed two layers of fiberglass matt over the cardboard and overlapped onto the metal. No more leaks. Bad thing, no fresh air but I don't care, it doesn't leak. And, I can always cut holes and mold in some hats later.

 

[t_chelle16]

I recently patched mine with fiberglass. I don't know how well it will hold up long term, but it was quick & easy and has stopped the leak for now. And if it ever does rust or start leaking again, then I'll tear apart the front end and actually replace the panel.

Incidently, if it's just the collar that's rusted, you can get plastic replacements for those.

-Chelle

 

[Platonic Solid]

Ok, so we have a hole in the cowl on our 73. It will likely see rain at some point. Is there a really good reason we shouldn't patch it with fiberglass? since they don't make a repop replacement piece, it would be hard to find a metal replacement. It's near the heater core, and we could actually reach it now with the dash in because we have the core & glove box out. We'd rustmort the metal after cleaning it up, then coat it with something like POR 15 (eastwood's version). Thoughts? Any reason why this would be a bad idea? 'Glass is waterproof, doesn't rust and is easier to get into this spot-plus is way more available that a replacement metal piece so it seems like the way to go...

I think you know the answer already, but don't want to hear it. The hole is probably in an area that's impossible to get to from the outside vents. Thus you're going to have a very difficult time properly applying rust treatment there. Though fiberglass will fix the immediate problem, the best long term solution is to go through the painstaking process of drilling the cowl cover off, thoroughly addressing all the hidden cowl rust issues, and welding hand frabricated metal patches in as needed. If you patch it with fiberglass now, and you later get more rust through holes, you'll have to deal with the additional PIA of fiberglass removal to do a proper weld repair.