I found this after removing the left front fender but what's behind it worries me. I see some rust in there and I'm thinkin I should just spray some por 15 in there and cap the hole. Anybody ever encounter this? Any suggestions? Thanks!

 

Cut out the rust, weld in new metal.

 

I would cut it out like puma 1552 suggested. sand down any surface rust you find. The problem with "Sealing" rust out is that if at any time water seeps in it will be even worse.

 

I agree, weld in new metal if its possible. If, for some reason, you can't, POR 15 will likely do the job, for now. I have used it myself, and, other than its UV issues, its pretty good, and it does have some structural integrity, however, in this case, its just a better band-aid. But it will seal the rusted metal and it will be impermeable to any additional moisture. Biggest issue I see is that rust *looks* like it came from the inside out, which means its possible there is a whole world of hurt behind it. Or it could be just some rust creeping under the sealant and its no big deal. Hard to tell, the picture is small. You really need to investigate and figure out if there is a bigger problem going on.

 

Yeah, it does look like water is collecting inside the kick panel area.

 

The other side was like this as well and I cut out the exterior damage and welded in new metal. Sorry about the small pic but it was with my iphone since I'm having PC issues. I looked inside the hole and I can see surface rust in the kick panel but I can't figure out how moisture is getting there from the inside out. This is the only problematic rust I've found on this car besides the rear impact bar so I want to stay on top of it

 

I would be looking at a leaky windshield as the culprit, but could also be t-tops if you have them. The car I've been working on has a leaky windshield and its letting water in which is rotting out the kick panels and rockers. Your issue looks similar.

 

Have (had) holes there myself on both sides, from what I remember this is another moisture trapping foam area like the a-pillars...

Best bet, cut it out and weld in a new piece of the same gauge, not hard to do (did it on the weekend).

 

I am dealing with this myself. My cowl drain rusted out and eat through the firewall too. I think the floor of the drain went first, then water leaked down the inside of the paneling, like yours. I have not pulled the fender yet, but looking through a whole underneath I saw similar damage. You need to find out the source of the problem, as well as fixing the damage...

 

Found the culprit!.....I picked out all of the seam sealer
In this area and found a HUGE gap between
The seams and right near the rust..
It appears as though water was getting past
The sealer and into the rocker cavity.....I'll post the pic soon