So I've got a little cancer in my driver side wheel well. I've stabbed all over it pretty hard with a screwdriver and couldn't get it to go through. Would it be recommended to cut out a new fender well section from a donor car or could I get away with sanding down to bare metal (after removing the strut tower and etc), filling in with something like quiksteel putty IF THE RUST IS NOT TOO DEEP, sanding down and painting? I've seen some pretty major repairs done to this area from searching but most everything I've seen has been Swiss cheesed metal, not caught (relatively) early like this.

If quiksteel is a stupid idea and a whole new fenderwell is overkill, what about sanding down the area to bare metal, painting, and welding a section over it?

Here is a picture of the rust:

 

Start by cleaning the area with a wire wheel. Only then can you judge what to do with it.
It might be lightly pitted, and only require a total removal of the rust, then epoxy primer, a bit of body filler, primer and paint.

 

I had to cut out most of the thinner body metal of the wheel well to get to the rust, it was mostly done for anyway. This is sanded down to surface rust only. Some products I have seen for rust treatment recommend leaving surface rust for whatever chemical processes they use to be most efficient (including POR-15 which is what I plan on using). The thicker metal of the strut pillar cap that is tack welded to the body metal is mostly sound, I only found one pinhole that compromised the surface. The rest is pitted. Regardless, I think I have made up my mind that a donor piece from another car is in order and what I will be doing this weekend will be a temporary fix to keep it from getting worse while I find a donor piece.

I'd still like opinions though, so here is my progress thus far:

Edit: I could only take a pic from one angle but I did peel back the outermost edge of the metal to get to the rust inside there as well. It has only spread at most 1/4" to the inside of the metal you can see in the photo. I can see all of it by sticking my head up in the wheel well and was able to get all of it as well.

 

soul.justice you're trying to embed the imgur link, not the actual image link.

 

Probably explains why I couldn't open it on my phone. It's been a while since I've been on the forum, I don't remember how to do half the things I should

edit: fixed post so everyone can see the pictures