The car is a 2004 Infiniti G35 Coupe and rust is occurring on the rear fender wheel arches and am looking for advice on how to tackle this problem, I spent months searching and have these ideas. Hopefully I can do this without welding and cutting (shops are quoting me around $4K+ they want whole new rear quarter panels)

The Rust
https://imgur.com/gallery/pLYZT6t

I am not looking for absolute perfection and would like to give it a try myself without having to weld in a piece

I also purchased a pair of NISMO Fiberglass (FRP) fender flares (more like a lip) that will go over the arches. Here is what they look like
https://rocketz.net/wp-content/uploads/2016/06/F-N350N2_6.jpg
http://i1000.photobucket.com/albums/af129/AdvanZ33/009343fe.jpg



Option 1
Sanding and stripping the rust/paint in that area down to the bare metal and filling the area with body filler (Bondo) Essentially I am following ChrisFix YouTube Video https://youtu.be/n4vusY2-rkQ

Option 2
Sanding down as much rust as possible in those areas, and using either POR-15, Eastwood or the "Bill Hirsch Miracle Paint" I was siding more with the POR-15 as they also have a Fiberglass Power Mesh and an Epoxy Putty

I have heard great stuff about POR-15. However, I have also heard the opposite, in that you must follow the directions absolute and even the slightest thing wrong in the prep ruins the whole repair.

Option 3
Sand everything down to the bear metal, and ground out the really rusted pieces, and if possible Order a patch panel and find a shop that can mold and weld it in + paint. Not sure if this is doable, I have tried searching to see if anyone done this but google is tricky.

Ideally I would much rather do this. I just wanna know if that is possible and what would I need to do.

Not quite sure which method to use, so if anyone has any recommendations or advice it's much appreciated. Thank You!

I glue all my patch panels, I don't weld.
The panel adhesives available at the paint stores are
more than strong enough, and lasts.
They are expensive, I hold the panels in place with
sheet metal screws and remove them once the glue sets.
I fill the screw holes with more adhesive.
You can put a flange all around the patch panel
with a cheap tool like this.
https://www.harborfreight.com/air-punch ... p0EALw_wcB

Option one : Hack work.

Option two : Not much better than the 1st.

Option 3 is Best
Option 3 can be done with Adhesives and with fillers and with quality paints.
You can do option 3 your self but will require some tools and equipment STUDY!.

The trouble with Rust is its always deeper than it looks and to repair it it all has to be removed. either by cutting it out and removing it or by Blasting or Chemically.
Chemically is not the best and Prone to many failures. If you don't get ALL the rust out it WILL come back! in a very short time frame.

There is nothing wrong with an adhesive repair when done correctly.

Doright wrote:Option one : Hack work.

Option two : Not much better than the 1st.

Option 3 is Best
Option 3 can be done with Adhesives and with fillers and with quality paints.
You can do option 3 your self but will require some tools and equipment STUDY!.

The trouble with Rust is its always deeper than it looks and to repair it it all has to be removed. either by cutting it out and removing it or by Blasting or Chemically.
Chemically is not the best and Prone to many failures. If you don't get ALL the rust out it WILL come back! in a very short time frame.

There is nothing wrong with an adhesive repair when done correctly.

I think I’m going to order the front fenders as they’re pretty cheap for the pair and use those as my patch panel, they’re the same size I’m pretty sure

Here are images of the front / rear fenders
FRONT FENDERS




REAR




SIDE VIEW

update I just picked up a new pair of steel fenders $200

I dont see anything wrong with the fenders you have?

Cheap aftermarket fenders dont fit as well as original OEM stuff.

The little bit of rust in the rear is easily corrected your over thinking this I think.

I have done several por15 repairs on rust like you have there. If the rust have not eaten any holes would clean everything, paint with por15, filler, 2k, paint and clear.

You must get all the rust out otherwise it will just come back.

Por 15 is designed to be used OVER Rust you just wire wheel it a little and apply it.
POR15 is a POOR product in my opinion. But it has its place in the industry I suppose.

If you remove all the rust its done its clean metal apply EPOXY and be done.
The Key here is being sure you removed all the rust and your sure its all gone, Blasting is only sure way and even then I cold Galvanize the metal and paint over that.

Here is how the replacement front fenders look when next to the rear

album link
https://imgur.com/gallery/9qFznWO