Thank you S14rebuild for the comment, I appreciate all comments!!
As for dluevanos01 "This is good. I plan to do the same to mine in a couple of weeks. What did you use to remove the undercoating? "
I literally used a angle grinder with a wire wheel but it takes forever!! I didn't know there was a better option until I discovered this . You want to be using a Poly Strip Wheel Disc Clean Tool Removal Rust/Paint, Example :
So this particular type of pad, they come in different style for like angle grinders, or 2-3" pads for die grinders. It's a bit more expensive but they fucking remove that undercoating, paint and rust off so quick, it's not even funny.
Anyhow , I plan on building a grip monster. So I got some Ulterior motive metal fender flares waiting to be put on for some time. After getting the rust repair out of the way, I went ahead and started welding on some Ulterior Motive Fender Flares. Since I was able to remove all the paint around the welding surface, I choose to weld it with Tig because it will allow me to properly have the fusion that I need without excess metal build up which will have to get grinded down. You can totally weld this with a 110V Mig welder but I choose to go with the Tig welder. The Tig welder I have is a Everlast 255 EXT. It has all the fancy option for exotic metal etc for 1/3 the price of a Miller Brand with 5 Years Warranty. At the end of the day, it will require some body filler because this much welding on thin material, it will expand and contract which results in distortion, that the nature of welding. The location of where these fender flares sit, will be the same height as the oem. Here is a quick video of the process.
After poking around, I noticed some surface rust on the passenger side rear wheel well. It was around where two panels meet. I noticed that a lot of rust starts where two panels meet, or where there is some old ass crusty 27 Years old seam sealer, or frame rails that been getting rubbed up on speed bumps. Anyhow, I found that the best way to deal with this rust that was on the passenger rear wheel well, was to cut where that black line is and drill out all the spot welds. That way I can go in there, remove all the rust , sand blast the pieces that I was able to take out, then treat all rusted area and the pieces that I took out with Eastwood Fast etch, then prime it with Eastwood weld thru primer. Weld it back into the original spot and then later on coat it with Eastwood Platinum Rust Encapsulator. At this stage in the project, no rust can escape. I'm the RUST HUNTER
Also, there was a opening here, not exactly sure what used to be here but it was letting water into that area, so I just cut that piece out and welded a plate here.
I appreciate that fellow 240sx members are viewing this thread. I learn a lot from other people who share their experience and I want to contribute my experience and whatever knowledge I have whether it's right or wrong. Let me know if I'm doing something wrong so I can fix it! Thank you.