It would be best to use the factory-style clip if possible. Fender To Rocker Panel Bolt/Nut 1965-1970

 

 

Probably needs to take the bolt out and see if the fender and or the body side mount is still structural. If so easy fix. If not, you can weld it but watch your heat with nice paint. Trick is spot welds and cool each weld with air nozzle. Obviously easier to remove the fender if ya got rust issues

 

This looks like a good option. Thank you!

 

I don’t think you will get a good long lasting weld if you weld in place, looks like rust.
I would suggest removing the fender then make a plate to span across to solid metal, grind the back side down to bare metal and weld from there.
Short welds to control heat. Don’t forget to tape your door and fender to prevent paint chipping.
Its not the easy way but you don’t want to do it again.

 

I don’t think you will get a good long lasting weld if you weld in place, looks like rust.
I would suggest removing the fender then make a plate to span across to solid metal, grind the back side down to bare metal and weld from there.
Short welds to control heat. Don’t forget to tape your door and fender to prevent paint chipping.
Its not the easy way but you don’t want to do it again.

thanks! I’ve ordered the part and will put it on next week.

 

Its not the bolt, its the bracket on the fender is broken, and allowing the fender to drop.

 

THAT NUT ALWAYS BREAKS , I weld them in .

 

 

okay so yours broke Fender part .
remove fender and bring it to a TIG welder . have him weld in a new plate and drill the hole . with the TIG he can use little heat and not screw up the body work/paint.
I would still mig weld the nut in place on the body .

 

The fender in the last picture belongs to
1stGenMustang_6_5
the guy asking the question, thats why I said its not a bolt problem. My fender is the first picture I posted, as an example of how it should look.

 

There's a patch panel for that area, but it looks like a poor one. Patch Panel Fender Support Brace Passenger Side Mustang 1965-1966 There's supposed to be some adjustability to the bottom of the fender.

 

There's a patch panel for that area, but it looks like a poor one. Patch Panel Fender Support Brace Passenger Side Mustang 1965-1966

That brace is a starting point to replace a serious rust problem, but it doesn't seem like that is the problem in this case. This is a midwest fender with serious rust.

And a clean California fender.

So the problem area is on that brace, but its not a difficult repair, it
just cracked and then broke.

 

Thats a different problem, I'll try to find some pictures that show it better.

 

I am not sure of the actal configuration, but since you have nice paint.. I would consider using panel adhesive to attach a replacement bolt. You need to abrade the pieces being epoxied together with 80 grit and wipe down with acetone prior but that should not be much of an issue with a Dremel.

https://www.3m.com/3M/en_US/collision-repair-us/featured-products/structural-adhesives/

 

I had a similar issue. I went the panel adhesive route using a steel washer. When I got the car the PO had welded the fender to the rocker panel to hold it in place.