If you want to slow it down until you have it cut out and replaced, get some Ospho. Follow the directions and it will kill the rust if you can get the product to it.

 

Yes, but waay better than POR15 (which uses the suffocation method to stop rust)

Everyone else, this is a thread-necro!! OP has long since never been back


For rust in cavities, you won't find better than Bilt Hamber Dynax S50. Comes with a 360deg lance to get it up in there, it will prevent rust as well as actively kill what's already there, which a lot of other products don't.

You can get it from clean-garage.com in the USA, comes in a ~26floz spray can.
https://clean-garage.com/bilt-hamber...corrosion-wax/

 

I ordered 2 cans based on your recommendation. I have a lifted Jeep WJ as a third vehicle, and I feel like I'm losing the rust battle... Figured I'd give this a shot.

 

Good deal, be sure to follow the instructions, you can get them on the bilthamber.com site under the product info.

 

Ok thanks. I’ll check it out!