Undercoating stripped/restore?

[SD-KC]

Hey all,
At some point in my cars life, I'm guessing it was leaking brake fluid. That leak is no longer happening but it caused the frame undercoating beneath the reservoir to fail and now it's flaking off. I have a section of front frame rail where there is no undercoating and is bare metal. Due to this, I don't drive the car in the rain and have been considering how to protect this area. The metal is solid with a coating of surface rust. I spray some fluid film on it to give it something or maybe just make me feel better about it.
The length of missing undercoating is maybe 6-10 inches wrapping under and on top of the rail. It has flaked off right to the bracket where the fuel lines are mounted. I am thinking of using the three step POR15 product to repair this.

Any thoughts on whether this plan is sound? Any other ideas?

Thanks

.

[15Michaeljoseph]

I'm sure POR would be alright, but there are cheaper ways to fix it just as well especially considering there's just some surface rust in the area. First thing is you want to clean any remaining brake fluid residue (and your fluid film) off with acetone or a pre-painting prep spray. Clean it REALLY good. I don't know what it is about brake fluid but I had to do a similar repair on my car and the area where the brake fluid had been took a ton of cleaning to get paint to stick. Then use an abrasive like a wire wheel to roughen up the area and remove as much of the rust as you can. Clean with acetone again. At this point, I would use a product like Eastwood's Rust encapsulator (I've used their products on some serious body work/ rust repair on my car and I think it's great). It's much cheaper than POR, and is supposed to neutralize any remaining rust. Unlike POR, it also sticks to bare metal. This is the main reason I don't really like POR. I'd do two coats of encapsulator, then once it's fully cured, spray with some rubberized undercoating. Eastwood's makes one of those as well, that's a great product... But on my last project I actually ended up trying the Iron Armor rubberized undercoating from Harbor Freight and was pleasantly surprised that it sprayed well and seemed to cure well also. After this, you should be done. If you want to be really OCD (like me), after the undercoating has dried fully, hit the whole area with some rust preventative wax spray. Sent from my moto g(6) using Tapatalk

[Sunnyledge]

Another option is to remove the rust. I’ve had good results with a non-acid rust remover (Metal Rescue) gel. Remove superficial rust with light sanding or wire brushing. Apply the Metal Rescue and cover with plastic wrap. After 12-24 hours wire brush, rinse and repeat. It may take several applications, but you can get to bare metal. Then epoxy prime, paint and under coat or apply cosmoline. Most rust encapsulators will fail as will POR-15.

[calster]

Chassis Saver is a good product and easier to apply since it requires a one-step process.