Just replaced floors.. Now is the time to clean and seal up the under side of my XJ. I've seen por 15.. But a gallon is expensive! Any other products like it? How much do you think I'll need?

 

I used Chassis Saver (silver version with the loads of aluminum in my it) on my frame after I got stiffeners installed, and it is holding up great so far. I also painted my brake drums with it. Someday I intend on doing everything under the XJ in the stuff.

 

The NAPA branded POR-15 is DOM16 is similar and cheaper, it's held up pretty well on my axles for around a year now with a lot of gravel roads.

 

Use undercoating its what its designed for.

 

You need to be aware that POR15 (paint over rust) is a glorified rust stopper and is a primer, albeit a very shiny primer.

POR15 is meant to be painted-over after it sets up. It is not meant to be the finished product.

 

POR 15 IS JUNK just buy some good primer and paint

 

Great idea on a perfect surface, but this sounds like the underbody is far from perfect, just like most of our XJ's.

 

Apparently POR15 doesn't adhere well to clean surfaces, I did most of the underside of my XJ with POR ( I did almost wire wheel it to bare metal) , seems to be doing well, a few spots of rust. But that to be expected here as they use a crap ton of salt here.

 

There is a reason the Navy uses POR15 to seal their ships. The stuff is incredible and after using it on 2 other vehicles that constantly were beat with NY salt, I am sold.

Prep is everything with this product however.

 

the navy does NOT use por 15 on ships

 

you want something that is bad a$$ get some dupont (now AXALTA) LF-64025P CORLAR 2.1 MASTIC that will kick the $hit out of por 15 all day every day

 

https://www.ncpcoatings.com/products/naval.html this is what is used on navy ships

 

There's another product called Chassis Saver. It's what I've been using so far, and it seems to stick well. Just like any other type of paint...the prep work is everything. I've been painting over the chassis saver with some thick enamel brush-on paint from Walmart too. Can't hurt!

 

The Navy used it up to 5 years ago.

 

Doesn't POR15 need to be used in low sun light areas also?