Best internal frame anti rust coating?

[512tr]

Are there any long-term tests of  internal frame coatings?

I have started a full restoration of my 87 MJ and have done some rust repairs. My findings are that all rust attacks on the frame/unibody are coming from the inside, the area around the front leaf spring brackets were the worst. The left side cab corner was gone, and some minor rust in the cabin floor.

 

 

[fiatslug87]

I’ve heard good things about Woolwax, they make several products.

[jeff351]

I'm a big fan of Eastwoods.

 

https://www.eastwood.com/paints/rust-solutions/rust-treatment-removal-products-how-to.html

[75sv1]

I am planning to try and have one of my XJs done by a Linex dealer. I think its $500 or so. 

[512tr]

Thanks for the replies, did use Eastwood Internal frame coating in the frame behind the cabin. Will consider using either Woolwax or some linseed oil based coating in the unibody frame below cab.

 

 

[Elwiscon]

My underside wasn’t rusted, but I removed the bed and other components, removed the light surface rust and factory undercoating,  sprayed it with Raptorliner and etch primer to protect it from rust, I sprayed the axle and other components with Duplicolor chassis paint . I will be using POR15 and raptorliner for the front once i replace the rusted out passenger floor pan. For the interior of the uniframe I will be using the Eastwood spray paint that comes with a tube, I used it on my LJ wrangler and it still looks good after 3 years. I used Eastwood, raptorliner and Duplicolor Chassis paint on the LJ, I have driven it off road, mud and snow and it looks good, I usually pressure wash it after driving it on mag chloride during the winter, I try not to drive on it though. 

[gogmorgo]

Wax or oil based products are best. Things that get reapplied every year. 
Rubberised or tarry substances (like bed liners) will just trap moisture against the metal when it does get in. It’ll rust out and you won’t notice it’s happening. At least paints have the decency of flaking off when they fail on you.