We ground the chassis to bare metal today and painted it with rustoleum. Rust was only paint deep and not really bad yet. No flaky rust on the joints.
The front end is rust free. I removed the trailer harness. Probably the 1st owner tow a boat and let the back end of this rover get into salt water.

 

Wow! That looks amazing!
What did you grind with?
BTW I grew up (some would argue) in Nutley.

 

Looks great. I'd hit it with a few passes of undercoating to seal-in the base coat.

 

Looks great. For extra protection I'd hit it with a few passes of undercoating to seal-in the base coat.

I see you took the extra time to hit the axle. Looks great!

 

Nice now spray some waxoyl on the inside or used oil because that's where they are most vulnerable

 

Quick run to Harbor Freight and got a $14.00 Grinder. 2 pieces of wire grinding wheels for $4.00 a piece. Used our old faithful dremel for hard to reach spots. My original Idea was to get a sand blaster but the total with compressor and sandblasting powder was close to $450.00. Plus the breather mask and the flying dust all over.
Nutley? We could have been neighbors still and do projects together. Hehe

 

Its quite easy and fast. I do this to the other every 2 years. But still got rusted. My other truck has flaky rust. Have not examine thoroughly yet but here is my sketch of my plan from a 1/4 steel plate to add beef.



Here is my plan if the other frame is rusted bad.

 

Thanks! I have seen waxoyl in much of the rustproofing LR shops. But I'll take the chance to completely seal it after I spray a rust converter inside.
My other plan is to spray an expanding foam that you use for insulation inside and maybe completely seal the inner frame. Im thinking that if no water gets in then rust wont develop, plus it will prolong the accumulation of rust with lack of air in the cavity. This is the best time to do it than summer. Its not so humid at this time.

 

The problem with the rear frame on a a disco is that at each corner on the inside there is a small piece of angle iron spot welded and an overlap top and bottom which trap water and cause rust there is no way to seal it and rust converter will not work, and spray foam will only trap more water and exacerbate the situation, a proper application of waxoyl or used oil will seep into the seams and stop rust.

 

Wow that looks sharp! I am planning on doing the same to my Disco this summer.

Nice Job!