Chassis Surface Rust

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Jul 8, 2013
New South Wales, Australia
Hello everyone,

Just wondering what the best way to kill chassis rust is? I'm thinking wire brush, rust converter and then paint. Does this seem reasonable or will the rust come back in a couple of years unless I take off the body and sand blast the chassis and paint. How do I do inside the chassis rails?
This is on an Australian 1983 HJ47.

I don't want to have to take off the axles or cab. I just want to stop the rust now while its still surface. Mostly around the wheel/tyre area where stones have taken off the paint over many years. I realize this will happen again but I think any coating will chip off eventually. I just want to kill the rust that is there and seal it off to prevent it from getting worse.

Any suggestions gratefully received. I don't know much about painting and bodywork etc!
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I have the same problem with my 45 with light surface rust over the whole chassis. I blasted the chassis with a high pressure cleaner first to remove all the mud after 33 years of neglect. My plan is to clean and paint the outside with a rust converter and then poor fish oil inside the chassis rails every 6 months after a good clean. Mj old hj60 was getting rust in the gutters and roof turret so I used to give it a good dose of fish oil every 6 months and it stopped the rust for 10 years that I owned the truck.
Good Luck.
Fish oil inside the rails is good. A wire wheel on a sander or drill will help take off the outside surface rust. Painting over rust converter won't work. The paint won't stick. You have to put the converter on, let it sit then take it of with a wax/grease remover and clean the area for paint. It neutralizes the area killing rust so your safe. You should use an underbody sealer instead of paint. It's tougher and won't chip from rocks etc. Your local panel beater supplier can hook you up with an undercoat and appropriate spray gun for the sealer.
Painting over rust converter won't work. The paint won't stick.
Ok, so I put the rust converter on and allow it to sit for several hours to do its job. Would that be long enough or should I sit it for a couple of days?

Thanks for the heads-up on fish oil. Is there any particular type to use and method to apply it or do I just whack it on?

Also, just by the way, does anyone think those electronic rust prevention things work?

Thanks for everyone's help.
Sorry for the delay. A days wait is good enough. Get a wire wheel on a drill and sand the surface to remove loose rust and rust killer. Then sand it with a medium grit paper (80) to create a rough enough surface for the bog ( bondo) to stick and go from there. Any fish oil is good it's all the same.
OK, sounds fairly straight forwards!
OZCRUISER - Where did you get fish oil in decent quantities at reasonable prices in oz?
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Thanks for that. Do I just spray it on ( I'm a car detailer so I have access to sprayers that can cope with something thickish) or brush it on or what?
I would paint the chassis first as this stuff takes a couple months to dry. Once the chassis is painted you need to make a spray applicator that will spray 180 degrees inside the chassis rail. I made one from a old fire extinguisher by running a 4 ft length of rubber pipe with a heap of holes drilled around the end cap so it sprays 180. Don't take the truck on a beach until this stuff go's hard or the sand will stick to it like .... to a blanket. Once my truck is painted the chassis and inside of all panels will be flooded with fish oil to keep her on the road for many years. No one will want to steal your truck as it will smell like a fish market for a few months.
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Ok, thanks for the tip on the hose - I'll keep that in mind!

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