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NSW government quietly changes loading zone rules

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5 Replies
By DavidBurrell – 25 January 2022
  • What is the best way to treat surface rust on sub frame under car

  • Judgefatboy

    JA079

    10 years ago Quote Reply
    any paint store will sell you what you need i believe its called derrena you just need to give it a really good clean with wax & grease remover before painting to get rid of the derrena residue
  • Judgefatboy

    madmuz

    10 years ago Quote Reply
    Depends how bad it is? If it is just surface, get onto it with a wire brush in a drill or a flap wheel in an angle grinder, get as much off as you can. If it is holes, you have to cut away thin metal, kill the rust with one of the brush on or spray on rust killers, then plate over the holes, then use more rust killer, let it dry, sand, etch prime or cold gal.... then finish off with one of the underbody coatings. Any time you have any opening into the frame, try to get as much dirt or rust out by poking in wire, bent s**** drivers etc, use a vacuum cleaner, if it is a smallish hole, use a piece of garden hose in the end of the vacuum tube with a rag to seal around, to get in small places. Soray rust killer inside once clean, and maybe spray in some cavity wax.... then do the plating up. Look for where water might be getting into the frame to start with and block that off with foam, silicon, bog or whatever.... wherever water can get in, it can feed rust or cause more....
  • Judgefatboy

    madmuz

    10 years ago Quote Reply
    Woops, just re read your post, surface rust, get rid of what you can with flap wheel or wire wheel,, kill the rust, spray over with underbody or sound deadner/stone chip or the like.
  • Judgefatboy

    Aether

    10 years ago Quote Reply
    As madmuz said, but one extra step in the middle.

    After you remove the rust with a wire wheel or similar mechanical method, treat the rust you cant clear off and then make sure you paint the area with a specialist product like an epoxy primer or rust preventing paint. This is to deprive the area of oxygen and prevent it coming back. Then cover it with stone chip product/sound deadener. The deadner itself is not rust preventative. You need to do the paint first.
  • Judgefatboy

    madmuz

    10 years ago Quote Reply
    Hi Aether, yes correct, that is actually what I meant by "kill the rust with one of the brush on or spray on rust killers" I usually use one of the rust converters from the Bunnings panel beating isle. Removing dirt and debris from inside the rail, filling it with some sort of cavety wax or rust killer, then stopping water from getting into the rail again is key, then as you say Aether, preventing oxygen from getting at the metal on the outside, imo.
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