Rust Removal

MajorPayne
MajorPayne Posts: 100
edited August 2009 in Workshop
Heya DJ :)

Yeh I thought to do this before I started out, but I was wondering if I wold have to dip the whole frame or could I have dipped jut the part of the frame with rust on it, as I don't have a tank large enough to fit the whole frame in :)

That and I'm short of a battery charger.. Saying that I've got to buy a socket set today and get the rest of the running gear off my frame ;)

Thanks for the wicked topic DJ, in fact if I can get my hands on some of the kit and I get hassle with the frame I might dry doing this in the bath or something ;)

Kind regards,
MajorPayne

I'm a major payne in the rear an so's my saddle! Gotta love the local bike, innit!

The Phillips Phantom http://tinypic.com/a/x10g/2
The Raleigh ACE! http://i31.tinypic.com/25fhzcn.jpg

Comments

  • softlad
    softlad Posts: 3,513
    sounds like a lot of faff - easier to use a wire brush...
  • lae
    lae Posts: 555
    Yeah this works quite well, I have used it a few times for complicated classic car bits.

    Works even better if you connect up five or six anodes (nails) spaced equally around the frame.

    Do it in your shed with the door cracked open, or outside if the weather is nice. Don't do it in your living room with all the windows and doors shut as you'll either asphyxiate or the build up of hydrogen and oxygen will cause a potentially explosive atmosphere.

    Be careful if you are using stainless steel anodes though, as stainless steel has chromium in it which will make the solution pretty dangerous (don't drink it, give it to your dog or pour it down the drain). Don't use galvanised anodes for the same reason.

    I usually find that a lower current working over a longer timescale works the best, leave the frame for a day or so, then try it. Always disconnect the power before you move things about (touching the cathode and anode could cause a spark which could ignite the waste gasses - you DID do this in a well ventilated area didn't you?)

    Then you can scrub it with a wire brush if you need to, but usually just a plastic bristled brush and a good rinse will get the stuff off. Then I thoroughly clean the part with thinners, then slap some rust converter on the part to be absolutely sure there's no rust left (I use Jenolite which stinks of rotten eggs but works really well).

    Then you need to protect the frame, pretty much straight away. Degrease again with thinners, then apply a rust-proofing paint like red oxide primer (available at pretty much any halfords type place). After that you can put on any filler/bodystopper, normal primer, then paint and lacquer as normal.

    The reason you should put on red oxide first is because normal primer isn't actually waterproof. In fact, it's quite porous and sucks up moisture and will hold it against the metal, causing it to rust. If you're gonna paint your bike immediately with colour/lacquer then you can probably get away with not using red oxide, but if it gets scratched down to the primer then moisture will find its way in quite easily.

    A bit overkill perhaps, but like I said, this is my experience with classic cars which have much worse problems with rust than classic bikes! If you're going to take the time and effort to completely strip a frame to bare metal, it's worth spending just a couple of hours longer to protect it properly.

    This is my first post on this forum so I'm sorry if I've repeated things that other people have said before!
  • balthazar
    balthazar Posts: 1,565
    As the last poster noted, this is just the right sort of procedure for old car parts; I think there are good pictorials of it on instructables.com. However, any bike frame that rusty is probably not worth salvaging. The major prep work with bike frames is removal of old paint.
  • lae
    lae Posts: 555
    Yeah, on a really expensive classic bike with loads of surface rust, it's much better to do it properly than just to nitromors/wire brush it.

    I wouldn't bother on anything that I'm likely to own though! Even bikes with ornate lugs are simple enough to strip by hand...
  • pinno
    pinno Posts: 51,790
    Water washable Kurust, very easy to use. Much more environmentally friendly/ less dangerous then electrolysis.

    You can paint it on to the affected areas with ease with a small paintbrush. Turns the rust black and leaves a hard impeneterable surface on the rust which can be easily primed.
    seanoconn - gruagach craic!
  • lae
    lae Posts: 555
    In my experience with classic cars (which are much more rusty than classic bikes) those rust converters aren't perfect.

    They are fine on lightly rusted and fairly flat surfaces, but on heavily rusted or intricate areas (like lugs or around braze-ons on a bike frame) you still get clumps of rust where only the surface rust has been 'converted'. The only way to get a frame properly de-rusted is to do electrolysis on it, or spend hours with a tiny wire brush going round every little part by hand.

    Jenolite is by far the best of the rust converters though, Kurust is pretty average (as are all products by Hammerite).