respraying a rusty chainguard

[alecstilleyedye]

hi all, i've got an old steel chainguard that has rusted so badly that the paint flakes off. i want to respray it (never done it before), and am proposing the following:

1) remove paint
2) remove rust with wire wool and wd40
3) sand down
4) spray on primer
5) spray on paint

anyone got any further advice to offer?

 

[Smokin Joe]

1) Remove chainguard
2) Throw chainguard in skip
3) Sorted

 

[Chris S]

If you are using car spray-paints you'll need a top coat of lacquer to seal it. (modern paints are water based for envionmental reasons)

In my experience the paint often reacts and crinkles with what's on the surface.

You might be better off getting the chainguard powder coated (a whole bike frame is only £30) or just buying another one.

 

[alecstilleyedye]

1) Remove chainguard
2) Throw chainguard in skip
3) Sorted

it's a for a lady's bike for someone who doesn't want chain oil on her skirt, otherwise i suppose the advice is sound.

that said, none of my bikes had a chainguard to start with…

 

[chillyuk]

If it's old and rusty, wire brush loose rust off then give it a coat of Hammerite. Hides a multitude of sins and applied well doesn't look to bad.

 

[Strick]

Beat me to it, I was going to suggest Hammerite.
From what I understand, time spent on getting the prep right to paint on is where the end finish shows most results.

 

[alecstilleyedye]

i got some zinc primer and spray paint from a independent car spares place who were pretty helpful. i'll see how i get on, bearing in mind the advice about lacquer…

 

[Hacienda71]

Get a rust converter to brush on to the bare metal prior to priming.

 

[Mark Grant]

Rub it down with wet & dry using water with a little soap in it.

Remove as much of the rust as possible.

Wash and leave to dry then use a rust treatment as per instructions on the remaining rust.

De grease with some solvent then prime, topcoat and laquer, denibbing in between coats.

Best to paint it indoors but if you have to do it in the garage / shed keep the paint and guard indoors so that they are warm when you do paint.
Painting in cold damp conditions is likely to lead to the paint 'blooming', getting a milky white finish and spoiling the finish. If I have to spray little bits in my cold garage I help the drying along with a hot air gun. (gently!)

 

[Smokin Joe]

it's a for a lady's bike for someone who doesn't want chain oil on her skirt, otherwise i suppose the advice is sound.

She could wear a shorter skirt...

 

[battered]

Don't use WD40, you want it free from oil. Scrub it with wire wool/other abrasives until it's shiny, or if you aren't bothered about the finish too much then degrease it, get the rust off, 2 coats primer 2 coats gloss, from a brush. Nice thick paint film. Aerosols are bobbins. If you want a proper job, get it blasted and powdered, i's miles better than anything you can do DIY and costs loose change.

 

[Zoiders]

Take a scotchbrite pad in a drill to the rusty patches, that will have you down to bare clean metal quickly, clean it with spirit after to shift any left over rust/paint dust.

Then Hammerite smooth it with a brush, it's the easiest to do and it looks ok in comparison to the paint job on most roadsters - I have never seen a home aerosol job that looks good or stays put for long.

A lot of guards were stove enameled - not sprayed, so hammerite won't look that bad in comparison.

 

[battered]

There's a lot of truth in that. One thing I'd add is that contrary to the instructions Hammerite or SmoothRite IS best with a primer. I've seen it fall off car chassis parts, and that's a chore. I've never seen it fall off primed metal.

 

[fossyant]

For sanding - have you got a 'mouse' sander - dead handy, and makes light work of the rust. Remove as much as possible, then treat/prime and repaint - won't come back.