How to remove heavy rust from exhaust?

[bitten_by_tarmac]

Hi.

I have a CG125, old but mechanically sound. Trying to pretty it up a little.

The exhaust has fairly bad rust. I don't want to spend a lot on a consumable part, but would like to make it less ugly. I estimate that 3/4 of the solid metal remains on the worst parts.

I bought a tin of high temp paint, but the can says I need to get to clean metal first. I attempted to do this with aluminium oxide paper, but it would take all week and I want to ride my bike. My next thought was to buy an angle grinder and suitable wheel, but am on a super low budget and can't really afford one.

So my options...

1: Take off the loose rust, paint it, hope for the best.
2: Buy an angle grinder, tell my stomach it is too big anyway, and needs no more pies and beer.
3: ??? Some bright idea from you guys...

I also read something about rust removal with heat. That seems dodgy, but will read more about it later.

 

[hillsy]

Angle grinders are cheap. No, really - they are like $20 here in Oz....probably $10 at HF or Lowes.

But we'd need pics to see what you have. If there's rust holes an angle grinder will just rip it apart.

A wire wheel on a drill will probably be softer, but again, if the pipe is rusted through it will probably disintegrate.

 

[bitten_by_tarmac]

Angle grinders are cheap, but I am poor.

$20 oz is £11 uk, if I could get one for that price I wouldn't have wasted my time typing this.

As far as I am aware the pipe is not rusted through. But the surface rust is too much to take off by hand.

I guess your recomendation is the grinder then?

EDIT: Cheapest I can get a grinder and wheel for, and still have the bike running for the weekend, is about £50, or $90 oz.

 

[hillsy]

I'd start with a wire wheel on a drill. If you already have a drill it's the cheaper option.

 

[bitten_by_tarmac]

So, you recommend mechanical abrasion, not chemicals?

EDIT: was looking at chemical methods, but they seem too slow.

 

[hillsy]

To remove the majority of the rust - yes. But a rust convertor would also be a good thing to use before you paint.

 

[bitten_by_tarmac]

OK, Thanks.

Unless somebody else has a great idea I guess I will be buying myself a grinder tomorrow.