Best rust remover is...

spock500

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Could it be vinegar?

This heavily corroded brake pipe bracket was half soaked for a few days while I waited for the MB parts to arrive.

There's still a few clumps on there, but the part that has been cleaned is back to bare metal.

Lightly scrubbed with a tooth brush after maybe 3/4 days soaking.

Rust1.jpg


Left for 24 hours (indoors) how quickly does that oxidise again.

IMG_0443.jpg
 

hotrodder

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If you're not in a hurry then yep, vinegar (acetic acid) or molasses or citric acid or oxalic acid all of which work by chelation. Phosphoric acid is another (typically the active ingredient in commercial rust removers/converters although a few are citric based i think) which leaves a phosphate coating behind which helps prevent flash rusting. Vinegar obviously has the advantage of being commonly 'to hand'. Personally i hate the smell of vinegar and buy citric acid- dirt cheap by the kg from ebay/homebrewing supplies etc compared to the local chemist/supermarket. Citric also cleans and passivates stainless and cleans/brightens ally, hot solution works better/quicker than cold
 
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spock500

spock500

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If you're not in a hurry then yep, vinegar (acetic acid) or molasses or citric acid or oxalic acid all of which work by chelation. Phosphoric acid is another (typically the active ingredient in commercial rust removers/converters although a few are citric based i think) which leaves a phosphate coating behind which helps prevent flash rusting. Vinegar obviously has the advantage of being commonly 'to hand'. Personally i hate the smell of vinegar and buy citric acid- dirt cheap by the kg from ebay/homebrewing supplies etc compared to the local chemist/supermarket. Citric also cleans and passivates stainless and cleans/brightens ally, hot solution works better/quicker than cold

Thanks for that.

I will give the citric a try, when you say 'hot solution' what sort of temps, 40/50c?

Would heating vinegar work also?

Cheers,
 

hotrodder

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When passivating stainless with citric temps can be as high as 60-70ish C which about halves the time compared to 40-50C. When i'm mixing some (~10% by weight) i just use hot water, typically i'm working with stainless or ally (i'm a fabricator & welder) rather than heavily corroded bits of mild steel though, thinking about it probably need a heated tank to maintain the temp for long enough to make a significant difference in time for something like that brake pipe bracket. Dunno how heat will affect things with vinegar or if there'd be a significant difference in speed between citric, vinegar, molasses or oxalic

FWIW part # a0009891025 is an MB cooling system flushing agent which is... citric acid powder (although those jokers want a tenner + VAT)
 
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spock500

spock500

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That's good to know.

The reason I ask, is that we have a water purifier which takes an age to de-scale using vinegar. It's stainless steel with lots of inaccessible tubes so conversational de-scalers not really an option.

I will order some citric and give that a go, cheers.
 

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I have always bought the 30% and that cleans any chalk out of anything, its what they use to clean stonework on houses, perfect for cooking Salmon too, just pop some 15% (dilute with water) into a plastic bag with the salmon inside and its ready in a couple of days
perfect for moss on driveways and nature friendly
 
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spock500

spock500

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I have always bought the 30% and that cleans any chalk out of anything, its what they use to clean stonework on houses, perfect for cooking Salmon too, just pop some 15% (dilute with water) into a plastic bag with the salmon inside and its ready in a couple of days
perfect for moss on driveways and nature friendly

That's about how long it takes to de-rust my pipe bracket using vinegar

Us chefs call that marinating..you know.. ;)

What do you buy 30% of?
 

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That's about how long it takes to de-rust my pipe bracket using vinegar

Us chefs call that marinating..you know.. ;)

What do you buy 30% of?

The Acetic acid come 30% proof, and I dilute from that, I only learnt it all in Sweden and a popular way of doing the herrings
 

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Of all the things I've found, dilute Nitric acid is by far the best.
Rust just wipes off. Especially steel and chrome. Also leaves an oxide coating (black) preventing further corrosion.
 

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sounds like all MB owners should be supplied with some! where can i get some?
 
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spock500

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I have left the other half of that bracket in a jar of citric which seems to be doing the job.

Will pop it out after a few more days to see the result.
 

turbopete

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Frontstep

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Would that be the E Class Sub with Avantguarde spec.
 

cleverdicky

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i think i might try this when funds allow me to renovate the 203. sounds like an almost ideal solution. any chance of some more in depth info?

More info in to what exactly ?
When you have a dilute solution in a glass or plastic pot, you just brush it on.
After a few minutes or when it goes black, wash it off.
Brush off any flakes loose rust etc.
ALWAYS WEAR GOGGLES !

Also dont ever use it on brass or similar, dissolves it in seconds. :rolleyes:
 

turbopete

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well ive looked on ebay and theres 69% stuff, and some is 39%. does it matter which? and how far should it be diluted?
 

cleverdicky

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The higher % is obviously better, but way it up to cost. Since you will dilute it anyway.

At a guess (im assuming you wont be using measuring beakers) Approx 15 - 20% in plain water is quite enough for gentle rust treatment. Any higher will get a quicker result but you run the risk of a more aggressive reaction. Also depends how much an area you have to do. A couple of goes and you will soon judge what works for your application.
But once washed off and dried, just paint over it with something like hammerite. DONT remove the black surface.
Lots more detail here. http://en.wikipedia.org/wiki/Nitric_acid
 

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I have used hammerite kurust from halfords about £ 7.99 for 250ml which goes quite along way and it does what it says on the tin
The Hammerite Kurust 250ml converts rusty metal to a clean surface in just 15 minutes.
 


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