Metal Cleaning Using Vinegar?

[vintage engineerParticipant @vintageengineer]

acid on amzon

[noel shelleyParticipant @noelshelley55608]

Alli wheel or lorry body cleaner is I believe lactic acid ! 10% phosphoric acid will work and as ferrous phosphate is insoluable in clean water will leave a protective coating. Methods that leave a chemically clean surface will start corroding INSTANLY ! I once watched a sandblasted cylinder head turn red in 20 mins.

Any strong acids in untrained hands are VERY dangerous ! Even diluting them is dangerous due to the exothermic reaction that will take place ! Noel.

[MikeKParticipant @mikek40713]

In the States we have naval jelly, which is phosphoric acid. I see Loctite still makes it, but I'll bet only old timers have heard of it. "If it rusts, throw it away and buy a new one" is the thinking.

[Graham StoppaniParticipant @grahamstoppani46499]

While restoring a bike I had five identical rusty nuts taken off a sprocket carrier so decided to do a little experiment. Keeping one nut back as a control item I tried 4 different acid solutions overnight in an unheated garage to see what the comparative results where.

The picture below shows the control item at the front and from left to right:

• 14% sulphuric acid solution;
• Gateros acid salts made to recommended solution strength;
• White vinegar (5% acetic acid); and
• Citric acid crystals made up to 3 heap teaspoons in 200ml aprox water.

The results show that the vinegar was the least effective with the sulphuric not much better. (As a side note sulphuric acid tends to be more reactive with organic materials than metals compared to hydrochloric acid. Harpic toilet cleaner contains hydrochloric acid and can be used as a mild metal cleaner.) The Gateros product left a dark tarnish.

The clear winner was citric acid. It was also the cheapest, costing £5.39 for a kilo from eBay.

As all four products reduced the rust there were no losers and leaving the nuts to soak for longer or in a warmer environment would also have improved the results.

[Neil WyattModerator @neilwyatt]

That's useful, Graham.

I've been using citric acid, and the only downside is the thick sludge on really rusty items. The things I have derusted have finished matt black.

The 'patina' on the gateros one may be iron phosphate, which I tend to think is a 'good thing'.

Neil

[noel shelleyParticipant @noelshelley55608]

Graham, purely on a note of safety, they look like nyloc nuts and as such should not be reused ! Noel.

[Graham StoppaniParticipant @grahamstoppani46499]

Posted by noel shelley on 20/02/2022 11:24:39:

Graham, purely on a note of safety, they look like nyloc nuts and as such should not be reused ! Noel.

You're right Noel. They were destined for the bin anyway so I thought I'd just experiment on them on their way there.

[Nick WheelerParticipant @nickwheeler]

Posted by noel shelley on 20/02/2022 11:24:39:

Graham, purely on a note of safety, they look like nyloc nuts and as such should not be reused ! Noel.

Do they?

And most homeworkshop jobs will allow a nyloc to be reused several times before it becomes loose enough to be just a plain nut. If you can't turn it by hand, the nylon insert is still doing something.

[gerry maddenParticipant @gerrymadden53711]

Graham, thanks for bringing some facts to the table.

A few years ago all the discussion seemed to be about the more 'passive' solutions for removing rust. I think even MEW did a piece on 'evaporust' telling us it was pretty good. Now, not a mention of such things.

I personally have used a lot of citric acid, it works but tends to etch the steel leaving it a bit dull. It can also produce some dreadful bad egg type smells if left too long doesn't go down well in the house, as you can imagine

For these reasons I also tried Arc's rust remover product which I imagine works in a similar way to 'evaporust'. It was totally hopeless. If you just let the parts soak in it for 24 hours nothing at all happened. If one followed the instructions and repeatedly scrubbed the part during the soak, one would eventually remove the rust. But after a few hours of this scrubbing nonsense one cant help thinking that it would have been a lot less mess to have got the rotary wire brushes and the flapper wheels out in the first place.

Gerry

[Andrew TinsleyParticipant @andrewtinsley63637]

I always use phosphoric acid from E bay, works well on badly rusted stuff, if heated. Despite Dave's inability to select the stuff on Ebay, most folk will find the 30 to 50% phosphoric acid without much trouble. It is a lot cheaper than the commercial de-rusting agents that are phosphoric acid based that Dave seems to recommend.

For metal that is not rusted too much, washing soda and a battery charger works wonders.

Andrew.

[Dr. MC BlackParticipant @dr-mcblack73214]

Posted by gerry madden on 20/02/2022 12:13:39:

For these reasons I also tried Arc's rust remover product which I imagine works in a similar way to 'evaporust'. It was totally hopeless. If you just let the parts soak in it for 24 hours nothing at all happened. If one followed the instructions and repeatedly scrubbed the part during the soak, one would eventually remove the rust

Gerry

Arc sell Restore

I used restore on lot of tools that were rusted solid. I diluted the concentrate the recommended amount and used it in a heated ultrasonic bath.

The results were the opposite of Mr. Maddens!

One of the things was a radius gauge set – after some time in the bath, the individual leaves can move separately.

I don't know what components are in Restore – and guess that Shield Technology will NOT be keen to divulge that information! But the SDS may provide a clue!

MC

[Roger BestParticipant @rogerbest89007]

Hi guys, thanks for this. Although a perennial question I have also noticed that there is some development in opinions and experience, even on Youtube.

I posted that vinegar works, but slowly and its prone to flash rusting afterwards, so ok if there is a bottle in the cupboard and you want a modest job done now.

A lot of people love Evaporust for chucks and bits of lathe where you want a good cosmetic finish afterwards and minimal flash rusting. I have two chucks and a face plate that come under that group so expect some feedback.

I suspect that the superior acidic products are for small applications, Jenolite (phosphoric-type acid jelly) is very expensive indeed, OK for spots on cars.

Citric acid is affordable for big items, I will try it on some pitted and big saws I inherited where the propensity to etch is not so important.

Electrolysis works wonders on fiddly stuff like lock mechanisms but won't penetrate deep rust, e.g. surfaces rusted together.

So my collection of hand tools and spanners will probably be done in citric acid or an electrolysis bath.

 

Edited By Roger Best on 20/02/2022 16:17:54

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