Mr Whippy 0 Vs corrosion 10

[momec3]

Same goes stainless on stainless, must use antisieze or both bits lock real good.

Chris

[PeterB]

G'day Gary,

1. Whilst using stainless fasteners can be painful, for the corrosion issue you mentioned and for galling (i.e. 'picking up' a thread and binding), I still like using them! As you mentioned, using anti-seize helps with both issues. 'Passivation' of stainless fasteners is also used to address differential corrosion issues. (Passivation = "the chemical treatment of stainless steel with a mild oxidant, such as a nitric acid solution, for the purpose of enhancing the spontaneous formation of the protective passive film".)

2. Another very simple method of removing rust from ferrous materials is immersing the rusty item in plain old vinegar! I tried it with a rusty axe head, putting it in a plastic container with some white vinegar from the pantry (don't tell the missus ) and it done great job! Every bit of rust was dissolved, leaving a nicely etched surface.

Cheers, Pete

[PeterB]

Whoops, I didn't see Chris' response. Sorry for doubling up about galling of stainless on stainless.

Pete

[OLDtimer]

All this scientific stuff & it all comes back to good old vinegar! (not bad with a drop of orange juice to take the bite away !).

[Dr Goggles]

Molaasses tanking is a good way too.... not fast but thorough...and the residue isn't too nasty, you do need to degrease things first.

[Rob]

I used molasses extensively for old Ford parts and panels in the 90s.

10:1 for ten days in an otto bin and simply tipped the residue onto the lawn with no ill effects. It will even remove any original old paint. Tie the part(s) to the lip using plastic coated wire to save you dumpster diving.

Don't put any soft metals in or it'll be gone & by soft I mean any alloys or pot metal.

The only down side is the stink, when down wind you'll think you've stepped on a "mine".

Another good one if you live on/near an orchard is dropped fruit. I've not used this one but been told of it by a few old guys.

Both processes are slower in cool weather.

[BIG GAZ]

Dear Dr,
Dreamliner (Graham) is a chemical engineer as far as I can remember so I wouldn't discount his comments too quickly. I might PM him to get his expanded view.
GAZ

[Dreamliner 200]

Hi Guys, yes it's true I am an industrial chemist, I recall having a conversation with Paul (Penny) about corrosion prevention etc. and wondering what was in Salt X etc.

To be honest, it was a couple of years ago and I don't recall in which context we discussed the use of vinegar, although obviously it is an (organic) acid (acetic). There were a couple of processes under discussion, 1) Salt removal or prevention of sticking and 2) corrosion removal / prevention.

Not sure on the salt dissolving issue yet, the good Dr is quite right in that salt NaCl is inert (unreactive) and literally the salt of a metal in this case with a halide (Chlorine) so think of sodium metal dissolved in HCl (Hydrochloric or muriatic acid) you would get (put simply) Sodium Chloride (salt) and hydrogen evolved.

I tend to use solutions of phosphoric acid for cleaning corroded steel parts, as this leaves a basic phosphate coating, preventing flash rust and giving a good key for paint.

Aluminium is different altogether, steer clear of strong caustic (Sodium or Potassium Hydroxide) based cleaners, they will dissolve aluminium. Metasilicate based ones are good and acids such as sulphuric and phosphoric combined with a 'nasty' Hydrofluoric acid work well, most acidic wheel cleaners are like this. Wetter and surfactants are key in improving these processes, particularly for soil and corrosion debris removal.

I'll keep looking into the Salt X / Salt away thing, but to me they seem a bit odd, can't work it out yet.

Cheers Graham

[Dreamliner 200]

Oh I forgot to add, Molasses is what's left over from refining raw sugar, it contains several organic acids, Citric, Lactic and gluconic and others.

As Rob says, its gentle and effective if a bit slow, I suspect some anaerobic bacteria get in there too (hence the smell) and as a by product of their metabolism also produce acids, particularly in pits and crevises.

When rinsed, these all flush out and leave the corrosion pits free of rust.

[Greg Watters]

I think salt x is basically phosphoric acid and detergent
one of the members tested some on metal strips several yrs ago and came up with that conclusion
i will let him post if he feels the need as i don't trust my accuracy of a conversation several yrs ago