Anti Rust Mixture Bath

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alandav123

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Hi all , had a major clearout today and found lots of my old tools that due to living in Arbroath have gotten a serious coating of surface rust...set up my angle grinder with wire wheel one side and a sharpening stone on the other and set about going through all my old chisels, scrapers, axe heads large and small, bolsters, and everything came up gleaming, sharp and looking lovely BUT I also noticed I have collected and stored literally 100s of screw driver bits in every conceiveable size, poxi heads, flat head, hexi drives etc et absolutely reams of these little things which you guessed it are all covered in rust too...Theres no way they will be getting done one by one on the angle grinder therefore I am thinking of trying to make a soultion at home that I can lower them all into and they will come out shiny and nice. I have caustic soda at home and can get almost any legal stuff but does anyone have a nice easy to make up recipe that will strip my screw driver bits of their rust, if so please share it.
Regards Alan
 
How about choosing a proprietary rust remover/converter.

A phosphoric acid based rust remover will leave a protective iron III phosphate film.
 
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The material that came out tops for that purpose in a recent trial was molasses. Yes, I didn't believe it either 'till I tried it.

Dissolve one part molasses in nine parts water Clean off all grease and oil and put in a plastic container with tight lid.

Leave in a warm place for a week.

Messy and smelly but VERY effective.

Please report back results.
 
+1 for molasses

I use molasses on car parts. It is very effective but slow (7+ days) and removes loose paint too.

Be careful to oil or otherwise protect things when they come out as on a warm day you can see the rust re-forming before your eyes!!

I use molasses intended as a horse feed as it is cheap and easy to get in gallons and at 10:1 (ish) you can make up large volumes for large parts.

Do a search on youtube for molasses rust treatment, it is surprising what people make videos of!!
 
In the classic car world de-rusting is carried out with an electrolytic bath which works overnight or a couple of days rather than weeks for molasses.
Fill a plastic dustbin with water and supermarket washing soda mix. A bar across connected to negative lead on 12v battery charger. The items to be de rusted are hung from this into the fluid.
The positive connection from the charger is connected to any sacrificial piece of steel. It really needs to have the same surface area as the parts being de rusted but something like an old brake drum or disc.
After dipping the surface of the fluid will go scummy. The items will be covered in black residue which can be easily hosed off. Paint as soon as practicable before surface rust sets in again.
If the rust is washed off the sacrificial steel it can be used again, eventually the process will eat it away.
 
It may work then, I used roughly 10:1 water as per youtube videos.

I guesstimated it as the treacle was so thick it was difficult to handle.

I will weigh the next mix 10:1 and then see if it differs from a 10:1 mix by volume - hopefully that level of accuracy isn't needed.

Vids said it smells. So far only of liquorice - maybe the smell changes as the reaction takes place.

Anyone know what the chemical reaction is?
 
nigelmercier said:
This molasses thing has got me thinking. Some time ago I had some derusting fluid that was black. No doubt it had phosphoric acid in it, but perhaps molasses as well.
Click to expand...

I possibly bought some of that same pungent black fluid in the 1970's. The distributor was a garage on an industrial estate in Surrey somewhere - perhaps Weybridge direction. As I lived in South London I remember driving down to buy it. I've still got a bit left but it's been in a squeezy Jiffy lemon juice bottle for 30 years. I found it last week when I was having my 10-yearly garage clean out. I wonder if it still works after 40 years?

I've no idea what it was called.

Richard
 
Hi ll, been out hunting molasses and bought 2 x 500g boxes of molasses in a dried form....any thoughts as to ration to mix with water? or is it as simple as 100g of molasses and 900g water...I just want to give it as good a chance to work properly...especially with a weeks waiting time...Alan
 
alandav123 said:
Hi ll, been out hunting molasses and bought 2 x 500g boxes of molasses in a dried form....any thoughts as to ration to mix with water? or is it as simple as 100g of molasses and 900g water...I just want to give it as good a chance to work properly...especially with a weeks waiting time...Alan
Click to expand...

http://www.homercidal.com/molasses/

Well, according to the net, you can go with the ratio of 1:4 or 1:10 - does not mention any ratio in between which I find odd.

So go with 100g : 1000g water (as far as I know - and I am no expert)

My expt is SLOWWWWwwww.

Another source of info said it could take 2 weeks to do its stuff.

It is supposed to smell and that hasn't happened yet (due to fermentation). It is growing mould though. Whoopie! Just what the wife wants in the kitchen. (when it starts to smell I will take it outside ! )

I will be back with photos after 2 weeks.
 
Not sure if the powdered stuff will work at all. We are surrounded by sugar mills here in Oz so no shortage of the stuff (or Bundy Rum).

The wife's father used to run a few horses on their property so lots of molasses laying around, she used to get a spoonful about once a week as a kid.

Don't expect it to work overnight though.

Good luck and fair winds. :)
 
The explanation given at http://www.homercidal.com/molasses/ is confused. "Chelation" is not the same as "Reverse Oxidation" - or "Reduction", as it is usually known in chemistry. Put simply, the basic idea is that the organic matter in molasses provides - when it ferments, I presume - a reducing (low/no oxygen) environment, in which the rust (an Fe(III) oxide) is reduced to more soluble Fe(II) compounds, whilst at the same time substances in the molasses (chelating agents) also combine "tightly" ('chelation' comes from the Greek for 'claw') with iron in solution, also helping to dissolve the rust. It's all entirely reasonable as chemistry, though why molasses should be particularly effective (compared with other organic 'goops') is not explained. Perhaps Sailingsaves can try a parallel experiment with (say) horse manure and compare the outcomes? Anyway, it seems that one can expect good results, but should not hold one's breath (or rather, perhaps one should :)).
 
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