Rust removal

Been using it for 4 years. Simple, non-destructive, very effective and a lot safer for the gonads than a rotary wire brush. The only issue is disposing of the residue which no doubt contains iron and all sorts of nasty things formerly used in paints. ttfn Roland

"Roland Craven" wrote
The only issue is disposing I've been thinking about this off and on, Roland. If my drain is blocked, I go and get some caustic soda in a very concentrated solution in order to clean it out and nothing that the non-caustic solution can remove from the iron could match that for unpleasantness, surely?
I've got some P55 barrels that could do with de-rusting .................
Regards,
Kim Siddorn
I'd rather have a free bottle in front of me than a free frontal lobotomy!

...and so do I but OTOH I don't throw any of the following old paint constituents in to clean drains: lead, cadmium, zinc, write your own list! e.g That nice white primer filler they used was calcium plumbate based. Electrolysis removes all the old paint (but not modern plastic paints), and is also good for removing burnt on carbon. It is line of sight so careful electrode positioning is essential. I put a 12v battery in circuit to keep the current down as all excess current does is to decompose the water thus creating potentially dangerous quantities of hydrogen (of which some is produced anyway- which is why I do it outside). ttfn Roland

Kim, did you see that ex-railway signal pulley wheel that was sitting in my conservatory ? (aka backup junk store) I've electrolysed half of that so far, which has done a beautiful job. Despite being coated with at least 30 years of grot, it has emerged with a smooth as-cast surface.
Halfway through tanking, it turned bright pink ! I presume this was a layer of lead (?) primer.
-- Die Gotterspammerung - Junkmail of the Gods

well, i must admit i was very intrigued about this one. i waited till the missus was upstairs,got one of her stainless stell spoons (which i bent into a horseshoe shape!) placed some rusty head bolts in and ALAKAZAM-absolutely superb. i have a dual power supply and when parallelled up at 40 volts/6a (ish) really made the snot fly-thanks for the tip

I hate to be a nag but SS contains Chrome and other metals which end up in the electric soup and are better not tipped down the drain. regards Roland
parallelled

- with my tongue firmly in my cheek .........
Surely, a man who runs a machine that fills the air with unburnt hydrocarbons, oil vapour and noxious compounds - to say nothing of carbonised oil - cannot truly care for the environment.
Scrap all the M series Petters I say, hot fog to the fore!
(Smartly ducks, hides and runs off giggling)
Regards,
Kim Siddorn
(who has spent his life burning petroleum products in one big engined vehicle or another !)

Yes there are some that prefer, sulphur, vaporised phenols etc etc :-) At the risk of (becoming?) tedious, most sewage works are not equipped to remove heavy metals so it goes into the rivers where I catch and eat the fish. Pure self-interest :-) 15 all Siddorn to serve..... regards Roland

River fish? Nasty, muddy things fit only for Gollum and similar tickling fishers.
In any case, I'm given to understand that few heavy metals are dangerous in their pure state, it is the compounds that they form that are dangerous. Lead pipe, for instance, quickly forms an oxide on the inside which renders it inert after a few days of use. Hence, generations of us drink water out of lead pipes, cook in aluminium saucepans and have our rotten teeth stuffed with mercury.
Which may go some way to explaining something about many of us on this newsgroup, I suppose ;o))
I think that might be 30 - 15, but I don't know much about golf, I admit.
Regards,
Kim Siddorn
Tu quoque ? ;o))

Rather than a debate for which I at least am not qualified I restate my point. It is neither necessary nor beneficial to the process to use SS. Simple MS will do just fine when it gets all claggy just hose/scrub and re-use til gone. ttfn Roland

- but the fishing and the golf? ;o))
Point taken Roland - certainly no offence intended.
Regards,
Kim Siddorn

Coming into this as an interested bystander :-)) I have printed out and read the BHI FAQ which was very interesting, and also had a look at the methods used in the process.
In the BHI FAQ the use of a stainless steel electrode is acceptable with no loss of leeching (leaching?) out of chromium into the electrolyte mentioned.
In a similar discussion on the Atis list there are all sorts of horror stories about compounds and chemicals etc that would make your hair curl...
I feel that Roly is probably right to use basic mild steel, although no mention is made of iron, and that safety first should be the message we should all be preaching.
Now, looking through the dark underneath of the benches in the workshop, I find that we have a number of low voltage high current trannies, all from various projects that either didn't go ahead or that were modified and we never threw the old design away (we NEVER throw anything away here!) These are not small, and weigh 20-30lbs each, so first class post is NOT an option.
We also have a large supply of new 25A rectifier bridges.....
We can make same available at no cost other than transport to anyone interested in experimenting with this process, subject to availability and limit of one per person. I think we have at least half a dozen, maybe more. It would clear out the old stuff and leave us a bit of room, and hopefully would enable folks to have a play at less cost than if they had to buy the parts.
Current ratings are between 15A and 40A, depending on which tranny.
Anyone interested, please contact me off-list at the factory email address.
Due to another leaking radiator, I won't be going to Sodbury this weekend, so transport will have to be arranged by other means.
Kind regards,
Peter
Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk

Interesting because I did use an SS electrode briefly and it was depleted. I find 2-4 amps (from a cheapo battery charger) more than enough and that more amps simply produces excessive heat and hydrogen. I have tried CI but it soon stopped working. I don't know why but suspect a passive coating was created. Your experience may be different ttfn Roland PS We had a plating shop nearby for a while but a few drain discharges soon got it closed.

As we own a PCB manufacturing company, the discharges into the local drains are fairly closely monitored by the local water company.
Most etchant is ammonia based and we lose most of that by evaporation rather than down the drains, and it is just topped up at regular intervals.
The other chemicals aren't too bad, but the Tin stripper needs a lot of dilution/washing to reduce it to levels that would be acceptable, and the factory has a 2000 gallon tank upstairs and non-return valves everywhere in the feeds :-))
I am going to have a play at this rust removal thing, but first of all I have to sneak a poly tank out of their workshop without anyone noticing it!
BTW: We have loads of 25 litre blue drums (empty) if anyone wants one as a temporary tank, they are chemical grade containers and very heavy duty with screw on top. Cut in half or just the top quater taken off they make a good small container, Free if anyone wants any... We use them for the horse water BTW, they are quite safe once washed a couple of times.
Kind regards,
Peter
Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk

Molasses also works very well to remove rust. Mix up with half water, put your parts in and let it soak. Every week or so stir the mess up and gently blow air into it if you can. The rust is removed by bacterial action. This works well but is very slow, may take several months. A good source of cheap molasses are feed stores where it is sometimes used as supplement for horse feed.

I passed the BHI sheets over to Allan at our other factory to comment on. Allan is an ex-ICI chemist/physicist so I asked for his comments re the stainless steel aspect and the process generally.
He agreed that with the anode depletion the constituent parts of the stainless steel will go into the electrolyte, although he also thought that there would be a way to recover that out of the electrolyte back into metallic format if a bit of thought was applied.
He mentioned Phosphoric Acid, to which I was able to recount my own experiences with surface damage through the acid attacking good material as well as the rust, and that soft iron vastings were likely to be attacked more than harder grades.
The possibility of recovering the chrome sounds like an interesting excercise, I'll tackle him about that one later on....
Kind regards,
Peter
Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk

The other thing to come out of our conversation is the use of a carbon electrode instead of metal, there are no deposits from the anode onto the cathode, so anything conductive would presumably fit the bill, and carbon is pretty much as safe a product as you can find.
Kind regards,
Peter
Peter Forbes Prepair Ltd Luton, UK email: snipped-for-privacy@easynet.co.uk home: snipped-for-privacy@easynet.co.uk

Only for a chemist though, not for engineering quantities.
An electrolysis setup is basically an electroplating setup, but with a different electrolyte.
As is well known, electroplating needs a cyanide compound to work really well. Simple salts are nothing like as efficient. The metal cyanide complex is a more efficient transport for the metal ions. The washing soda electrolyte in an electrolysis tank is en even more simple ion and is effectively incapable of transporting ions for plating.
-- Die Gotterspammerung - Junkmail of the Gods