Consequences of Machining Cast Iron

[SamsarandaParticipant @samsaranda]

[SamsarandaParticipant @samsaranda]

This story starts about 18 months ago at the start of the first lockdown, we had our downstairs cloakroom completely refitted, everything was renewed and it looks very smart and the wife is very proud of the result. For the last ten days I have been machining cast iron castings in the workshop, it is a very mucky job but the end result is very pleasing, as long as you don’t hit too many chilled areas. Usually when I come indoors from the workshop I wash my hands in the kitchen sink, which is stainless and easily cleaned afterwards, sometimes the kitchen sink is otherwise occupied and that means I use the downstairs cloakroom which has a small rectangular plastic composition sink. When I washed my hands last evening I could see some little orange dots on the bottom surface of the sink. These dots appeared to be fixed to the plastic surface. It didn’t take much working out that the dots were from tiny particles of cast iron that had washed off from my hands when cleaning up after machining in the workshop. My first thought was panic if the wife sees rust marks in her cloakroom sink then I’m dead, so I got some cleaner to remove the evidence, I used a well known “Lime and Grime” cleaner because it was non abrasive and wouldn’t damage the plastic, it was only partially successful, it removed most but there were a few dots remaining but nowhere near as conspicuous as before, I reckoned that as the wife has cataracts she would probably not see the few remaining dots, fingers crossed. I hope this helps stop anyone else suffering the same problem.

Unfortunately have upset the wife in the past when she had one of her pristine white classical garden statues located adjacent to my workshop door and I had been using a grinder to shape some steel pieces and the dust from grinding drifted towards her statue, everything looked fine until a couple of days later after it had rained and the statue ended up with orange spots on her feet. That episode ranks alongside the one where I was using my hand held grinder in the garden near the rear porch and wife subsequently found particles of metal embedded in the double glazing, I will have to stop living dangerously. Dave W

[Pete RimmerParticipant @peterimmer30576]

Get some 'Iron Out' wheel cleaner. It's purpose it to remove the particles of iron that come off car brake discs and embed themselves into the paint/powder coating of your car wheels. It's fantastic stuff.

P.S. if it melts your sink it's your fault not mine 😀

[SamsarandaParticipant @samsaranda]

Pete

Thanks for the info, never heard of “Iron Out” must be worth a try. Dave W

[Simon CollierParticipant @simoncollier74340]

I have a pump pack of sorbolene cream and roll of paper towel in the workshop and do a pre wash with this when leaving the workshop. I also put these in my tool kit when I run my engine. Gets most of the stuff off your hands and easy on the skin as well.

[martin haysomParticipant @martinhaysom48469]

i put an old Belfast sink under my outside tap useful for gardening as well

[not done it yetParticipant @notdoneityet]

One should never ever scrub a SS sink with wire wool. It might depend on the grade of stainless but that is the usual warning. I expect that iron dust might also cause rust marks if left to rust. Best to use a ceramic sink/basin – or just wash hands under an outside tap.🙂

[Mike CrossfieldParticipant @mikecrossfield92481]

I keep a bottle of Jenolite rust remover under the stainless sink in my utility room, and when I see the dreaded red spots a quick rub with a few drops on a cloth soon removes them. The key ingredient of Jenolite is phosphoric acid.

[SamsarandaParticipant @samsaranda]

Much useful advice being preferred which I am taking on board. Dave W

[Tim RoweParticipant @timrowe83142]

Another option is a yacht chandlery or buy online. They will have rust stain removers for use on GRP boats and the active ingredient is oxalic acid. Very effective.

Tim

[Martin ConnellyParticipant @martinconnelly55370]

I had a car that had particles from abrasive wheel use sprayed on it and I didn't know until it had got damp and the particles turned into embedded rust. Luckily it was an old car with 150k on the clock that was going to the scrappy soon anyway (I still did another 18k before then though).

At work where we used a lot of stainless steel we had to separate out tools for stainless from tools for non-stainless steel. Cross contamination on the stainless soon showed up when condensation or rain got involved.

Martin C

[OldironParticipant @oldiron]

Just a little aside to this topic. We have a caravan with a S/S ? sink in the kitchen area. When I laid it up for the winter a couiple of years ago I left a bottle of Fairy Liquid sitting upright in the sink. It sat there through the winter for about 3 months. There must have been a smudge or drip of the contents onto the surface where the bottle sat. When I got the van ready for the season I found a small hole in the bottom of the sink and an obvious ring of corrosion around it where the bottle had been sitting. Just goes to show you never know what is in any product you buy however harmless it seems.

regards

[not done it yetParticipant @notdoneityet]

That was likely salt. Used as a thickener in the product. SS does not like chlorides!

[Bo’sunParticipant @bosun58570]

Another vote for Oxalic Acid. Used to work in a foundry, and despite how well it was filtered and scrubbed, cast iron dust escaped into the atmosphere and onto peoples cars. At the time, Oxalic Acid (bought in crystal form) was the go to product.

[jaCK HobsonParticipant @jackhobson50760]

I have to wash my hands before I can wash my hands in the sink. If I'm down the workshop and then have a shower, the shower tray ends up with little orange spots all over – I'm probably going to need to have a shower before I'm allowed in the shower.

[Rik ShawParticipant @rikshaw]

"has a small rectangular plastic composition sink"

Loads of oxalic acid in rhubarb leaves. Give it a rub with one and hope it doesn't crumble

[Russell EberhardtParticipant @russelleberhardt48058]

+1 for oxalic acid. Also good for cleaning teak on boats.

Russell

[Howard LewisParticipant @howardlewis46836]

Yes, have to scrub the S S sink in the utility room with a green scrubber to get rid of the rust spots after washing from working in the 'shop.

Would never hear the end of it if I did the same to the sinks in the kitchen or cloakroom! Probably grounds mfor a divorce, on the grounds of unreasonable behaviour.

Definitely +1 for Oxalic acid, or a Stain Devil perhaps?

Howard

[KWILParticipant @kwil]

Always wear a mask when machining cast iron, the carbon particles are vey fine and not good for your health.

[old martParticipant @oldmart]

I remember how deglazing brake drums in the sink used to leave little brown spots stuck all over the stainless steel.

[Chris CrewParticipant @chriscrew66644]

I had a similar issue with a beige coloured kitchen sink but managed to remove the rust spots. From that time onward I have kept a tub of Swarfega in the utility room adjacent to the kitchen then pre-wash my hands at the outside tap. It kept the peace until she had a new kitchen fitted with an expensive black sink that she managed to spoil by emptying boiling water directly into it. That was just 'wear and tear', of course, because she had done it herself and not the end of the world event that I had inadvertently caused and rectified.

[Fowlers FuryParticipant @fowlersfury]

Topic covered on here several times in the past.

I use Jenolite, painted on to the dried surface of the sink at night after working with CI. Next morning wash sink with water & all traces of rust spots gone from the acrylic and no aggravation form SWMBO.

However, potentially bigger sources of ear-ache can arise from the carbon particles deposited on clothes & in hair. These contaminate – so I'm informed – "everything around the house".
I've tried in vain to explain that machining close-grained cast iron is one of the few pleasures left to an old man.

[Roderick JenkinsParticipant @roderickjenkins93242]

Our kitchen sink is black

Serendipity, the previous owner of the house did a makeover. I also have a dedicated dark handwash towel.

Rod

[Howard LewisParticipant @howardlewis46836]

Oh Yes,

Black or dark grey towels are a MUST after the workshop. You MIGHT get away with a heavily patterned dark one

That way you won't be accused of "Making my towel dirty", until it goes for washing!

Some towels and clothes are not allowed in the washing machine. Only handwashed, in the utility room sink!

Such is life

Howard

What I forgot say is that when machining cast iron, I try to site a powerful magnet under where the swarf is likely to fall, covered with newspaper. In this was most of the swarf is attracted and caught and can be tipped away more easily once the newspaper has been taken away from the magnet.

If the magnet starts to grow "whiskers", Blu Tack is a good way of removing them and cleaning the magnet.

Edited By Howard Lewis on 14/08/2021 12:45:27

[SamsarandaParticipant @samsaranda]

Further update, wife has completed her weekly in depth clean of both bathroom and downstairs cloakroom, no mention made of orange spots, I must admit they have faded and are only visible now if you really search for them, so I think I can breathe again they were not seen. Dave W

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