Muriatic acid mistake!

When I was in high school, one of my classmates poured liquid drain cleaner (concentrated lye solution) thru an aluminum funnel. He lost his eye.

Drano (non-liquid) contains aluminum "swarf", which reacts vigorously with the lye once you pour warm water down the drain. The bubbling action is caused by the release of hydrogen in the reaction. Don't light a match.
 
A 100% effective and safe way to derust Cast Iron is degrease with a detergent and pressure wash then soak in a 1:40 mix of Molasses/water.
Pressure wash after soak and repeat if necessary. After rinse treat with a Tannin base rust converter and inside you will have about a year to paint or you can oil with a fish oil which can be painted at any time.
Soaking can take a while but no damage to sound iron will occur. Bigger items can have soaked rags wrapped on them and then wrapped in plastic 'cling film'. With tape I've used this on old vehicles using duct tape.
 
Be aware that when you clean with acid you will induce hydrogen embrittlement. It is a very real risk and seemingly solid steel parts will snap like a biscuit. I even know of tank armour that was acid cleaned during manufacture that failed ballistically to stop rounds of 1/2 the diameter it was supposed to be rated at.
 
The One Thing to REMEMBER when using ANY Chemicals for cleaning, or Whatever is

"ALWAYS KNOW & have readily Available the Neutralizer for THAT Chemical".
"Always STORE them in separate areas"!
"ALWAYS KEEP AN MSDS LOG BOOK of All Chemicals you use in your work" (MSDS = Material Safety Data Sheet)

That last one should be readily Available to ALL Persons around your WORK AREA"

~~~ Philip, who spent 5 years as a 'Company' "CAL-OSHA Safety Officer" (every company over 5 employees is/was REQUIRED by LAW to have a designated CAL-OSHA Safety Officer, AND have MONTHLY Safety Meetings ! ! !
 
Phillip. A mine I worked at had one of those safety meetings every Friday morning. Management used it as primarily their opportunity to tell us all to work harder so they could make more money. We used it as an opportunity to point out the dangerous/unsafe things we had noticed. Typically 20% of what we mentioned got acted on.
Cost was the determiner.
I well remember the 44 gallon drum of 1:1:1 Tricloroethelene cleaner that they washed anything greasy in, even their hands. Luckily the electronics tech pointed it out to me when I first started on the job. He didn't know what it was, but worked on the principal that anything that had cross bones and skull on it was bad news. I got the union to research it for me and from then on wouldn't go within 6 feet of the open drip tray of the stuff.
The rest of them weren't worried when I told them how bad it was, they had used it for years and it hadn't killed them - yet.......
This was back in the mid 80s.
There is OH&S that is just bizarre (place in town has an MSDS for water!!! kid you not), I have seen people having to write essays on safe work, such as how to get out of a vehicle!!! So people get cheesed off with the stupidity and ignore all of it.
But this then trivialises the really important/real danger OH&S.
 
Used to go elbow deep in a Triclor steam powered vapor tank in the 70's.
 
mcostello - the difficult part about exposures is that everyone is different. We have all heard the stories of someone who smoked from the age of 5, lived into their 90s and probably got run over by a bus.
You could be one of the hardy souls who have a higher tolerance of it.
Everything to do with exposures tends to follow the bell curve probability. I will attach a graphic. In short, the majority of people tend to fall into a certain range, which tapers off at each end to the exceptions: the ones who have almost zero tolerance and the ones who seem almost immune.
<http://www.statisticshowto.com/wp-content/uploads/2013/09/standard-normal-distribution.jpg>
As you can see, -2 to 2 standard deviations covers most people.
I was involved many years ago with having to isolate and dispose of an industrial product. I had been warned it was dangerous but could not find out anything about it. When I questioned the company concerned they responded with words to this effect "25% of the people exposed to it occupationally it would kill, the other 75% seemed unaffected, but there was no medical test that could identify which group people were in, so it was banned".
This is also the reason so many promising medicines that we hear about on the news never get to be sold.

However, I have really taken this off topic.
Getting back on topic, if you have patience, a molasses and water tub is a very good way to de-rust steel BUT only mild steel. It will ruin spring steel, alloy etc. The purer the water the better the result. Being able to cover the container is also preferable, the smell is pretty impressive. I can't tolerate the stuff on my skin, gives me migraine headaches!
They always used to say that Phosphoric Acid was the least harsh of the acids for cleaning steel and that it left an anti-rust phosphate coating on the
steel when rinsed off gently.
 
Yeah, read about a guy who had some in his shop and rusted everything exposed to air!
I have a feeling that might have been me if you read it in an electronics forum or something. I can't rule out humidity's involvement, but I still blame the acid for that one, and still have stuff that needs to be cleaned up. The MA has been outside and far away ever since. I hope it's OK in this heat.
 
You can cure hydrogen embrittlement if the part is not yet cracked. I believe that putting the part in a 350 degree oven for a couple of hours will do the job.
 
Thanks for that, I have never seen that mentioned before.
 
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