Submitted 1 day ago by sundray@lemmus.org to youshouldknow@lemmy.world
https://hackaday.com/2025/12/17/the-lethal-danger-of-combining-welding-and-brake-cleaner/
Makers beware!
Much like with common household chemicals used for cleaning, such as bleach and ammonia, improper use of these can produce e.g. chlorine gas, which while harmful is generally not lethal. Things get much more serious with brake cleaner, containing tetrachloroethylene. As explained in the video, getting brake cleaner on a rusty part to clean it and then exposing it to the intensive energies of the welding process suffices to create phosgene.
phosgene
Fun fact 1: has been used in WW1 as a chemical weapon. Nasty stuff.
Fun fact 2: not everyone is able to smell phosgene gas, so if you work in a chemical plant where phosgene might be around your employer usually does a smell test before you’re allowed in.
I was taught that if you’re in facility that uses phosgene as raw material and smell freshly cut grass, you have a day or two to say your goodbyes.
Unless there’s a massive leak it will oftentimes work out fine, IF the medical services are on top of it early. Everyone entering a facility which uses or contains phosgene will have to wear an indicator strip which tells you the exposure level and will be used as a treatment decision help.
Wait. You shouldn’t combine a flammable spray/residue with a high temperature welding?
Colour me shocked.
I do not weld but could see myself making this mistake without having been informed.
I use brake clean as a basic cleaner for a lot of things in my garage as it does a pretty good job and also evaporates quickly without leaving a residue.
The story tracks my general experiences pretty well
I would guess this mistake is much more common as brake clean is used as a general cleaner by a lot of people
The point of brake cleaner is that it’s not supposed to leave a residue. It’s not actually meant to be a general parts degreaser, but rather a braking surface cleaner. But being able to remove oils without additional water has made it the WD40 of mechanical cleaners. Rarely the right product , but often right enough.
Flammability has nothing to do with it. Read the description and look up phosgene.
This definitely reeks of intentional stupidity and bernard and styro are both part of the group of maker youtubers who are openly doing whatever it takes for views.
That said, this one is at least somewhat plausible. Someone cleans a part with a small amount and a scrub and figures that they’ll just burn it off because they are lazy and don’t care about residue ruining the weld. Whether that will be enough to be meaningfully harmful is an open question
But I can’t think of any situation where you would need enough solvent to remove the rust AND not wipe a part down because it has been soaking for an hour before you took the wire brush to it. At which point this is mostly in the same realm of “only weld in well ventilated places and consider a respirator under that mask” which everyone should do but nobody does.
Solvent does not remove rust.
You degrease the part, then manually remove the rust, then clean with the solvent just before welding. Acetone or alcohol are better cleaners for weld prep than brake cleaner. These solvents are volatile enough that most of the time, the part is dry and not-flammable by the time you get your gear on and are ready to weld.
The really damaging thing here is not the fire but if you use chlorinated brake cleaner when welding it created concentrated chlorine gas and will kill you.
Welding produces a ton of nasty fumes and you should ALWAYS be wearing a welding rated respirator and using a fume extractor when welding, especially with flux core, galvanized, or stainless unless you want extra nasty cancer.
It’s not very likely yo occur but if you watched the video you’d see that this was a real case that occurred.
YSK it’s a bad idea to stick a fork into a wall outlet
I was so happy to see two of my favorite channels collaborate. Both ChubbyEmu and StyroPyro are amazing creators.
Chlorine gas :D
What’s wrong with using a wire brush or an angle grinder to remove the rust?
To be clear, brake clean isn’t removing any rust.
For welding, some kind of grinding is definitely occurring.
If the brake cleaner doesn’t remove any rust, why do they use it?
Wire and rust embedded in your skin is not good. In the eye is worse - I know of people who were wearing both a face shield and full safety glasses who got grinding dust in their eyes.
I don't have a good answer to the problem, nobody else likes any of their answers either from what I can tell.
The time and effort its takes evidently
I read that in Drake’s voice.
Canonical_Warlock@lemmy.dbzer0.com 3 hours ago
Fun fact older refrigerants also broke down into phosgene under high temps. The old school way to identify a compressor burn out was to take a whiff of the refrigerant. If your sinuses started burning from the phosgene then that means you need to do a burn out cleanup.
Newer refrigerants are much more safe, they just break down into hydrogen floride which turns into hydroflouric acid on contact with water. Nothing leaves you quite as invigorated as hydroflouric acid suddenly forming in your lungs, sinuses, throat, and eyes.