Acetone vs Isopropyl Alcohol

[Jake M]

Ah interestingly, MEK is available on Amazon UK. So much for some people's perception that the UK is health and safety gone mad!

Looks like nasty stuff mind you but then acetone is pretty nasty too.

Turns out the UK government site is pretty relaxed about MEK. Maybe it's the answer.

MEK isn't on the naughty list for being much more hazardous than many others as a solvent, it's more an environmental thing. (Not "that" environmental thing, this stays low.) It evaporates into heavier molecules, which are not prone to breaking down, and just don't go away. Ones in the air that stay near the ground and nucleate smog, and ones that get caught, "rained" down to the ground, etc, (which they will in much shorter time than the ones that get stuck in the upper atmosphere), they get in the ground water and kill or damage a bunch of things, and they persist a very long time there, so it depends on amounts. So more about it's local/regionnal popularity and popular use, whether the local environmental departments are seeing actual presence of it (or it's byproducts, I'm not sure which) building up faster than it's going away. Which is, as usual, where the problem arises.

 

[Martin W]

1969 or 70 two brothers were cleaning bike chains in a pan of gasoline in their storage room attached to their parents house. Gas hot water heater was in room. Fumes ignited. Both died from their burns. Pretty much then in Arkansas everything was natural gas powered.

When I was a kid, my buddy was cleaning his chain in a pan of gasoline in the basement. The dryer pilot light was right beside him. When it ignited the whole house shook, then the fire went out right away. He never got burned other than singed all his hair. When he went upstairs , 1/2 the insulation in the attic got sucked out into the hallway.
Had some splainin to do when his dad got home from work!
Martin

 

[Smithdoor]

So, last year when I got my little 7x14, I did the inevitable strip, degrease and clean (and all the other things, natch).

Having by this time, watched a fair few Blondihacks videos, I gravitated to using acetone for the degreasing.

When I was in my workshop, yesterday, I noticed I still had most of a 5l container of IPA (no, not India Pale Ale; there'd be no chance of that lasting in my household!) up on a shelf.

Now, IPA was what I used to use for cleaning and degreasing mechanical parts of flight sim peripherals (joystick gimbals, pedal mechanisms, etc) before I realised I was a terrible sim pilot, both rotary and fixed wing and stopped enjoying myself.

I don't think I've noticed any significant difference in cleaning and degreasing performance between IPA and acetone, although maybe I've not got to the limits of one or the other's capabilities.

So finally the question: can anybody offer any good reason, other than personal preference or habit, for using acetone over IPA, or indeed, IPA over acetone?

(Bonus points for people that answer using their BSc/MSc/PHD or industrial chemist's knowledge to provide a senior high school level answer; which is, as far as chemistry goes, where my capabilities end )

Remember Acetone is finger nail paint remover. It will remove most paints and plastic coatings.

Dave

 

[durableoreo]

When I was a kid, my buddy was cleaning his chain in a pan of gasoline in the basement. The dryer pilot light was right beside him. When it ignited the whole house shook, then the fire went out right away. He never got burned other than singed all his hair. When he went upstairs , 1/2 the insulation in the attic got sucked out into the hallway.
Had some splainin to do when his dad got home from work!
Martin

It's hard to overstate the danger of gasoline. One of the major issues in submarines, back in the day, was getting enough power out of the engine. It was a power per unit volume or something like that. Gas engines could do it but there were so many accidents due to the volatility of gasoline that even the Navy eventually had to give up on it. Eventually diesel technology improved and progress continued.

I had a pastor once who wouldn't make hospital calls. Apparently a friend of his had tried to light a bonfire with gasoline. When he struck a match, enough vapor had evolved off the gas-soaked pile to cause a deflagration that burned more than 50% of his skin. (Deflagration is like an explosion but it's caused by heat rather than pressure.) He was a young man when it happened so it was a powerful association.

I knew an assistant chief of the fire department in Rochester, MN who had answered a call in which a child was burned over 95% of his body. The father was mowing the lawn and burning sticks. The plastic gas can was somewhere in the yard and his son, while fooling around, balanced it on top of the fire. This was part of a stop-drop-and-roll talk so I think you can imagine what happened next. The only part of his body that wasn't burned was the bottom of his feet.

I haven't gone looking for these stories. They are incredibly common. Beware of low vapor-point solvents.

 

[7milesup]

One of our members, @NCjeeper, nearly lost his life and his shop due to spilled gasoline and the subsequent fire.

 

[AllenV]

First I'll point out that I don't have a pilot light in my shop and that I take care to put soaked cloths outside to evaporate when finished.

If I am regarding paint as a contaminant, then I use the cleaning method based on my experience in semiconductor electronics fabrication. The gold standard here WAS TCE (trichloroethylene) followed by ACE (acetone) and then ISO (isopropyl alcohol, we did not call it IPA). Then a final rinse in deionized water. Do not let the parts "dry" between solvents as that leaves a residue on the surface. Heated baths were the best. Eventually TCE was recognized as a carcinogen and removed from semiconductor processing. Then we used ACE, ISO, DI. That was okay, but not as nice as the TCE brew. (This is in a research lab, NOT a production facility where cleaning means the difference between printing money and going out of business. Production cleans are very serious business left to skilled chemists, not scientists.) The main reason for the ISO following ACE was to remove a slight residue that ACE will leave on the surface. The wet transfer allow the ISO to displace the ISO. Out of DI and blow it dry with dry nitrogen.

In my home shop I use just ACE or ISO depending on the nature of contamination. ISO is not as good as ACE at degreasing but does not evaporate away so readily.. If I am being especially critical I’ll use “wax and grease remover” sold at automotive paint shops for cleaning panels prior to painting. However the wax and grease remover is easily the most expensive. I don’t bother with a water rinse as that just starts rust and corrosion, and I am not making diode lasers.

On Painted surfaces: WD40 and/or mineral spirits get most of the crud off. Then a wipe down with ISO to pull off the last of it.

Sometimes with smaller items I’ll use the parts washer which has PSC1000 solvent (from Tractor Supply)

 

[Shotgun]

Diesel really stinks, but there is low-odor tiki torch fuel, which seems to be a light diesel with a lot of the smelly parts removed that works just as well. Still stinks, just not nearly as badly.

 

[RJSakowski]

I really miss the trichloroethylene. It is far and away the best degreaser and it is nonflammable. However, in the presence of an open flame, it does produce phosgene, a notorious WW I gas.


All solvents have their bad sides and they should be understood whenever solvents are used.

 

[SouthernChap]

All solvents have their bad sides and they should be understood whenever solvents are used.

Well, I've learned a load in this thread and from following up comments with my own searches, my understanding is an awful lot better than it was.

 

[woodchucker]

I really miss the trichloroethylene. It is far and away the best degreaser and it is nonflammable. However, in the presence of an open flame, it does produce phosgene, a notorious WW I gas.


All solvents have their bad sides and they should be understood whenever solvents are used.

I detest TCE. We bought a house in the mountains... Our water test came back with extreme levels of TCE, there were fire roads going in to the woods, and companies would dump all soughts of chemicals in there. Years later they caught a guy dumping 55 gallon drums in the reservoir nearby. I bailed on the house, as my son was about 3 months old, and we were told by the experts at my wifes think tank (at the time) that 2 carbon filters would work, but any more release of chemical would fail... I could not risk it.