What degreasing solvent do you like for general shop use?

I have a variety of solvents or degreasers I use around my home shop and out in the tractor bay in the barn. The water based ones are easy, as they come in spray bottles, and generally the jobs with the biggest area are suitable for these (Spray Nine, Simple Green, or laboratory detergent). The others are a little more challenging to handle. I’m tired of trying not to spill when dispensing some out of a can and onto a rag or paper towel. So, I have ordered two plunger cans. You push down on the top with your rag, and it wets the rag with solvent, without the possibility of spilling. I am going to put the larger one out in the barn, and the smaller one in the shop.

I’m thinking mineral spirits or light naptha for the barn, something chemically similar to paint thinner but quicker to evaporate. Maybe I can find Stoddard solvent, as that sounds ideal, though I don’t remember seeing it at Home Depot. The typical use would be cleaning up after lubrication or after a machining job. I’d often want to be cleaning painted surfaces without ever attacking them. I often use the approach of leaning against the surface to be cleaned while wearing a nice shirt, especially shortly before going out, but this is just all the more reason to get a better “solution” to the problem.

For the shop, it’s more often that I am cleaning bare metal, perhaps in preparation for painting. I’m thinking acetone, or toluene or xylene, or even methyl ethyl ketone. It’s OK if this application isn’t safe on paints.

I grew up using gasoline in open containers, but I don’t like that because it’s so easy to get an explosion, and the fumes are worse I think. Nowadays they have taken out the tetraethyl lead, so I guess it’s a bit better, but still. Some mechanics like to use diesel fuel, and I certainly have plenty of that on hand, but I do NOT like the stink it leaves on absolutely everything. The same goes for kerosene. I also used chlorinated solvents in my youth, especially tetrachloroethylene in the '60s, and it’s nice that they won’t ignite, but they seem more unfriendly to the liver. And I used benzene but these days nobody wants to touch the stuff, so good riddance to that.

What do you like? Why?

I use spray brake cleaner a lot for small areas. Laquer thinner or xylene for wiping down for painting. Depending on what I am cleaning maybe simple green/purple power. My dad had a 5 gallon can of “safely solvent “ to soak things in that I can get refilled at the local bulk oil jobber. I do have a gas can with old gas that I will use for soaking things if I can set it outside.

The best was Berreyman’s (sp?)carburetor cleaner in the gallon can with the parts basket. They must have changed the formula because now it is worthless.

MEK is nasty, I wouldn’t use it unless I had the the proper PPEs.

I often hear how nasty MEK is. It is methyl ethyl ketone, whereas acetone is methyl methyl ketone, a slight structural difference (one extra -CH2- group in one of the two branches) that makes acetone a bit more volatile.

Are they really much different in nastiness?

I had this bright idea of picking up some heptane, but have not gotten around to it.

I used to love hexane because of the smell. I’m pretty sure it was the solvent for Carter’s Rubber Cement in the 60’s, which I used to play with.

And a few years back I had a decent sized bottle of pentane, and also one of tetrachloroethylene. Pentane is so surprisingly light, 0.62 kg/l, and tetrachloroethylene is 1.62. Quite the contrast!

Not that I am planning on sticking my nose in the bottles and enjoying the bouquet, but perusing the Fire Protection diamonds I see that pentane, hexane, heptane, and butanone are rated 1 (out of 4) as health hazards (along with methanol, 2-propanol, acetone, etc.); tetrachloroethylene and chloroform are rated 2; and tetrachloromethane and benzene are 3/4. Not that these are fine distinctions, but there is supposed to be a rationale behind it, for instance, brief exposure to a “1” should cause minimal residual injury.

I still have half a small bottle of benzene sitting in a cabinet, but not sure what I might do with it. It gets gum and tape off, but is not something I want to splash all over the place.

Just wanted to mention Carbon Tetrachloride. My Dad had a bottle that he used for de greasing and wiping down small items. Of course this was in the 50’s and I don’t believe it’s generally available anymore.

Just be sure when using chlorinated brake cleaner and other products like tetrachloride, tetrachloroethylene, etc, that you are not cleaning a part, like the frame of a car, that you will be welding on.

Because what you may get is phosgene gas. There is no antidote for phosgene. It is one of those “oops I fucked up and now my lungs are gone or maybe I am dead in a few hours” things.

Stoddard or similar is best for grease and oil. Spray engine cleaner is basically that with an additive to make the mess water cleanup. And brake cleaner for fine cleaning. For my parts cleaning tank I use a water based solvent from Eastwood.

Where do you buy Stoddard solvent? I’ve found it at chemical suppliers but no place else.

I’ve come to a tentative conclusion. I want to set up easy preferred access to two kinds of solvent, one for the tractor bay in the barn, and the other for the shop indoors (where I also do electronics, handle some laboratory equipment, and other odd stuff).

In the shop I encounter a wider variety of things I need to clean up. There are lubricants as well as whatever grime is on metal stock. But there are also soldering flux, adhesives from labels and gaskets and little assemblies, and contaminants I never know the origin of. For this stuff, acetone is often useful (as many people here also note). But, acetone is pretty polar as solvents go. There is a strategy in creating solvent systems that says you should mix solvents that are pretty different from one another, because the mixture will handle a broader range than any of the single solvents can.

There is a concept known as “Hansen solubility parameters” from a 1967 PhD thesis. You can locate any solvent on a triangular map according to three parameters: the energy from dispersion forces, the energy from dipolar intermolecular forces, and the energy from hydrogen bonds. You can also locate any contaminant on this same triangle. The closer a solvent is to a contaminant in this map, the better it will work. And, a mixture of solvents that are widely spaced on this map will be able to remove contaminants near any of the solvents.

Closest to one point of this triangle are highly polar solvents, which deliver big on the dipolar intermolecular forces. The ketones, including acetone and MEK, are in this direction. Since acetone is cheap in fairly pure form, has fairly low toxicity, and dries quickly with low residue, and like many say is a broadly useful solvent, it’s a pretty obvious pick. I could do a little better with acetonitrile but I’ve never played with the stuff or seen it for sale, so, enough’s enough, let’s say acetone.

But toward another point of the triangle are things with high dispersion force. Solvents out this way include hexane, white spirits, xylene, toluene, and benzene, the aliphatics and the aromatics. They actually make more effective solvents for petroleum based lubricants and residues from petroleum fuels. Therefore I’m picking something out here to mix with my acetone. Because benzene is so toxic, and xylene is a bit slow to dry and greasy feeling, I’m going with toluene. Nowadays, toluene has a bad name and limited availability because kids tend to use it to get high, but this is here in my own shop where there’s nobody to do that, so that’s no problem. I also thought of hexane but I’m not sure if it might dry too quickly. And I don’t want to analyze this more than is worthwhile. I know toluene and it’s satisfactory, so we are going with toluene. I’ll say more about white spirits in a bit.

The third point of the triangle is where hydrogen bonding forces predominate. This is where water excels, and the alcohols also do well. Removing salty sweat and grass stains is out in this corner, like various other laundry challenges. But adding a strong hydrogen bonding strength solvent to a system can have negative effects like causing the other solvents to separate out into two phases, and drawing atmospheric water out of the air, encouraging rust and corrosion. And the kinds of cleaning challenges that live here are less often what we deal with mechanically, and more what we hose off in the driveway with Simple Green. Well, I have water and 91% isopropanol and various soaps and detergents conveniently available anyhow, and for some contaminants I’m quick to reach for them, so let’s say I have these needs covered already.

Therefore, for my strong, quick drying, low residue, versatile solvent in the shop, I’m going with a 50/50 mix of acetone and toluene. I also found an article that described this blend as an ideal laboratory solvent for dealing with a broad range of unknown contaminants. Sounds pretty good to me. I’m going to fill my new 1 quart plunger can with this in the shop.

Now, about the tractor bay in the barn, let’s get back to white spirits. There is more or less of a family of solvent mixtures distilled from petroleum. These petroleum distillates come by different names including paint thinner, naptha, white spirits, Stoddard solvent, deodorized whatever, and even charcoal lighter fluid. They are toward the high dispersion force point of the triangle, but then so are other petroleum products like lubes and fuels, so around a tractor or other power implements they are a pretty useful product. I’m going with a light, deodorized distillate on this one. Safety and cost and availability are all excellent. It will be a bit different from the shop mix (acetone/toluene), so if one system doesn’t work well I can take a quick stroll to try the other. This is why I didn’t pick the light petroleum distillate for inclusion in the shop mix. Besides, these light petroleum distillates tend to be safer on paints and plastics and other things I don’t want to ruin. And they’ll be kind to my white shirts (in fact Stoddard solvent was originally made as a drycleaning fluid for nice clothing). This is what I’m putting in the two quart plunger can in the tractor bay. And I’m picking something deodorized. I’m done with using gasoline and kerosene, and stinking all day.

Not good. They’ll give you brain damage. One whiff will confirm.
Had a printing company owner replace regular blanket (solvent) wash with toluene and MEK on different occasions. He bought 45 gallon drums of the stuff thinking he was saving money. In actuality the regular blanket wash was cheaper. After initial trial, which didn’t last long, we (staff) refused to continue using them. OK, we did use the MEK occasionally as blanket fix. It raised the rubber as a temporary damage repair.
Eventually Workers’ Comp. happened by on a spot check. They sealed both drums and ordered the owner to get rid of the stuff.
Side note; that was many years ago. These days the industry uses a water miscible wash. It works well without damaging rubber rollers.