Solvents in the shop (I hope not too geeky)

[David Utterback]

Most of us keep solvents around for a variety of shop purposes. Probably most common are to dilute other solutions and to dissolve other materials. If one does not work, we can try a different one. But some information about solvent properties can help us select an appropriate solvent for the task at hand. Most importantly, solvents dissolve substances that have similar polarities. Other properties such as vapor pressure and purity can also be important.

Below is a list of more common shop and household solvents arranged in order of increasing polarity. If a nonpolar one at the top of the list does not work, try one near the bottom and vice versa.

Naphtha, paint thinner, mineral spirits
Toluene, xylenes
Methylene chloride (dichloromethane)
Turpentine (a mixture of many materials)
Methyl ethyl ketone (MEK)
Isopropanol (isopropyl alcohol)
Acetone (finger nail polish remover)
Ethanol (denatured alcohol)
Water
Acids and bases in water (vinegar and ammonia)

Soaps and detergents are both polar and nonpolar. Liquid versions are generally water-based solutions that can contain many other substances.

Solvent paint removers are mixtures of chemicals such as toluene, xylenes and methyl ethyl ketone. They no longer contain methylene chloride. They work by swelling the hardened finish and loosening the bonds to the substrate, e.g. wood.

Most store brand solvents are technical grade and contain impurities so their properties differ from pure solvents.

Please share your experiences with different solvents for various uses such as horror stories about washing your hands with gasoline. :eek:

[Prashun Patel]

Mineral spirits, dna, and water work for most shop situations. Most of the others are better not handled cavalierly.

[Frank Pratt]

I'm going to follow this. I can always use more knowledge of solvents.

When I was an apprentice, one of our old time instructors told stories of when he worked in a transformer plant & at the end of the day they'd wash their hands in pure PCB. :eek:

[Doug Dawson]

I'm going to follow this. I can always use more knowledge of solvents.

When I was an apprentice, one of our old time instructors told stories of when he worked in a transformer plant & at the end of the day they'd wash their hands in pure PCB. :eek:

My brother-in-law who worked for the power company used to brag about doing that very same thing. Unfortunately he died of cancer. As did his wife and all of his children. Very sad.

[Frank Pratt]

My brother-in-law who worked for the power company used to brag about doing that very same thing. Unfortunately he died of cancer. As did his wife and all of his children. Very sad.

Wow, that's awful. I bet a fair bit of that stuff came home with him after work. On his hands, clothes, shoes. My instructor was at least in his mid to late 60's & I have no idea how long he lived. He sure was a good guy.

[Andrew Hughes]

It pretty common for Hot tar roofers to clean up with diesel fuel at the end of the day. I remember seeing the laborers use their bare hands for mastic work. I know of one laborer that was diagnosed with cancer he left the us and went to Mexico for treatment. I remember asking Francisco about him he passed very quickly.

[Mel Fulks]

I think the stuff I use for the urethane caulks is Zylol

[Peter Kelly]

Ethanol (denatured alcohol)"Denatured alcohol" doesn't seem to be regulated and can contain all sorts of toxic nasties beyond just ethanol e.g.: methanol, MEK, MIK, etc. Not good.

Been trying to limit shop solvents to Everclear, Mineral Spirits and Acetone. In San Antonio Texas this coming week so I'll be picking up some 195 proof stuff to try out with the shellac.

[Scott T Smith]

I use d-limonene as a thinner for all of my oil based finishes. It works well and is not a petroleum distillate (it’s citrus based). Sure smells better too. e-bay is the best source that I have found.

[Prashun Patel]

D limonene, contrary to popular belief, is not particularly safe simply by virtue of its citrus source. In concentration, it can be allergenic. In fact, it is required to be labeled when used in consumer cosmetic products in the EU.

Mineral oil and mineral spirits are - in some dimensions - arguably safer than limonene.

Don’t go by unqualified me, but do research it more before trusting it without precaution.

[Jacob Reverb]

...and if you want a nice mix of polar and non-polar solvents (as I do for cleaning metal for tig welding), "lacquer thinner" works well...

What's in it? Depends...;)

My dad used to wash his hands with carbon tet in the old days :eek:

No offense to anyone here, but I think some people go a bit overboard on safety with these things, like my brother's wife who, when she discovered some that pool chlorine had started to get "funny-looking," called in a 10-man, tyvek-clad California hazmat squad to carry it away...you would have thought it was lead-based paint or (gasp) dihydrogen monoxide (https://www.youtube.com/watch?v=yi3erdgVVTw).

[Phil Mueller]

Yes, in my younger days after working on cars I cleaned my hands with gasoline. Back in the day, old oil and gasoline was a good weed killer. And believe it or not, this was done in California.

But to the point of the post, lacquer thinner is my default solvent for removing paint and old finishes on wooden tools/handles. My usual stock is DNA, lacquer thinner, mineral spirits, naptha, and turpentine.

Disposal is my biggest concern. I used to dispose of used solvent by either pouring it out onto cardboard or kitty liter, left to evaporate, then disposed of. Lately, I’ve started mason jars for each solvent, and when they get full, take them to our local recycling center.

[Roger Feeley]

I would add acetone. I use it to clean up epoxy.

[Edwin Santos]

"Denatured alcohol" doesn't seem to be regulated and can contain all sorts of toxic nasties beyond just ethanol e.g.: methanol, MEK, MIK, etc. Not good.

Been trying to limit shop solvents to Everclear, Mineral Spirits and Acetone. In San Antonio Texas this coming week so I'll be picking up some 195 proof stuff to try out with the shellac.

You can substitute 99% Isopropal Alcohol for DA. I used to buy gallon jugs pretty cheap from printing supply houses. You can still do that, but it's also available on Amazon for decent prices. One good benefit is slows down the lightning dry time of Shellac, which will allow it to level a little better IMO.

I recommend always wearing nitrile gloves when handling any solvents or finishes. I go through a lot of them. Lots of ventilation is a good thing too.

[Jim Barstow]

As a former lab organic chemist, I basically bathed in acetone. (We used it for the final rinse of small scale glassware.) It is still my go-to universal solvent. It leaves no residue, evaporates quickly, and is an effective solvent for a wide array of stuff. It is relatively non-toxic and is not carcinogenic. It is naturally produced by metabolic processes so it isn’t a completely foreign substance.

BUT

It is extremely flammable so you have to be careful. Don’t use it in a sink because the vapors can accumulate.

[Jim Becker]

I try to keep a minimum of "solvents" around in my shop...DNA, Mineral Spirits...although I'm now leaning to Naptha to lose the greasiness and Acetone. I also have white vinegar. I really don't need more than that because I use water borne finishes and shellac 99% of the time. As has been noted, any of these solvents (other than the white vinegar) are flammable so care needs to be taken. Mine are stored in a metal cabinet and I always make sure that the containers are sealed before putting them away.

[Mark Daily]

As a former lab organic chemist, I basically bathed in acetone. (We used it for the final rinse of small scale glassware.) It is still my go-to universal solvent. It leaves no residue, evaporates quickly, and is an effective solvent for a wide array of stuff. It is relatively non-toxic and is not carcinogenic. It is naturally produced by metabolic processes so it isn’t a completely foreign substance.

BUT

It is extremely flammable so you have to be careful. Don’t use it in a sink because the vapors can accumulate.
Do you know if mineral spirits leave residue?

[Rick Potter]

I will give you a couple examples. I was a fireman for a large metro department for 34 years.

There was a large structure fire in a phone company building, where it turned out there were numerous transformers which had exploded, and/or leaked. The guys were wading about in water laced with PCB's. Last I heard, almost 20 years ago when I retired...eight of those firemen had died of cancer, and more were suffering.

We had a fire mechanic, one of a dozen, who used to wash parts in diesel fuel because it was easily available. He started to have trouble with his hands swelling by the end of the day. The doctor told him to wear gloves, which he did, but the swelling got worse, and he had to retire early because his hands would react to any grease.

[Prashun Patel]

Good mineral spirits does not leave a residue.

[Zachary Hoyt]

Since the workshop here is inside the envelope of the building we live in I don't use solvents unless water counts. For woodworking I haven't found it necessary, I don't even need mineral spirits except when I'm varnishing canoes which I do outside. My finishing is mostly Tru Oil for instrument work which again I apply outside, or mineral oil/beeswax for food grade jobs. Occasionally I use linseed oil or Danish oil on furniture out of the building, but I put it on with a rag which I let dry and throw away, so no solvents are needed.

[Jeff Clode]

Interesting thread -I don’t want to divert this in another direction but my question is one of fire safety. So far only Jim Becker mentioned keeping solvents in a metal cabinet- is it fire “safe”? What about gasoline for the mower, gas oil mix for the (sigh) snow blower, all the flammable stains, paints, varnishes etc. I know there are standards re this for businesses but what about the average guy in his garage/ shop? Hate to think of what an insurance adjuster might say.....

[Brice Rogers]

I read on the SMC finishing section that DNA was outlawed in California earlier this year.

I periodically use DNA with BLO and shellac. Also, I thin my shellac with DNA as a sealer.

I guess that I'll need to find some substitute like pure isopropyl, everclear, methanol, etc.

[Carl Beckett]

What about gasoline for the mower, gas oil mix for the (sigh) snow blower, all the flammable stains, paints, varnishes etc. I know there are standards re this for businesses but what about the average guy in his garage/ shop?

I do not store gasoline in my attached garage, nor shop. I leave the cans outside, away from the structure by a few feet. I do not put mowers inside for somewhat the same reason, and some of these I switched to electric (in part due to hassles of gasoline, combined with having to clean the carbs all the time due to ethanol/water accumulating and rusting out the bowls.).

Having said that I do have a number of cans of solvents in my shop. 'Most' are in a metal cabinet but not all.... I should rearrange and clean that up.

[Jim Becker]

Interesting thread -I don’t want to divert this in another direction but my question is one of fire safety. So far only Jim Becker mentioned keeping solvents in a metal cabinet- is it fire “safe”? What about gasoline for the mower, gas oil mix for the (sigh) snow blower, all the flammable stains, paints, varnishes etc. I know there are standards re this for businesses but what about the average guy in his garage/ shop? Hate to think of what an insurance adjuster might say.....

My particular cabinet isn't a special "fire retardant" cabinet, although those do exist. There's no gasoline, diesel, etc., in my shop. What little I keep is in the garage bay (separate from the shop, albeit in the same building) where the mower lives during the warm parts of the year and where the tractor lives in the winter so it's accessible if needed.

[Ole Anderson]

The metal cabinet in my shop is an old legal file cabinet with four drawers. Each one can hold four gallon cans of paint or many more quart cans.

Probably not safe, but I keep three 6 gallon plastic gasoline containers in my garage along with many small saws and trimmers, a zero turn mower and two vehicles. Living on the edge baby! My house looks across a canal. 15 years ago my neighbor across the canal pulled her car into the garage to unload groceries, even though it had a gas leak. There is now a new house there. I cringe every time I visit my BIL. Their bedroom is over the garage and there is no firestop drywall on the ceiling above their cars.

[Mark Hockenberg]

Naptha is a miracle solvent when working with laminates and melamine. It does a great job removing contact cement (CC) and glue. I've found that it "balls up" the adhesive rather than smearing it.

I wipe the CC/glue with the wet part of the rag, then as it begins to dry I wipe with the dry part of the rag. This is a very fast cleanup method.

[Mark Daily]

Good mineral spirits does not leave a residue.
Okay, so the inevitable follow-up question- how do you tell good from bad?

[Prashun Patel]

Buy it as "odorless mineral spirits" or "pure mineral spirits".

[Frank Pratt]

Buy it as "odorless mineral spirits" or "pure mineral spirits".

I've heard lots of bad things about the orderless mineral spirits. They're fine for clean up, but not to be trusted as a thinner. Never used them myself though.

[Edwin Santos]

Buy it as "odorless mineral spirits" or "pure mineral spirits".


I've heard lots of bad things about the orderless mineral spirits. They're fine for clean up, but not to be trusted as a thinner. Never used them myself though.

Boy I hope that latter comment is incorrect. I am in the middle of refinishing some plantation teak outdoor chairs with a sludge caviar called Epifanes. I have been using Odorless Mineral Spirits to thin it. Just applied coat #2, haven't really noticed a problem. I wonder if I should be using Naptha instead.

BTW, I always thought of injury in woodworking being an immediate type of thing i.e. cut or kickback. Until this discussion I never considered dying of cancer years later from solvent exposure. So today I started wearing a respirator while applying varnish. Seems to me if the poison can get you through your skin, breathing it in through your lungs is probably not good either. Better to be safe I guess.

[Frank Pratt]

Boy I hope that latter comment is incorrect. I am in the middle of refinishing some plantation teak outdoor chairs with a sludge caviar called Epifanes. I have been using Odorless Mineral Spirits to thin it. Just applied coat #2, haven't really noticed a problem. I wonder if I should be using Naptha instead.

I suppose it depends on the particular formulation. There have been a couple of discussions on other forums and some of the well experienced guys have had bad experiences with it. The paint thinner labeled as 'green' mineral spirits was reported as being problematic as well.

[Carl Beckett]

Oh! I was given a quart of 'mineral oil' a while back. Got it out to use it and it was NOT mineral oil at all. Some type of water based product. Now wish I had a picture of it... I just threw it out, nearly caused me a huge mess. (so much for 'green'! - when it just gets dumped)

[Thomas L Carpenter]

I'm a retired analytical chemist and have used most if not all of the solvents listed above and many more. I'm not too concerned with any of them but that's because i have always avoided excess (whatever that is) exposure to any of them. What is safe today may be considered hazardous many years from now. I keep IPA, mineral spirits, and water in wash bottles on my bench. Carbon tet, chloroform, and benzene were used frequently when I first started in the 60s and 70s and look where they are now.

[Mike Cutler]

I have the usual suspects, as does everyone else. My "favorites" would have to be Acetone and Lacquer thinner. I'm not a 100%, but probably 95%+ always wearing nitril, or latex gloves, handling chemicals. It's usually when I'm working on a car, or garden equipment, that I lapse.
I do keep them in a "Fire Locker". Yep an official one. I got it free because the auto door closure did not work 100% of the time. Not a problem for me, as I open and shut it manually.

Gasoline is not stored in the garage. I keep it stored in Shelter Logic building, out of the sun, and on a cool concrete pad. All of the mowers and such are in there also.

[Andrew Seemann]

I worked for a while in a tape factory in the early 90s. Naturally those of us on the production line got adhesive on ourselves day in and day out. Pretty much everyone washed their hands in MEK at the end of the day, even though it was theoretically against the rules. Nothing else took it off.

Between that, 5 years in a machine shop, and being a gear head and doing my own car and mechanical repairs until I was about 40, I have developed a sensitivity to most petroleum based solvents. For some reason, kerosene and diesel seem to be the worst, but mineral spirits, naphtha, motor oil, and grease irritate my skin as well.

[Mark Daily]

Buy it as "odorless mineral spirits" or "pure mineral spirits".
Ok, thanks. I always use odorless.

[Scott T Smith]

D limonene, contrary to popular belief, is not particularly safe simply by virtue of its citrus source. In concentration, it can be allergenic. In fact, it is required to be labeled when used in consumer cosmetic products in the EU.

Mineral oil and mineral spirits are - in some dimensions - arguably safer than limonene.

Don’t go by unqualified me, but do research it more before trusting it without precaution.

Thanks Prashun for the info; I was unaware of this. Fortunately I don't seem to be allergic to it.

[Jim Barstow]

I chuckle when I talk to someone who thinks that because something is from a natural source it is safer. Forty years ago (probably couldn’t have this situation today), I worked in a university research lab where we had enough tetrodotoxin (isolated from frogs among others) to (theoretically) kill millions of people. (The LD50 is less than 350 MICRO grams / kg much more toxic than cyanide.)

In some cases, a synthetic product may be more pure and safer than the natural product.

[Andrew Seemann]

In some cases, a synthetic product may be more pure and safer than the natural product.

The family biz is a small retail greenhouse, and we always have people coming in wanting organic everything. We try to explain to them that "organic" doesn't mean pesticide-free, it just means that pesticides, if used, have to be certified organic. And some organics (though not most) are nastier than the non-organic ones.

And then there is "organic" fertilizer discussion:) For some reason, many of the organic folks aren't warm to the idea of putting rotted cow sh!t next to their vegetables they are going to eat. Especially after I tell them that back in the 1930s when my great grandfather ran the large greenhouse next door, they would put manure and water in a barrel and let it "season" and then use the liquid that came off it for fertilizer. One of the folks working there accidentally drank some and got typhoid fever from it.

[Jacob Reverb]

I chuckle when I talk to someone who thinks that because something is from a natural source it is safer. Forty years ago (probably couldn’t have this situation today), I worked in a university research lab where we had enough tetrodotoxin (isolated from frogs among others) to (theoretically) kill millions of people. (The LD50 is less than 350 MICRO grams / kg much more toxic than cyanide.)

In some cases, a synthetic product may be more pure and safer than the natural product.

Yeah, I had to laugh when my brother (from California) started spouting about how acetone is harmless because it's produced by the human body.

The human body also produces formaldehyde, as well as something very similar to formaldehyde when it metabolizes ethanol.

[David Utterback]

I learned a lot from your comments on my posting. Several mentioned fire and toxic hazards. Both are very important, obviously, and could be topics for future posts.

My intent was that when using solvents for clean up and general purposes, many similar products will do the job. Yet, when thinning oil based finishes, I follow the label instructions for which solvent.
Their physical properties could affect the way the finish dries and/or hardens. Why chance it. I avoid applying oil-based finishes with brushes so no cleanup waste. I generally apply with a cloth, paper towel or foam brush and discard. Using high grade isopropyl alcohol for shellac sounds good although the odor still reminds me of getting shots when I was a kid.


My total mineral solvent usage is likely less than a quart a year, primarily dna and mineral spirits or naphtha, with maybe 12 events per year. I will break out the lacquer thinner for a particularly tough job. But I do not like using it and my quart container is probably at least 10 years old.

Applying oil based finishes, a likely equivalent exposure risk, would add probably another 2 dozen events. Then add in the solvent -based waxes, cleaners and lubricants, and the number of exposures increases. I really should be more careful about skin contact and inhalation.