Replies

1. 
   saschafer | Jun 23, 2008 05:38pm | #1

   Yes. Strictly speaking, "paint thinner" is a rather generic term, but if you buy a can labeled "paint thinner" at the store, it will be equivalent to mineral spirits. You should try to get so-called "odorless" mineral spirits or paint thinner, which has had most of the aromatic compounds removed. This makes the thinner/spirits less harmful to your health.

   Another synonym for mineral spirits is Stoddard solvent.

   -Steve

    

1. 
   flairwoodworks | Jun 30, 2008 12:34am | #4

   Steve,

   So you're saying that it's the chemicals that smell that are harmful, not the ones that don't smell?  I thought (based on nothing) that it was like natural gas where a smell is added so that we can detect its presence.Chris @ http://www.flairwoodwork.spaces.live.com

    - Success is not the key to happines.  Happiness is the key to success.  If you love what you are doing, you will be successful. - Albert Schweitzer

1. 
   saschafer | Jun 30, 2008 01:29am | #5

   "So you're saying that it's the chemicals that smell that are harmful, not the ones that don't smell?"

   Not exactly. The ones that have a strong smell are, in general, more harmful than the ones that don't, but that's not to say that the less smelly ones are harmless. Broadly speaking, the hydrocarbons in paint thinner and other solvents woodworkers are likely to encounter can be classified as aliphatic or aromatic. Aromatic hydrocarbons contain benzene rings; aliphatic hydrocarbons are everything else (well, not quite, but close enough). Aromatic hydrocarbons tend to have stronger and often fairly pleasant smells (hence the name, "aromatic") and they tend to be more physiologically reactive, which increases the likelihood of their being harmful. However, that isn't a hard and fast rule.

   "I thought (based on nothing) that it was like natural gas where a smell is added so that we can detect its presence."

   The compounds added to methane, propane, etc. are generally sulfur-based compounds known as mercaptans or thiols, and are extremely smelly--only a tiny amount is added to produce the distinctive smell. Most aromatic compounds are nowhere near as odoriferous.

   -Steve

    

1. 
   pzaxtl | Jul 01, 2008 06:32am | #6

   Periodically, I'll have a problem with aromatic hydrocarbons.  Now, I really don't mind the smell, but my wife sure does!  Mind you, this doesn't happen all the time, only every now and then, depending on what I eat.

1. 
   davcefai | Jul 05, 2008 01:27pm | #11

   "
   Periodically, I'll have a problem with aromatic hydrocarbons. Now, I really don't mind the smell, but my wife sure does! Mind you, this doesn't happen all the time, only every now and then, depending on what I eat.
   "Precisely! I believe that this is the same phenomenon whereby beer can taste wonderful before a meal but not after it.As far as your wife goes, join the club. Personally I am more or less immune having smelled a lot of organics over the past 35 years. However the "smell test" is a useful one. Treat all volatile solvents with caution. Apart from the aromatics (containg benzene rings) things like ketones don't do the liver any good.

2. 
   woodchuckwood | Jul 05, 2008 04:44am | #7

   "So you're saying that it's the chemicals that smell that are harmful, not the ones that don't smell?"

   Chris,

   I would not every use smell as a indicator if a particular chemical is harmful.  Chloroform is carcenogenic and doesn't smell as much as diethylether.  Try not to smell any of the chemicals we might use.

   mineral spirits feels oily because as stated before, has heavier petrolem distallates and thus has a lower vapor pressure ie boiling point.

    

   Children are our future, unless we stop them now -- Homer Simpson

   Edited 7/4/2008 9:49 pm ET by woodchuckwood

1. 
   brucet9 | Jul 08, 2008 03:51am | #14

   "mineral spirits feels oily because as stated before, has heavier petrolem distallates and thus has a lower vapor pressure ie boiling point."I'm sure you must have meant to say lower vapor pressure and HIGHER boiling point. Those two properties of a liquid are inverse to one another.Mineral spirits is defined as having a flash point (temperature at which enough vapor exists above the surface of a liquid that a spark or flame can ignite it.) above 100°F but lower than 140°F.140 Flash solvent is oilier and flashes at over 140°F.VM&P Naphtha is similar in solubility and odor to the above two, but dries much faster, has no oily feel to it and flashes at something like 65°F, making it much more hazardous to work with.BruceT

2. 
   woodchuckwood | Jul 09, 2008 07:16pm | #20

   your right,

   I'll stick to drug chemistry and let you petro guys answer the solvent questions ;-)

    Children are our future, unless we stop them now -- Homer Simpson

3. 
   woodchuckwood | Jul 05, 2008 04:47am | #8

   Steve,

   good information.  do you know what the following chemical formula represents? BaNa2?

   Are you a chemist Steve?

   DaveChildren are our future, unless we stop them now -- Homer Simpson

1. 
   saschafer | Jul 05, 2008 04:58am | #9

   1) Musa acuminata

   2) Physicist/engineer

   -Steve

2. 
   xmike | Jul 05, 2008 05:17am | #10

   According to Google, BaNa2 is respectively..
   - a joke that only chemists understand (there are web sites devoted to such fare)
   - a small banana (musa acuminata)
   - an obscure band currently enjoying U-Tube popularity
   :)Edited 7/4/2008 10:19 pm ET by Mike_D

   Edited 7/4/2008 10:21 pm ET by Mike_D

3. 
   woodchuckwood | Jul 06, 2008 04:33pm | #12

   nobody said chemistry humor was that great, and google ruins everything

    Children are our future, unless we stop them now -- Homer Simpson

4. 
   xmike | Jul 06, 2008 06:34pm | #13

   nuh-uh!
   :)

2. 
   dkellernc | Jun 23, 2008 05:43pm | #2

   Not exactly.  "Mineral Spirits" is a generic name for a mixture of aliphatic hydrocarbons that fall into a fairly narrow range of boiling points.  This range is higher than that for laquer thinner, so mineral spirits are less volatile (i.e., the vapor pressure of mineral spirits is lower at room temp) and is similar to kerosene and deisel fuel.

   There are various purity levels of mineral spirits, with the highest, most refined grade being "low odor mineral spirits", and the cruder mixtures often labeled as "paint thinner".  These lesser grades typically contain some aromatic (i.e., possessing a benzene ring in their structure) hydrocarbons that give it a characteristic odor.

   From the standpoint of use, you can clean a brush that contains polyurethane or an oil-based varnish with either product, it's just more expensive to use the low-odor mineral spirits.  For thining oil-based paint or polyurethane, it's usually better to use the higher grade stuff - some of the impurities in paint thinner can interfere with the solubility of the pigments in paint or the catalysts in polyurethane, causing clumping or interfering with polymerization (hardening).

1. 
   brucet9 | Jul 08, 2008 04:13am | #16

   "...some of the impurities in paint thinner can interfere with the solubility of the pigments in paint or the catalysts in polyurethane, causing clumping or interfering with polymerization (hardening)."If by impurities you mean entrapped water, then you may be right. If you mean aromatics, the above statements aren't true. Pigments aren't "dissolved" in paint, they are solid particles suspended in the resin, so no amount of any solvent impurities can affect the pigments.Polyurethane "catalysts" will not react with aromatic hydrocarbons. Those catalysts are looking for specific parts of resin molecules to react with to make a cross-linked polymer. Water, on the other hand can cause all sorts of problems as can some alcohols.
   BruceT

1. 
   dkellernc | Jul 08, 2008 06:38pm | #17

   That's not quite true.  Remember that aromatics is a pretty broad term - there are aromatics that are purely carbon and hydrogen (like benzene) and those that are polynuclear aromatics, like pyridine, phenols, etc...  Aromatics with nucleophilic (and potentially, electrophilic) reaction sites can easily interfere with polymerization agents.

   You're correct about pigments, of course - they're not truly solubilized.  That said, their ability to stay suspended is greatly affected by their surface polarization and the polarization and/or protonation of the solvent.  Moreover, thinning one of these suspended solids mixtures with a solvent that has a significantly different degree of polarity or protonation can promote aggregation of the solids, which can lead to faster settling.   

   For a woodworking forum "solubility" is just an easier to understand generalization. ;-)

1. 
   brucet9 | Jul 09, 2008 08:11am | #18

   "...polynuclear aromatics, like pyridine, phenols, etc."I thought that such chemicals had to be purposely made. Do they occur naturally in petroleum feed stocks? In all my years in the petrochemical industry I never encountered solvents that smelled like they might have contained such stuff. A few times we got a load with trace amounts of mercaptans, but nothing that a little vanillin wouldn't alleviate. BruceT

1. 
   dkellernc | Jul 09, 2008 05:20pm | #19

   Yeah, they do.  Most of the PAHs (polynuclear aromatic hydrocarbons) occur naturally as contaminants to crude oil, and are removed in the refining process.  Depending on what grade of product is produced, the PAHs may only be barely detectable, or may be significant contaminants.

   As an aside, coal is really full of PAHs, so one wonders what gasoline and deisel fuel made from it is going be like (and they're a ton of operations starting up to liquify coal into fuel  - assuming that oil stays above $100/barrell)

3. 
   PCM | Jun 30, 2008 12:00am | #3

   I will leave the scientific stuff  to people who have a lot more knowledge than I do. What I do know is this: "paint thinner" will leave a lot more "oil" in the wood-you can feel the difference on your hands! I look for "100% mineral spirits" at the store, not a product that "contains mineral spirits".

   Is there a specific criteria for mineral spirits? Probably not, especially since the Big Boxes" are charging $8.50-$9.50 per gallon (up from $1.87 a few years ago).

   On the same note, "lacquer thinner" is whatever the manufacturers want to put in it, "denatured alcohol" probably has ketones, strippers are getting weaker and weaker to meet EPA or whoever requirements.

   Who can you trust anymore?

   Have a great day!

   Pete

4. 
   brucet9 | Jul 08, 2008 04:05am | #15

   Other posters have suggested that lower odor products are better quality, which is not necessarily so.

   Low odor mineral spirits is made from purely aliphatic feed stock which has little odor, but which also has less solvency power.

   Ordinary mineral spirits contains some aromatics and/or napthenes, which are smellier than aliphatics but significantly stronger solvents.

   So low odor is pleasanter to use but not as strong. You will have to dilute the material more to get the same working viscosity and that means that dry time will be longer.

   BruceT