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Building Tips and technical articles. => Paint and finishing => Topic started by: Larry Renger on September 24, 2024, 07:27:01 PM

Title: Denatured alcohol
Post by: Larry Renger on September 24, 2024, 07:27:01 PM
It seems this mild solvent is now banned in California. Anyone know why? Acetone and others are still available. ⁉️
Title: Re: Denatured alcohol
Post by: Dave Hull on September 25, 2024, 01:46:30 AM
Larry,

From what I can read, it doesn't make a lot of sense. It seems the legislation on this goes back to 2010. I'm not sure of the implementation date. The idea was that the VOCs from denatured alcohol were thought to damage the atmosphere, and probably that it was an "easy" target. It starts to sound foolish if you were using acetone as the denaturing solvent and you can still buy acetone. But acetone is not an easy target due to all of its uses and no substitutes. Or so perhaps someone judged.

I prefer denatured alcohol as the solvent for a shellac finish on my furniture projects, when shellac is suitable. Bummer. Now I might have to resort to using some Golden Grain 190...?

Dave
Title: Re: Denatured alcohol
Post by: Steve Dwyer on September 25, 2024, 05:10:36 AM
Looks like it's right up there with the growing unavailability of Naphtha, another mild solvent.
Title: Re: Denatured alcohol
Post by: bill bischoff on September 25, 2024, 02:34:02 PM
I was trying to find out what the actual composition of denatured alcohol a while ago. What I learned by looking at various MSDS info is that most denatured alcohol these days is essentially an equal mix of methanol and ethanol. I also learned that denatured alcohol started out as ethanol that was "contaminated" with other chemicals to make it unfit for drinking. Compared to "beverage" alcohol, with its associated taxes and fees, "solvent" alcohol was much less expensive, and they didn't want people to drink it because it was cheaper. All that being said, I would think that straight methanol would be an acceptable substitute in most cases. Just my $.02.
Title: Re: Denatured alcohol
Post by: Dave Hull on September 25, 2024, 03:12:03 PM
Bill,

Thanks for the research. I may have to resort to methanol for any future shellac work. Some report that it works. I just haven't had the need since I repaired a couple of antique rocking chairs a couple of years ago. It is going to take a test panel for sure, but I still won't know what it might do over time. I find it interesting that the denatured alcohol I previously bought had a soft, almost oily feel to it. Methanol feels totally different.

I haven't seen naphtha in the store for a while either....
Title: Re: Denatured alcohol
Post by: Dan McEntee on September 25, 2024, 03:47:17 PM
I was trying to find out what the actual composition of denatured alcohol a while ago. What I learned by looking at various MSDS info is that most denatured alcohol these days is essentially an equal mix of methanol and ethanol. I also learned that denatured alcohol started out as ethanol that was "contaminated" with other chemicals to make it unfit for drinking. Compared to "beverage" alcohol, with its associated taxes and fees, "solvent" alcohol was much less expensive, and they didn't want people to drink it because it was cheaper. All that being said, I would think that straight methanol would be an acceptable substitute in most cases. Just my $.02.

   Back in my 8 track tape player days, the heads needed to be cleaned frequently and I was told to use denatured alcohol. I asked a pharmacist what that was and if it was the same as isopropyl alcohol and he just said it was "alcohol with no water content in it." I'm still not sure what it is!! If methanol will do the same job, and you just need small amounts, the gas line antifreeze "HEET" is pure methanol, says so right on the bottle. Gary Frost once told me he tried mixing model fuel using HEET and it actually worked!!
   Type at you later,
    Dan McEntee
Title: Re: Denatured alcohol
Post by: Dave Hull on September 25, 2024, 11:26:44 PM
If that is what the pharmacist told you--at best it was misleading and more likely it was wrong! The three commonly known alcohols all have different chemical compositions. The number of carbon atoms in the molecule are all different. Ethanol is not very poisonous, whereas Methanol and Isopropyl are very poisonous. Things seem to get more confused when you hear people say that isopropyl alcohol is "the same thing" but just has water in it. Not true. Even without added water (which makes it "rubbing alcohol") it is chemically not the same as either methanol or ethanol. They are used for different purposes because they are different. For example, the combustion speed of methanol is faster than ethanol. The heat of combustion of ethanol is roughly double that of methanol. Etc.

So for painting and finishing, it would be safer to use ethanol than methanol. And the vaporization temperature should be safer, too. But apparently, someone decided it was the more dangerous VOC.
Title: Re: Denatured alcohol
Post by: spare_parts on September 26, 2024, 07:30:45 AM
Check the SDS if it really matters. Some I've looked at were indeed 50/50 ethyl/methyl, others 95/5 some had ketones with or without methyl. Others were mainly isopropyl.
Title: Re: Denatured alcohol
Post by: Paul Smith on September 26, 2024, 07:44:26 AM
Methanol is wood alcohol, made from wood, good for fuel and poisonous to drink.
Wood farmers don't have much pull in Washington DC.

Ethanol is grain alcohol, made from corn or potatoes.  Good to drink and good for fuel.
When  used as fuel it is government subsidized.
When used to drink it is HEAVILY taxed.
Corn farmers are in every state and thus corn alcohol (when poisoned by gasoline) is heavily subsidized.
Ironically, I have bought gasoline in Iowa and Nebraska and noted that alcohol-free gasoline is offered at a premium price.

Denatured alcohol is poisoned ethanol to keep people from drinking to avoid taxation.
I don't know exactly what the poison is, but I sure don't drink the stuff.
Home Depot sells to labeled as "Fuel".
It works well for clearing models that have been flown with glow fuel and for cleaning engines and parts.

Incidentally, the V2 ballistic rocket was fueled with potato ethanol (vodka) and it worked well enough.
Title: Re: Denatured alcohol
Post by: Dennis Toth on October 13, 2024, 09:17:26 AM
Paul,
Denatured alcohol is usually a mix of grain alcohol and methanol and would actually work fine as a base for sport fuel in glow engines.

Best,   DennisT
Title: Re: Denatured alcohol
Post by: john e. holliday on October 13, 2024, 03:15:00 PM
It has to be because some politician is trying to make a name for him/her self.    D>K
Title: Re: Denatured alcohol
Post by: Brett Buck on October 13, 2024, 05:40:46 PM
It has to be because some politician is trying to make a name for him/her self.    D>K

  VOC and the California Air Resources Board (CARB).

     Brett
Title: Re: Denatured alcohol
Post by: wwwarbird on October 13, 2024, 08:11:04 PM
It seems this mild solvent is now banned in California. Anyone know why?

 Because it's California, they've got everything figured out, just ask Kamala.  LL~
Title: Re: Denatured alcohol
Post by: Dave Moritz on October 14, 2024, 12:07:09 PM
Paul

Just to summarize your origins of the three alcohol types:
Methanol = wood
Ethanol = grains
Isopropyl = propane + some complicated chemistry

Dave Mo…
Title: Re: Denatured alcohol
Post by: Howard Rush on November 13, 2024, 12:37:50 AM
Methanol
Ethanol
Isopropyl

One, two, and three carbons, respectfully.

I was applying a decal thing to a stunt plane once and needed some ethanol for the process.  I went to a liquor store.  They wouldn't sell me the straight stuff, so I bought some 151-proof rum, which did the job.  I still have the rest of it if anybody needs it for anything.
Title: Re: Denatured alcohol
Post by: Paul Smith on November 13, 2024, 06:53:50 AM
Everclear, the 198 proof alcohol, was available at liquor stores at military bases, even in "dry" states.
Maybe somebody still on active duty could verify if this is still true.
It was also the fuel for the successful V2 ballistic rocket.
Title: Re: Denatured alcohol
Post by: Larry Renger on November 13, 2024, 09:08:23 AM
One, two, and three carbons, respectfully.

I was applying a decal thing to a stunt plane once and needed some ethanol for the process.  I went to a liquor store.  They wouldn't sell me the straight stuff, so I bought some 151-proof rum, which did the job.  I still have the rest of it if anybody needs it for anything.

Got some Coke? It will dilute it enough to be drinkable. 😁
Title: Re: Denatured alcohol
Post by: spare_parts on November 13, 2024, 12:54:32 PM
Just to summarize your origins of the three alcohol types:
Methanol = wood
Ethanol = grains
Isopropyl = propane + some complicated chemistry

Dave Mo…

Methanol is made from natural gas these days.