Classical Build (s) - Hopefully falcate!

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mooshalah
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Re: Classical Build (s) - Hopefully falcate!

Post by mooshalah » Sat May 23, 2020 5:48 am

Hello folks.

I'm probably going to be shot down for this long and complicated post, but that's OK, if perhaps even a small part of what follows might be useful to someone. Perhaps I should post it elsewhere.

I'll preface what follows with the statement that I have spent my previous long working life as an Industrial Chemist / Chemical Engineer and have sometimes managed large laboratories, so I know a little whereof I now will speak!

"Alcohol" is just a word that, scientifically, is used to describe a particular chemical structure. There are literally thousands of alcohols - all different, but with this (rather simple) organic chemical structure that contains as one of its parts, an -OH structure (oxygen-hydrogen bonded together). The suffix "-ol" in chemistry always describes an alcohol. So, ethanol, methanol, propanol, isobutanol, sorbitol, menthol etc.

Ethyl alcohol (also known as ethanol, but for hundreds of years as "spirits") is the stuff that people drink the world over. It's in every "alcoholic" drink known on earth. It's not poisonous as such - although it makes you drunk, and will even kill you, if you drink too much!

Ethanol is produced on an amazingly vast scale, all over the world - and not by having to distil beer and wine. It is one of the most common (and cheap) solvents required by global industry. As you'll imagine, governments don't want people to just go and buy pure ethanol and drink it. It honestly costs much, much less than a dollar per litre to produce, and so it would in fact be the cheapest way to get drunk - and all governments want the heavy taxes that they impose on alcoholic drinks, and it's not desirable to have large swathes of the population staggering around drunk on cheap alcohol!

So earlier governments required that ethanol producers (that is, industrial scale producers) "denature" the ethanol by adding methyl alcohol (methanol) to it, to inhibit people from drinking the stuff. Methanol is in fact a known poison, deliberately added so that if you drink it you'll get sick (and if you drink pure methanol you can become blind, and you'll certainly die if you ingest too much!)

Over time, as public safety concerns have changed, so have formulations. It is still permitted to sell Metho in Australia with up to 5% methanol added to it, but suppliers are also permitted to substitute it with chemicals to make the stuff taste bitter, smell bad, and colour it (often purple or blue). For example denatonium benzoate, an extremely foul-tasting bitter material colloquially called a "bitterant" might be added at a level of around 0.1 - 0.2%, either to substitute for, or in addition to methanol.

The problem is that "Metho" is now the generic Australian word for "ethyl alcohol with some stuff added to it to make it undrinkable". In America the expression "denatured alcohol" means the same thing. It doesn't necessarily fully describe the ingredients of any particular bottle.

So, Metho may or may not contain methanol. For example, here in Australia, Diggers brand of "Methylated Spirits" that you buy in Bunnings contains no methanol, while the Recochem brand, also sold in Australia as "Special Methylated Spirits" contains 5% methanol.

Methanol is very closely chemically related to ethanol, so that if it is added to the ethanol, it doesn't change the solvent properties of the material in any meaningful way. Thus, it's usually pointless and expensive to try and buy "pure ethanol" for this purpose (acting as a solvent).

I can't speak authoritatively about which stuff to buy (ethanol with or without 5% methanol) for French polishing, - although I do some of this - but strongly suspect that it makes no difference (and you're welcome to disagree with me!) The presence of water in the Metho might however be worth some discussion.

The commercial production of ethanol yields a material that is 95% ethanol and 5% water. This is not because the producers are sloppy, or want it this way. Rather, commercially, ethanol is produced via a final distillation step, and the purest that one can obtain ethanol by this process is 95% pure. The matter has to do with the formation of what are called chemical azeotropes.

During the process of distillation, 5% of water "clings" to the alcohol during the boiling and condensing process. To get the last 5% of water out of the ethanol, a second (more expensive) process, using sodium metal is required - and for the purposes of it being an industrial solvent, this 5% of water is not an issue.

Likewise, methyl alcohol and bittering agents will not separate from ethanol during distillation, so you can't simply boil up then condense Metho for a cheap drink!

Any cheap ethanol you buy as Metho (or Methylated Spirits, or Denatured Alcohol) will have this 5% water still in it (and if it has in addition an added 5% of methanol, it will thus be only 90% ethanol), and this could just arguably be an issue in French polishing, given that shellac is completely insoluble in water. Again, I don't see this, but others who will know much more about this subject might wish to correct me.

Finally, just to complete the picture, Analytical laboratories require pure ethanol which can be bought from laboratory chemical suppliers - but the Australian government loads such product with a huge tax, so that it's prohibitively expensive. If you have a commercial laboratory and MUST have pure ethanol, you can apply for an exemption from the taxes - but this is a complicated matter, requiring the keeping of careful records that governments periodically inspect - and if you can't account for virtually every drop, the tax is ruthlessly, retrospectively applied.

Cosmetics manufacturers that use ethanol in their formulations that may be applied to the skin have their own set of hurdles to jump.

As a chemist, I constantly rage against the common, inaccurate terms applied to chemicals. For example, methanol is often also called "wood spirit" and chemically (more correctly) as "methyl hydrate". And don't get me started on "rubbing alcohol" aka "surgical spirit" which is usually a 70% isopropanol / 30% water mixture, but the term is increasingly being misused in this age of Covid-19 hand sanitisers.

Thus endeth the sermon.

Frank.

johnparchem
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Re: Classical Build (s) - Hopefully falcate!

Post by johnparchem » Sat May 23, 2020 6:29 am

mooshalah wrote:
Sat May 23, 2020 5:48 am
Hello folks.

I'm probably going to be shot down for this long and complicated post, but that's OK, if perhaps even a small part of what follows might be useful to someone. Perhaps I should post it elsewhere.

I'll preface what follows with the statement that I have spent my previous long working life as an Industrial Chemist / Chemical Engineer and have sometimes managed large laboratories, so I know a little whereof I now will speak!

"Alcohol" is just a word that, scientifically, is used to describe a particular chemical structure. There are literally thousands of alcohols - all different, but with this (rather simple) organic chemical structure that contains as one of its parts, an -OH structure (oxygen-hydrogen bonded together). The suffix "-ol" in chemistry always describes an alcohol. So, ethanol, methanol, propanol, isobutanol, sorbitol, menthol etc.

Ethyl alcohol (also known as ethanol, but for hundreds of years as "spirits") is the stuff that people drink the world over. It's in every "alcoholic" drink known on earth. It's not poisonous as such - although it makes you drunk, and will even kill you, if you drink too much!

Ethanol is produced on an amazingly vast scale, all over the world - and not by having to distil beer and wine. It is one of the most common (and cheap) solvents required by global industry. As you'll imagine, governments don't want people to just go and buy pure ethanol and drink it. It honestly costs much, much less than a dollar per litre to produce, and so it would in fact be the cheapest way to get drunk - and all governments want the heavy taxes that they impose on alcoholic drinks, and it's not desirable to have large swathes of the population staggering around drunk on cheap alcohol!

So earlier governments required that ethanol producers (that is, industrial scale producers) "denature" the ethanol by adding methyl alcohol (methanol) to it, to inhibit people from drinking the stuff. Methanol is in fact a known poison, deliberately added so that if you drink it you'll get sick (and if you drink pure methanol you can become blind, and you'll certainly die if you ingest too much!)

Over time, as public safety concerns have changed, so have formulations. It is still permitted to sell Metho in Australia with up to 5% methanol added to it, but suppliers are also permitted to substitute it with chemicals to make the stuff taste bitter, smell bad, and colour it (often purple or blue). For example denatonium benzoate, an extremely foul-tasting bitter material colloquially called a "bitterant" might be added at a level of around 0.1 - 0.2%, either to substitute for, or in addition to methanol.

The problem is that "Metho" is now the generic Australian word for "ethyl alcohol with some stuff added to it to make it undrinkable". In America the expression "denatured alcohol" means the same thing. It doesn't necessarily fully describe the ingredients of any particular bottle.

So, Metho may or may not contain methanol. For example, here in Australia, Diggers brand of "Methylated Spirits" that you buy in Bunnings contains no methanol, while the Recochem brand, also sold in Australia as "Special Methylated Spirits" contains 5% methanol.

Methanol is very closely chemically related to ethanol, so that if it is added to the ethanol, it doesn't change the solvent properties of the material in any meaningful way. Thus, it's usually pointless and expensive to try and buy "pure ethanol" for this purpose (acting as a solvent).

I can't speak authoritatively about which stuff to buy (ethanol with or without 5% methanol) for French polishing, - although I do some of this - but strongly suspect that it makes no difference (and you're welcome to disagree with me!) The presence of water in the Metho might however be worth some discussion.

The commercial production of ethanol yields a material that is 95% ethanol and 5% water. This is not because the producers are sloppy, or want it this way. Rather, commercially, ethanol is produced via a final distillation step, and the purest that one can obtain ethanol by this process is 95% pure. The matter has to do with the formation of what are called chemical azeotropes.

During the process of distillation, 5% of water "clings" to the alcohol during the boiling and condensing process. To get the last 5% of water out of the ethanol, a second (more expensive) process, using sodium metal is required - and for the purposes of it being an industrial solvent, this 5% of water is not an issue.

Likewise, methyl alcohol and bittering agents will not separate from ethanol during distillation, so you can't simply boil up then condense Metho for a cheap drink!

Any cheap ethanol you buy as Metho (or Methylated Spirits, or Denatured Alcohol) will have this 5% water still in it (and if it has in addition an added 5% of methanol, it will thus be only 90% ethanol), and this could just arguably be an issue in French polishing, given that shellac is completely insoluble in water. Again, I don't see this, but others who will know much more about this subject might wish to correct me.

Finally, just to complete the picture, Analytical laboratories require pure ethanol which can be bought from laboratory chemical suppliers - but the Australian government loads such product with a huge tax, so that it's prohibitively expensive. If you have a commercial laboratory and MUST have pure ethanol, you can apply for an exemption from the taxes - but this is a complicated matter, requiring the keeping of careful records that governments periodically inspect - and if you can't account for virtually every drop, the tax is ruthlessly, retrospectively applied.

Cosmetics manufacturers that use ethanol in their formulations that may be applied to the skin have their own set of hurdles to jump.

As a chemist, I constantly rage against the common, inaccurate terms applied to chemicals. For example, methanol is often also called "wood spirit" and chemically (more correctly) as "methyl hydrate". And don't get me started on "rubbing alcohol" aka "surgical spirit" which is usually a 70% isopropanol / 30% water mixture, but the term is increasingly being misused in this age of Covid-19 hand sanitisers.

Thus endeth the sermon.

Frank.
With all of that I think I was right in suggesting care with a can of something called methanol.

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kiwigeo
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Re: Classical Build (s) - Hopefully falcate!

Post by kiwigeo » Sat May 23, 2020 9:54 am

This is the stuff I use.....I used to get it from a retail outlet here in Adelaide and I think Robert Shines still supplies the stuff. http://www.recochem.com.au/index.php/pr ... industrial

Robert is best contacted via phone call....he's very knowledgeable and helpful. http://shines.com.au/
Martin

seeaxe
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Re: Classical Build (s) - Hopefully falcate!

Post by seeaxe » Sat May 23, 2020 10:54 am

Like most things in life things are often more complicated than they seem as first. So thanks @mooshalah all useful stuff.

I actually purchased some ethanol (it was pretty hard to track down) but have a big tin of this stuff whatever it actually is to use up so that's what I am doing. So far so good as far as i know.

Thanks for all the inputs everyone.
Richard

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56nortondomy
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Re: Classical Build (s) - Hopefully falcate!

Post by 56nortondomy » Sat May 23, 2020 6:05 pm

I've bought 100% methylated spirits for FP from paint spot. Not all the paint spot stores sell it.
Wayne

seeaxe
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Re: Classical Build (s) - Hopefully falcate!

Post by seeaxe » Sun Jul 05, 2020 4:28 pm

Well if you thought the FP spirit was bad you should read the MSDS for the Mirotone. 25 pages. First two pages told me i dont have the correct PPE or ventilation and the other 23 set consequences of using the stuff. Holy crap.

Given im doing this in my garage i would be wafting clouds of this stuff all over the neighbours. Not to mention my son in law.

So the Mirotone is going back and I'm FPing the whole thing. Its probably going to cost me money but that was one of those decisions i knew was right. RTFM...before you buy the stuff.

Anyhoo onwards and upwards.
IMG-20200705-WA0000.jpeg
IMG-20200705-WA0004.jpeg
Richard

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