Thread: Isopropyl Alcohol 100% or Denatured Alcohol for Shellac?

I also use Diggers metho to dissolve flakes. No issues.

Originally Posted by section1

$20 a litre is expensive just to dissolve shellac and I really don't know how it's viable for Chris to keep using it since he goes through quite a bit of it.
I had to try the Isopropyl otherwise it would have bugged me indefinitely. I will say one thing though, buying the magnetic stirrer on Chris's advice was the best advice. It really does help with dissolving the flakes quickly and completely whether you crush them or not because I have experimented using both methods. A two hour dissolve time is better than a 24hr without the stirrer and with particular matter still left undissolved.

I just went back and read that thread, he said it was $20 a quart and was drinkable.

The thread was started as a concern about using hand sanitizer with methanol in it, if you would like to read it, post #14 has the bit about the Everclear.
Denatured alcohol | The International Association of Penturners

If you really want 100% ethanol it’s available for under 5 bucks a litre if you buy 20L:

Industrial Methylated Spirits (IMS 100) – EnviroChem Online

$6.60/L if you buy 5L.

Originally Posted by section1

Some say that Isopropyl isn't that great for shellac due to it not evaporating as quickly as denatured alcohol. Is this true? This statement totally derives from the yanks and they all make mention of the Isopropyl that's contains 70% isopropyl and 30%water, which in my books shouldn't be used at all. I am wondering though is the 100% or 98.99% Isopropyl just as good as Denatured Alcohol?

Some preparation of rubbing alcohol is 70% isopropyl and 30% water, but rubbing alcohol shouldn't be used. We can buy 99% isopropyl here quite easily. I would agree with you that isopropyl would dissolve shellac more readily than ethanol because of the extra Hydrocarbon chain in its molecular constitution. One can always further dilute the dissolved shellac with 95%+ ethanol, which would allow it to dry more readily.

The reason all ethanol will gravitate towards 95% once opened is that ethanol is hygroscopic until it is 95% proof.

Methanol is not a suitable solvent really, for the opposite reason that isopropyl is. It's best to leave it as a fuel in the racing industry.... It makes your car go fast.

Originally Posted by Ironwood

I just went back and read that thread, he said it was $20 a quart and was drinkable.

The thread was started as a concern about using hand sanitizer with methanol in it, if you would like to read it, post #14 has the bit about the Everclear.
Denatured alcohol | The International Association of Penturners

Hi Brad

'cause we're discussing chemicals it would pay to be a bit more precise with what posters on foreign forums say

Nebraska is one of the 36 states where you can still buy both,
95% Ethanol poisoned with Methanol,
Denatured in the home improvement store for about $5/quart and
95% Ethanol drinkable, Everclear in the grocery store for $20/quart (my punctuation)

now why any sane person would deliberately "poison" ethanol with methanol is beyond me, but we are talking about post-prohibition era Yanks.

Denatured alcohol from the home improvement store will most likely be 95% ethanol plus 5% ethyl acetate to "render the mixture unsuitable for drinking".
Everclear, presumably a brand name, contains 95% ethanol plus water, and as stated is drinkable. Although at $20 per quart, why wouldn't you buy the home center's $6 per quart denatured stuff?

In the EU, ethanol is "denatured" in accordance with the following formula
"Per hectolitre (100 L) of absolute ethanol: add 3 litres of isopropyl alcohol, 3 litres of methyl ethyl ketone and 1 gram denatonium benzoate."
(denatonium benzoate is a really effective bittering agent, with dilutions as low as 10 ppm being unbearably bitter to most humans.)


BTW
the volume of a US quart is about 946 ml -- i.e. about 1.5 US fluid ounces less than a litre.

Originally Posted by ian

I thought Diggers "stove fuel" was actually "white spirit" which is Naphtha.
Though with recent changes in Australia to product sourcing, there is some confusion as to whether "white spirit" is the same as mineral turps (which is sold as "white spirits" in the US) or naphtha (Australian practice) or a benzine based paint thinner.

I have taken a photo of the bottle for the non-believers "Diggers Bio-Flame" & found a copy of the MSDS.

Please note Diggers no longer list it on their website. Why? Now that's a good question as the MSDS for their Metho and Bio-Flame ingredients are identical. Yet the product container for Bio-Flame states "Contains: min 99% ethanol." MSDS are unreliable for "exact" %'s as they state a range & do not list some "proprietary" chemicals.

Chemical Entity CAS Number Proportion (%)
Ethanol 64-17-5 >= 95
Demin. Water 7732-18-5 <= 5

Originally Posted by jack620

If you really want 100% ethanol it’s available for under 5 bucks a litre if you buy 20L:

Industrial Methylated Spirits (IMS 100) – EnviroChem Online

$6.60/L if you buy 5L.

Funny how we all think! Woodturners want 100% IMS yet the cleaners want economy "Is soluble in water and hence can be extended with water to provide economy in cleaning tasks." So why don't the cleaners just use "Metho?"

Originally Posted by justonething

...The reason all ethanol will gravitate towards 95% once opened is that ethanol is hygroscopic until it is 95% proof...

Just to clarify - 95% alcohol by volume (ABV) would be 190 proof, or 95 proof would be 47.5% alcohol by volume. (Using the seppo definition of proof).

The term "proof" came from a 16th century test for purity of alcoholic spirits for taxation purposes. If the spirit would burn, it was deemed to be above proof and taxed at a higher rate. Some tests also used the ability of gunpowder soaked in the spirit to burn as the "proof". These tests defined 100 proof; being about 57% ABV.

The seppos later defined 100 proof as being 50% ABV

Originally Posted by jack620

If you really want 100% ethanol it’s available for under 5 bucks a litre if you buy 20L:

Industrial Methylated Spirits (IMS 100) – EnviroChem Online

$6.60/L if you buy 5L.

If you click on the link. The picture says its 95% Ethanol Solution. Same as Diggers Methylated spirit.

99% Ethanol at $4/litre:

Ethanol 5 Litre | Denatured Alcohol | Sydney Solvents

Originally Posted by justonething

The picture says its 95% Ethanol Solution.

So it does. I’ll give them the benefit of the doubt and assume they’ve used the wrong photo, as they also sell IMS95. I’ll check though.

Originally Posted by RossM

99% Ethanol at $4/litre

$8 per litre by my calculations.

Metholated spirit can leave an oily type of residue on glass which can be quite difficult to remove

Are you sure it’s metho?
We used metho to do a final clean on brake hydraulic components because it DOES NOT leave a film.