20 replies to this topic

[Strobe]

I'm curious what the differences are between the various Alcohols used in pyrotechnics. I'm aware of:
Ethyl,
isopropyl,
methyl,
denatured

Is there any reason to use one above another? Most recipes I see just refer to the generic term Alcohol versus specifying a particular type.

Isopropyl and denatured alcohol (though I am not clear what denatured alcohol is comprised of) seem readily available. I'm not real clear on where methyl or ethyl alcohol can be obtained cheaply. I imagine you can buy products like "Everclear' at a liquor store (for ethyl) but I'd guess it might be expensive relative to other available products due to it being a beverage.

[starseeker]

I'm curious what the differences are between the various Alcohols used in pyrotechnics. I'm aware of:
Ethyl,
isopropyl,
methyl,
denatured

Is there any reason to use one above another? Most recipes I see just refer to the generic term Alcohol versus specifying a particular type.

Isopropyl and denatured alcohol (though I am not clear what denatured alcohol is comprised of) seem readily available. I'm not real clear on where methyl or ethyl alcohol can be obtained cheaply. I imagine you can buy products like "Everclear' at a liquor store (for ethyl) but I'd guess it might be expensive relative to other available products due to it being a beverage.

Hi Strobe,
methyl alcohol is available as methylated spirits in any hardware store,
regards,
Vince.

[treefingers]

Methylated spirits is actually the same as denatured alcohol and is usually ethanol (90%) with an additive to make it undrinkable. It is called methylated because originally the additive was methanol but quite often nowadays other substances are used i.e. isopropyl alcohol or avaiation gasoline.

[Strobe]

Thanks for the info on Denatured/Methylated alcohol.

Does it matter which you use, when alcohol based solvents are called for? Or do people just use the cheapest available. I'm guessing this is going to be denatured followed by isopropyl.

Treefinger's comment about the possibility of different additives makes me wonder if there isnt the potential for problems using denatured. Would Aviation gas be a bad thing for pyrotechnic compositions?

Thanks

-Strobe

[seymour]

If you are adding it to water, then it's primary use is to break the surface tension, and all will work. As a solvent, all comps saying "bind with binder x and alcohol" should work with the common alcohols. So, you should be able to use all of them.

Edited by seymour, 27 February 2007 - 11:24 AM.

[TCblastmaster]

While different types of alcohol can be useful in terms of their ability to reduce the surface tension of water, particularly when rolling stars of compositions prone to spiking, each type has a different boiling point and vapour pressure.

These factors become important with regard to drying times of stars, etc., and of course if making BP using the precipitaton method as an alcohol with a low boiling point is necessary for it to rapidly evaporate, therefore extracting heat from the mixture to bring the KNO3 out of solution in the form of minute crystals.
Do not forget that the vapour is extremely flammable and toxic. Methyl alcohol is also directly toxic to the Optic nerve and inhalation of vapour can lead to blindness.

The alcohols mentioned are similar chemically, but isopropyl alcohol has a lower vapour pressure and therefore stars made with it take slightly longer to dry, which is useful for preventing the problem of the surface layers of stars drying and forming a barrier to further evaporation. So called 'driven-in' stars refuse to dry.

TC

[BigG]

Thanks for the info on Denatured/Methylated alcohol.

Does it matter which you use, when alcohol based solvents are called for? Or do people just use the cheapest available. I'm guessing this is going to be denatured followed by isopropyl.

Treefinger's comment about the possibility of different additives makes me wonder if there isnt the potential for problems using denatured. Would Aviation gas be a bad thing for pyrotechnic compositions?

Thanks

-Strobe

All of the mentioned once are serviceable. Ethanol (98%) is a preferred choice with many pyrotechnics. It’s a good solvent – that does not smell like it’s about to kill you and has a fast drying time. It’s hard to obtain in the UK (not to mention expensive), as pharmacies apparently cannot sell it (I heard that as it is drinkable – they will need to hold a alcoholic drink license for it… that’s just stupid – but I can think of a few people who will do just that). Also tax is levied because it is drinkable. For factories it’s less of a problem – large quantities can still be obtained for good prices.

Methylated is okay to use – but I find the vapours to give you one solid headache. They just hang around forever long after you finished your work. I can’t imagine allot of factories that can take the smell for long. Also, there are now three published works that connect between Methylated products and eye damage. The researches are done on people who work with those materials is regular bases – so probably will concern those here that are factory manufacturers, but it is something to bare in mind.

Isopropyl in my personal opinion is the best all around choice for the hobbyist. It’s widely available – light on smell, and has no risks associated with it. It is very similar in behaviour to ethanol – although drying times are longer.

Hope that helps.

[Strobe]

All of the mentioned once are serviceable. Ethanol (98%) is a preferred choice with many pyrotechnics. It’s a good solvent – that does not smell like it’s about to kill you and has a fast drying time. It’s hard to obtain in the UK (not to mention expensive), as pharmacies apparently cannot sell it (I heard that as it is drinkable – they will need to hold a alcoholic drink license for it… that’s just stupid – but I can think of a few people who will do just that). Also tax is levied because it is drinkable. For factories it’s less of a problem – large quantities can still be obtained for good prices.

Methylated is okay to use – but I find the vapours to give you one solid headache. They just hang around forever long after you finished your work. I can’t imagine allot of factories that can take the smell for long. Also, there are now three published works that connect between Methylated products and eye damage. The researches are done on people who work with those materials is regular bases – so probably will concern those here that are factory manufacturers, but it is something to bare in mind.

Isopropyl in my personal opinion is the best all around choice for the hobbyist. It’s widely available – light on smell, and has no risks associated with it. It is very similar in behaviour to ethanol – although drying times are longer.

Hope that helps.

Very helpful, My thanks to both BigG and TCblastmaster for thier detailed replies. I'll probably stick with isopropyl or ethyl if I can find it at a reasonable price. I think ethyl at 95% runs about 6-7 times the cost of isopropyl though. It tends to command a much higher price since it is a beverage.

[al.]

methylated spirits in the uk usually contains some water, making it activate any water-catalysed compounds. isopropyl is generally good as others have said, but can be quick to evaporate - in which case 2-butanone (methyl ethyl ketone) is useful. 2-butanone is also less poisonous than ethanol denatured with methanol (meth. spirits). methanol is a strong poison whereas 2-butanone is pretty harmless

[Arthur Brown]

Ethyl alcohol is drinking alcohol (please drink responsibly!) SO it is highly taxed. There are various denaturants used to suit various processes without incurring excise duty. Methanol, and pyridine can be used, as can light mineral oil.


Some mixes use alcohol to dissolve binders or to help the product to dry solidly.

[YT2095]

MEK and denatonium benzoate are also frequently used denaturing agents, what I would recommend is that if you have any doubts get a clean sheet of glass or petri dish and do a simple evaporation test, if it leaves no residue, Use it

[overflow]

As everyone said most of the time you can just use one of them, but be carefull when a certain project directly asks for a certain alcohol.

Ghost mines, for example, will only work well with methyl.

[Arthur Brown]

For every preparation you do, you should do an analysis of what could go wrong! And what you do to stop it going wrong.

Some processes need an (any) alcohol, some need pure ethanol, some pure Methanol. Part of being a competent worker is knowing (or finding) what the precise preparation conditions should be.

[al.]

blue pencil

Edited by al., 10 March 2008 - 11:34 AM.

[Zinginex]

Risk of sounding an idiot here but can you use white spirit as a binder alcohol? Or for granulating bp?