View Full Version : Wet Plate Collodion - Alcohol

27-Sep-2016, 08:31
Hi everyone!

New to this forum and wet plate collodion. I actually had a question regarding the alcohol that many aspects of collodion chemistry call for. I understand I'm meant to be using denatured alcohol but this is where I get confused. As far as I can tell, denatured alcohol is an American term, I'm in Australia and can't find what the equivalent would be. According to Google, it's 'Methylated Spirits' but I have been turned away from that due to too many unknown additives. Just wondering if anyone has a preference of alcohol? Thanks, Elliot

Monty McCutchen
27-Sep-2016, 09:13
I use Everclear or its equivalent.


Eric Woodbury
27-Sep-2016, 09:33
Ethanol is what you want. Denatured means it's been poisoned with a splash of methanol (wood alcohol), so you shouldn't drink it.

27-Sep-2016, 10:18
People have used this as an alternative. I don't have experience with it as I've only used Everclear but I don't see any reason why it wouldn't work.

Moda Flame 1 Quart Bio-Ethanol Fireplace Fuel 12 Bottles https://www.amazon.com/dp/B00FHLGU3S/ref=cm_sw_r_cp_api_YCQ6xbV1S6N2W

27-Sep-2016, 15:39
Thanks for the help everyone. I'll definitely check out that bio ethanol

Fr. Mark
28-Sep-2016, 07:09
In the US drinkable alcohol (ethanol or C2H6O) has a lot of taxes on it. If you want it for paint thinner or fuel they mix it with various poisons (toluene and or methanol C1H4O being typical) and can sell it w/o taxes and liquor licenses in hardware DIY stores. Ever clear or grain alcohol is around 190 proof or 85-95% ethanol, the rest being water. It is very difficult to remove the last few percent of water from ethanol made from biological sources---it co-distills as a tightly bound complex (azeotrope) so distillation won't do it. In the lab if we needed scrupulously water free ethanol we would boil it in a flask with a reflux condenser with magnesium chips in the flask. Then the flask would be allowed to cool using something to exclude regular moisture from the air (variety of techniques). I imagine there has be some kind of ultra high percentage ethanol for sale in Oz. If not read labels carefully. Methanol would be less trouble for wet plate, I think, than toluene. Toluene absorbs UV very well, it is also oily and has a relatively high boiling point so is hard to get rid of. Methanol does not.

28-Sep-2016, 09:37
In some US states it seems difficult or impossible to get Everclear. Even when other (ahem) previously banned substances are legal. A bit ironic. The bioethanol seems like an intriguing work-around.

28-Sep-2016, 22:42
Fr. Mark is right about the ethanol/water azeotrope, but industrially anhydrous ethanol is (or used to be) made by co-distillation with benzene. The details of physical chemistry are not important, but the fact that benzene was left in the product was a very good reason not to use the laboratory alcohol for the Christmas party punch. Over the years, many different denaturants have been used; my favorite was aviation gasoline... The law here requires that the denaturant make the alcohol "unfit" for human consumption, and not practially removable, the logic being that any particular denaturant might not be compatible with some legitimate technical use.

If in Australia as in the U.S.A, beverage (i.e., safely drinkable) alcohol is regulated federally, it is likely to be quite expensive regardless of what it is sold for. If bioethanol sold for fuel is significantly cheaper than Everclear (sold in liquor stores, at least in Texas) then it is almost certainly denatured---and the nature of the denaturant may or may not affect the collodion process.

Methanol may or may not be a suitable substitute; nitrocellulose is soluble in a mixture of (ethyl) ether and ethanol, but insoluble in either one alone. Not only is methanol more toxic than ethanol, but it may not work!

Fr. Mark
29-Sep-2016, 18:56
If you want to drink lab ethanol get the USP stuff. Agreed.
Don't forget that Methanol (MeOH) is motor fuel as is ethanol (EtOH) and that Ether is very flammable and explosive in a lot of air/fuel ratios. And nitrocellulose is a quite energetic material too.
There are major solubility differences for different materials in EtOH v MeOH. Not sure how much MeOH is used as denaturant. It wouldn't take much to make the EtOH poisonous and that amount might not mess with photo chemistry. Or it might. Please let us know if you do the experiment.

Fr. Mark
29-Sep-2016, 18:58
Industrial EtOH is also made by adding 1 water molecule to one ethylene molecule. If you get it exactly right, and I presume the Chem Engineers can, you get completely anhydrous EtOH which would be useful in making a lot of other chemicals.

3-Oct-2016, 22:22
For anyone in Australia who is interested, i got in touch with Ellie from Gold Street Studios who put me onto this stuff that she's been using for years: https://www.chemsupply.com.au/al048-2-5l-p

15-Sep-2018, 01:12
I'm in Australia and was following this thread to find Denatured Alcohol here.
I think the link above is broken, but searched their site and found this, which I believe is what was linked to: https://www.chemsupply.com.au/absolute-alcohol-100-denatured-lr-packed-in-uhdpe-bottle

@guywithacamera - any other tips on where to source chemicals, aluminium plates or other wetplate related bits in Melbourne/Australia?

15-Sep-2018, 03:39
FYI, I (and many others) have found that the choice of alcohol is much less critical than what some want to make us believe. I successfully use generic bio-ethanol (around €2 per liter) which is something like 96%. Anything above 96% purity is problematic due to two reasons: fractional distillation is theoretically and practically limited to a purity of 96% because alcohol and water form an azeotrope, meaning that the remaining 4% water cannot be removed by distillation and additional 'drying' must take place, making the product much more expensive. The second problem is that 100% alcohol will not remain 100% due to the hygroscopic nature of ethanol. Simply put: the alcohol will absorb moisture from the air and over time, an opened bottle of 100% ethanol will automatically transform itself to an azeotropic 96/4 ethanol/water mixture. But most importantly, I personally found (and like I said, so did many others) that the small fraction of water isn't a problem for wet plate applications. Any generic 96% denatured alcohol will do just fine, as long as no colorants etc. have been added.

Fr. Mark
15-Sep-2018, 22:55
I thought the azeotrope was more like 85/15 alcohol/water, but it’s been a very long time since I had to know. I was going to say some dentaurants could be an issue, but the more I think about the less sure I am. I guess I will point out that there are several such mixtures involving toluene, Methanol, etc., and for consistency you might want to get the same kind each time.