Denatured Alcohol

[cpubrp]

I've read in a couple a places where some claim you can use denatured alcohol to clean b/w negatives. Has anyone ever tried this or heard of this type of use?

 

[henpe]

Iso-propyl alcohol (IPA) will not swell the gelatin emulsion and can be used to clean a negative. (I have done this myself a few times...). I do not know about denaturated ethanol, if that is what you mean specifically?

Regards
Henrik

 

[halfaman]

The best seems to be isopropilic which is said to leave no marks at all, denatured alcohol is ethanol which is ok in pure form but I don't know if the additives to avoid oral consumption can have any negative impact.

 

[bripriuk]

'Denatured Alcohol' is 'Methylated Spirits' in the UK, and I have used it in the distant past for cleaning negatives. I found that lighter fuel (the Zippo type) is better.

Brian P

 

[AgX]

There are various forms of "denaturizing" ethanol, all based on adding a chemical that is repellant in some way or another. Here is is done by odour and taste.

 

[Donald Qualls]

Here in the US, I can buy denatured alcohol that's denatured with methanol, with gasoline, with an additive called "Bitrex" (the bitterest substance known), and possibly other stuff. Different additives have different potential side effects. Given what film cleaners specifically intended for film cost, I'm more prone to use those than trust to an unproven substance...

 

[Patrick Robert James]

I use 91% Isopropyl alcohol to clean negs. I only use it on the non emulsion side for cleaning, but I've dunked wet negs in it to speed up drying before. To clean the non emulsion side I put it on a microfiber then put the neg on a clean piece of paper on a had surface then wipe in one direction.

 

[dpurdy]

I have had pretty good luck on film and lenses using cheap Vodka. No residue. Rubbing alcohol leaves a residue in my personal experience.

 

[cmacd123]

some places allow that sale of "absolute alcohol" basically 200 proof Vodka. the price does include the tax on beverage booze. that is the purest ethanol that you can get. as others have said, the denaturing adds some sort of chemical to make the stuff undrinkable and some aditives may be worse than others.

this Kodak Licensee recommends 98% isopronal https://kodakdigitizing.com/blogs/news/how-do-you-clean-your-negatives
while entertainment imaging says don't use any alcohol https://www.kodak.com/en/motion/page/handling-of-processed-film#cleaning

the problem of course is that almost all or the traditional recommended cleaners have been banned because they are terrible for the Ozone layer.

3M does make a very expensive solvent which is blessed for film, but it is mostly in industrial quantities.

petroleum solvents like Lighter fluid are also used but have the flammability risk.

 

[Donald Qualls]

petroleum solvents like Lighter fluid are also used but have the flammability risk.

I doubt lighter fluid (naphtha, sometimes with a small admixture of heavier oils) is any more flammable than ethanol or isopropanol, though it does burn hotter when ignited. That said, I'd prefer to buy pure naphtha (used to be available as spot remover for garments) than use lighter fuel; if it's safe to take a tomato stain out of your heirloom wool skirt, it's as safe for gelatin as you're likely to get, and it'll evaporate cleanly.

Another nice option would be mounting fluid, as sold for getting the very best resolution and sharpness out of a top-end flatbed scanner. This stuff is meant for use on film, evaporates without residue, is (reasonably) safe to use -- and did I mention it's made for film? It's kind of spendy from the manufacturer of the fluid mount scanning accessory, but can be had at much more reasonable prices from bulk suppliers (or so I've read). I suspect it's just high purity naphtha (a nice combination of clean evaporating with limited fumes and flammability), but I'm not certain, having never handled or smelled the stuff.

 

[halfaman]

That said, I'd prefer to buy pure naphtha (used to be available as spot remover for garments) than use lighter fuel; if it's safe to take a tomato stain out of your heirloom wool skirt, it's as safe for gelatin as you're likely to get, and it'll evaporate cleanly.

Another nice option would be mounting fluid, as sold for getting the very best resolution and sharpness out of a top-end flatbed scanner.

I bought some mounting fluid years ago (KAMI SXL 2001) and, if my memory does not fail, it was basically naphtha.

 

[Wayne]

I often see lighter fluid recommended for cleaning because it has naptha, but I don't often see it pointed out that not all lighter fluid contains naptha and some contains none at all.

 

[AgX]

The american term Naphta means very different substances in Europe.


And I cannot get the US-substance here locally, but only at laboratory suppliers.

 

[Don_ih]

I once used a couple of drops of film cleaner in my basement darkroom, which is quite small. Within a few seconds, I had to leave the room. That is probably the nastiest stuff on earth.

If you're willing to let the negative dry, you could always put it in distilled water with some photoflo. Water is just about the only way you'll get dust off the emulsion, if it's dried onto it (even then, not likely to just come off).

I find denatured alcohol leaves a haze. And it stinks, too.

 

[john_s]

.......

I find denatured alcohol leaves a haze. And it stinks, too.

I wonder if the haze is an impurity that doesn't evaporate fully, or if the alcohol actually alters the emulsion, maybe slightly dissolving, which could look hazy when dry.

Here in Australia, the main brand of solvents available in the local hardware shops has a reputation among some fussy users that it leaves a residue after evaporating. So it's quite adequate for household and handyman use, but not if you're trying to use it for certain critical processes.

 

[Don_ih]

I wonder if the haze is an impurity that doesn't evaporate fully

I think there will be variation between brands of denatured alcohol. Truthfully, the stuff you buy to mix with shellac should not leave any residue - and that's what I have. I used it on a Kimwipe to clean my scanner glass - that's where I noticed the residue (it made the glass look hazy). Isopropyl alcohol doesn't leave any residue, though.

 

[AgX]

Here in Australia, the main brand of solvents available in the local hardware shops has a reputation among some fussy users that it leaves a residue after evaporating. So it's quite adequate for household and handyman use, but not if you're trying to use it for certain critical processes.

Easy to test wit a drop on a clean glass pane or clock-cover glass-dish.

 

[grain elevator]

Easy to test wit a drop on a clean glass pane or clock-cover glass-dish.

But do make sure it's glass, not acrylic; that can fog or worse from alcohol!

For isopropanol, it's worth shopping around. My local pharmacy of all places gave me an excellent price. That was before Covid though. I had read somewhere in the internet, maybe here, that pharmacists (at least in Germany) think of the watered down stuff when you say "Isopropanol", so you need to ask for "2-Propanol".

 

[runswithsizzers]

What is it on the film that you are trying to remove?

 

[AgX]

Does one typically know this? If knowing so, one can start with apt solvent or means, of not it is a matter of try and error.

 

[runswithsizzers]

If the problem is fingerprints (oil), then solvents like naptha or alcohol are likely to be effective. But for dust, would solvents offer any advantage over an antistatic brush and blower? Some of my old slides have patches of fungus that seems to be etched into the emulsion, and the solvents that I have tried so far have not been effective on fungus.

 

[cpubrp]

What is it on the film that you are trying to remove?

Fingerprints

 

[Wayne]

Fingerprints

Sulfuric acid gets rid of those...wait, I'm thinking of something else.

 

[cramej]

Here in the US, I can buy denatured alcohol that's denatured with methanol, with gasoline, with an additive called "Bitrex" (the bitterest substance known), and possibly other stuff. Different additives have different potential side effects. Given what film cleaners specifically intended for film cost, I'm more prone to use those than trust to an unproven substance...

Off-topic - thanks for mentioning Bitrex! I did some research on it and found it is used in many substances to deter consumption, including in pet deterrent sprays. I ordered some (the generic version, anyway...denatonium benzoate) and made my own to spray on landscape rock to keep my dogs from playing with and/or eating them. Time will tell how well it works but it was really f'in bitter mixed at ~100ppm!


On-topic, why not use Carbon Tetrachloride.........





Just kidding, please don't!

 

[Donald Qualls]

Yeah, that stuff is "liver transplant in a bottle."