Picture of How to
Salting out is a process that can be used to dehydrate Isopropyl alcohol, i.e., separate it from water in an azeotropic solution. Dehydrated Isopropyl is useful as a fuel by itself and in helping to determine the right amount of catalyst to add when making bio-diesel fuel.

Removing water also increases the Isopropyl alcohol's ability to:

> melt ice off your frozen windshield
> dissolve water in gasoline
> burn cleaner when used as a standalone fuel
> provide your pet with an invigorating rub after his next bath, which is curiously strong enough (dry enough) to dislodge stubborn ticks and fleas
> serve as a powerful pet or human wound antiseptic
> wash out those wax filled ears
> save you big $$$ (dough, ka-ching, moola, etc.) think money*

(*99.9% Isopropyl Iso-Heet at auto stores runs around 18.25 cents per ounce. 99.9% Isopropyl made from salting out 50%-91% generic retail brand Isopropyl runs around 6.73 cents per ounce. That is a savings of over 63%. If you use it to dry your gasoline then be sure to remove the residual salt using the addendum method.)

What you need:

- bottle of 50% to 70% Isopropyl alcohol
- a wide mouth glass jar and lid, or other leak and Isopropyl proof container
- a pound of non-iodized table salt
- a turkey baster with a reduced size nozzle
- an empty bottle equal in size to the bottle of Isopropyl alcohol.

Step 1: Start by adding the table salt

Picture of Start by adding the table salt
Fill the empty jar about 1/4 full with table salt
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ricor4311 months ago

Is there anything that can be used in place of salt? If not, how can I get the salt out of the alcohol?

cmadsen5 ricor433 months ago
At the end of thinkahead's instructable (he/she) suggests that if you don't want salt in your isopropyl alcohol, that you should distill it.

Try some cheesecloth.

QiangX4 months ago

Thanks. Can this method be used to salt out 70% ethyl rubbing alcohol?

dillonxti4 months ago
thanks worked for me
botronics2 years ago
Can this work with Vodka? I need pure ethanol for making a Fitzroy Storm Glass. Which is a mixture of camphor, ammonium chloride, potassium nitrate, water and ethanol.

sounds like a illegal substance lol starts with a m

Che_Surfer6 months ago

All I can get is the 99% where I live and really want 99.9 to 100. Is it worth it to salt out? I can't stand 99% wish I could just find barrels of the 99.9 reagent here :(

DanC48 months ago

Chemist chiming in. I don't know if anyone else has stated this because there are too many comments for me to look through all of them, so apologies if this statement is redundant.

99.999% IPA is a WORSE disinfectant then 70% IPA. There is a reason why the IPA in the pharmacy is 70% IPA and 30% water and that is because the water actually improves the efficacy of the product as a disinfectant. Alcohols as disinfectants are most effective in the 60-90% range, above or below that and they become less efficient at denaturing the microbe's proteins.

Also, please note that while alcohols are broad disinfectants and can kill a lot of different bacteria and fungi as well as deactivating viruses, they aren't as effective as say bleach or peroxides for killing dormant cells or spores that are designed to weather harsh conditions. So if something needs to be 100% for sure clean (for example, surgical equipment or for people with compromised immune systems), it's best to use a harsher product.

That being said, IPA is an excellent, topically safe (i.e. it's safe to touch, not to drink) product that does a really good job at making surfaces microbe free for most conventional purposes. Also it evaporates away after using it, is less damaging to surfaces and doesn't leave behind a bleach smell. Score!

Pbyrd1 year ago
This is probably a rather ignorant question, but I'm assuming any sort of non-iodized salt would suffice? I have non-iodized sea salt, so I'm assuming this would work fine, but I wanted to make absolutely sure.
J@50n5 years ago
just wondering, is this the same as denatured alcohol?
alhewy J@50n1 year ago

No, "Isopropyl Alcohol" is the working name for the chemical compound 2-propanol (C3H7OH) usually mixed with water to about a 70% purity. "Denatured alcohol" is the working name for ethanol (C2H5OH) that's got nasty additives in it. They add impurities to deter people from drinking it... but I guess some hobos will always go for the cut-price booze, even to their own poor health :)

Qcks5 years ago
Just gonna add...
If you're having issues with salt residue in your isopropyl, you can limit the solubility of the Sodium Chloride by doping the isopropyl with sodium hydroxide prior to salting it.

This has the advantage of having a solvation effect with the salt and the base (Sodium Hydroxide competes with Sodium Chloride for solvation with the water because both have a sodium cation). Any residual hydroxide compound should burn clean.

The biggest downside is that you might begin to push your isopropyl to undergo a synthesis reaction, but due to it's shape that's not very likely (that is to say, it's stearically hindered, and thus, unlikely to undergo any synthesis reactions).
lpkid1057 Qcks5 years ago
Love the pedantic organic chemistry guy here.

Why you insulting him? He is answering someone's question and giving a good practical answer.

dmars1 year ago

Does anyone know a good way (cheap, not too involved manual labor) to get the salt out of the alcohol? I'm using it in an antique alcohol lamp, one that has a longish chimney, and the salt comes up the wick in rather huge quantities. It's a pretty orange while it's burning, but after it completely burns there's a solid crust on the end of my wick and the flame goes out. I have to trim the wick and relight it about every 15 minutes. Salted out IPA (isopropyl alcohol) with the salt somehow gone would be perfect!

DrSimons1 year ago
Nice instructions, I'll try adding more salt (had tried this previously with mixed results, but I didn't use nearly as much salt). One thing: BE CAREFUL if you decide to distill anhydrous IPA, let alone fuel, as hinted in the intro. If you are gonna do that, make sure you use a hot plate or other electric heat source, i.e no open flame. Probably don't even try it with gasoline, unless you want to read about yourself on the local news (as a ghost).
Just tried this, stove works much better thanks! I put the Isopropyl in the same container. Crossed out the fifty percent and wrote 'much higher'.
ironLes43 years ago
can you use a salt subtitute
hahahaha, funny
You could put the salt on your margarita for a scientific buz...or was the alcohol in the water?
Isopropyl alcohol is definitely not something you want to drink. Not all alcohols get you drunk, as far as I know ethanol is the only one that does it without some pretty nasty side effects (although hangovers aren't too fun ;))
I have read that if you drink isopropyl alcohol it can cause blindness or even death.
most alcohols actually cause blindness, and ethanol is really the only alcohol thats safe to drink (not that its that safe eh ;D ) most other alcohols cause blindness in really small quantities, and theyr all very lethal poisons.
junits156 years ago
what happens if I use iodized salt?
Most likely reason why people say to not use iodized salt is because it has iodine which can either A) make I2 which is non polar and may mix with alcohol as apposed to the water or B) could make a iodo-*suffix* compound.
Only speculation from a hobby chemist though.
dammat6 years ago
Wouldnt silica gel work to remove the water? I found an experiment online that somehow used silica in a distillation column to remove the water. The water vapor is easil absorbed by the silica gel. Silica will retain up to 40% of its weight in water. Seems like a good idea to me. Otherwise I would research how its manufactured on a larger scale.
Broom dammat6 years ago
Seems to me the problems are: 1. You'd need 2.5x the weight of water in silica gel - that's a fair amount, and salt is easier to come by. 2. Is silica gel soluble in isopropyl alcohol? If so, it wouldn't work at all. 3. Does silica gel absorb isopropyl alcohol? If so, it wouldn't work at all. Seems to me table salt is the better solution (no pun intended).
You could use lime to do the same thing. When I was growing up, my dad taught me this trick.
Take some ordinary dry wall and bake it in a toaster oven OUTSIDE. The paper on the outside may burn off. The lime left behind will be completely dried out. Take the lime and crush it into as fine of a powder as you can. Add it to your alcohol and mix thoroughly. Let it set over night and either re distill or  use a sepratory funnel to get the end product.
 We had a farm that had a large above ground gas tank for refilling our tractor. It would accumulate water and had to be dried out. 
patmccock5 years ago
i used 91% isoproply alcohol and it wont work why is that?
Thats what the product is suppose to be. If you use more dilute alcohol this will work. Just add some water to this and see :P
Methyl and isopropal can be absorbed through the skin, if you use it a lot it can have bad effects on you, rub downs with alks should only be with ethyl. They tell you now never rub your kid down with it . When I was a kid everyone knew to use rubbing alks for fevers. No Mas muchacha
isopropal is lousey for alcohol stoves, methyl is great , but ethyl is best (more btu's. Since we can drink it it is heavily taxed. Denatured alks are mixtures and can have ethyle and methyl and other crap. The other crap will soot pans and in some cases stinks like heck. Go to the site for S-L-X denatured alcohol, the stuff varies. GO to Minibull Designs.com and look for Tinny's fuel comparasons, it explains much. This is a great article/instructable. You could if you had equipment, or really cold cold streak, do cryogenic distillation. Put a few gallons in a drum freeze it to -20 for say a few days then let it 'warm to -10 few hours, then refreeze to -20, do this a few cycles and ice crytals will form on out sideof alcohol column. Well it does with hard apple cider. But you need those frigid upstate NY death by cold winters. Farmers could leave casks of hard cider freeze then pop a hole in the center and drain off the liquer. Not worth the effort though. Buy heet or Air Brake Antifreeze, pure methyl spirits, 98%. If you are lucky enough you may find a speed shop that sells it by the gallon out of a drum, (bring clean jug/can) 4-8 bucks a gallon. Sadly I can't find one by me. I enjoyed this piece I will re read later on in the week.
slurp slurp bubble bubble gurgle gurgle haha very nice.
Berkin6 years ago
What happens if you use iodized salt?
I doubt that.
chuckr447 years ago
I'd be interested if you used a beer-making specific gravity meter for alcohol, to measure the SG of the alcohol your produced. Is it closer to 90%? Is this method efficient? Thanks for a great instructable.
thinkahead (author)  chuckr447 years ago
You are welcome and thanks for the compliment. Just as I was getting ready to build a hydrometer it dawned on me that all I really need to do is to measure volume and weight. I have a good postal scale and volume is also pretty easy to measure with just kitchen wear. All measurements so far confirm 99-100% Isopropyl.
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