I have a bottle of Isopropyl Alcohol USP 70% in my house. I did use it to clean some battery terminals the other day and the IR readings when in my charger went back to normal which is good, but, does it melt the wrappers or any other cautions using this type of alcohol?
I have been using 90% for a long time cleaning cell ends and different parts of flashlights with no negative effects that I have noted.
I wouldnāt think the 70% would cause any negative effects either , unless it might cause some surface rust possibly on untreated or bare metal since the 70% does contain more water than the 90% does. (30% for the 70 vs 10% for the 90)
I do it all the time. I even use it on the threadsā¦
Well, that does it then, I will keep using it and next time get 90% for less water content!
The 90% also has worked well for rinsing my chemically dedomed emitters over time as well as a quick rinse for the hot dedomed and sliced ones. I use it for cleaning reflectors and lenses a lot and it works well for that , where the 70% many times would leave tiny spots , much like using distilled water. Also cleans most surfaces well for soldering.
EDIT: when using to rinse reflectors or lenses , I use a light spray of air to blow away the droplets. Even then the 70% many times would still leave tiny spots where the 90% usually does not.
Going to look for that 90% tomorrow and keep it in my flashlight cabinet. Never thought of trying alcohol for cleaning the lenses and reflectors. Might give that a try soon too. I still have a fair size bottle of Monster Screen Clean that I use for my monitors and that is what I have been using so far to clean all my flashlight lenses since that bottle never seems to run out. Had it for several years now.
BTW 99.9% is also very easy to get. (at least in germany)
Car detailing companies also often have these in 1l bottles for degreasing.
I only use 99.99999% or better.
Where do you find that stuff in BC 
Is this attempted mockery? 
I think thereās no 100% rating, itās always 99.9% minimum rated.
99% isopropyl alcohol is about the best cleaner/degreaser you can find - and if you have soap scum in your sink or on faucets, it wipes that stuff away like magic. Any residue evaporates in seconds.
I use 70% for after shave as my wife doesnāt like strong fragrances (and many health care services here ban fragrances in hospitals and clinics). Most after shave lotions are just 70% isopropyl to begin with, with a shot of āstinkumā added.
Shoppers Drug Mart.
Look for Isopropanol.
I was just responding to Enderman kidding about the 99.99999% purity!
Ummm, IPA is an azeotrope at something like 87ā88 or so, so anything āpurerā will just absorb water from the air as soon as the bottleās opened.
90% is about as good as youāll getā¦ and be able to keep.
Just picked up 99% at walmart this morning or as you say, "87%-88%" once I open the cap 
Itās extremely difficult to get CP isopropanol, because unless itās kept pretty much in a vacuum and sealed, any water vapor will be sucked right up. Not immediately, of course, but over time.
Same reason you should pretty much never get brake fluid and/ot steering fluid in more than you immediately require, because theyāre hygroscopic and will suck water right out of the air when exposed, and that little bit can rust the lines from the inside.
So whenever I need IPA, Iāll spring for the 90%, but rarely (read, never) anything āpurerā. Certainly not in an unlined plastic bottle.
Good info there thanks Lightbringer 
Bottomless pit of knowledge. :+1: