Question How to safely remove thermal paste from CPU pins?

Normally like dissolves like, so highly polar solvents such as water or alcohols like methanol or ethanol should have no effect on silicone grease. The more nonpolar structures there are on the alcohol the better it will work on light oils, so isopropyl is slightly better than those but worse than say, isobutyl. Isopropyl is normally used to clean rosin flux (which is pine pitch) after soldering, but silicone grease is just too thick for it.

However you don't actually have to use silicone oil as any hydrocarbon solvent is also nonpolar so will dissolve silicone greases. Such solvents can often leave behind a light oily residue which can be flushed off with plenty of alcohol or even soap and water. The trick is of course many hydrocarbon solvents such as acetone will aggressively attack plastics and PCBs, so it's best to choose a spray electronics cleaner or MAF cleaner and stay far away from anything not intended to clean plastics such as brake cleaner.

Soap cleans both water and oil soluble stains... because one end is polar and the other is not. In water the nonpolar parts all come together to form a micelle around the oil particle. Just be aware things like dish soap contain a whole lot of electrically conductive salt so be sure to rinse well.
 

punkncat

Polypheme
Ambassador
Arctic's cleaning solution is actually an 'orange cleaner' much like goof off. Something along those lines with a very soft bristle brush will clean that. The second part of their solution is alcohol. I will mention that if you use something like the "pro strength" Goof Off, it dries your hands out severely. It also eats through rubber gloves.

I would also bet, as mentioned above, that some soap and water alongside physical manipulation (like a toothbrush) will likely do just fine.
 
Goof-Off Pro is by far the most effective and fast-acting of the commercial sticky residue removers, which can kind of be expected as it only comes in a metal can. Unfortunately its SDS lists a whopping 60% acetone in it with some xylene for good measure, so it will immediately remove varnishes and damage plastics and paints.

Oops! only contains a small amount of acetone and oil, but is mostly lighter fluid or gasoline/Coleman Fuel. Librarians use pure lighter fluid to disassemble and restore books as any oil would stain paper, so if you were wondering why your library has an OSHA-approved flammables storage cabinet, it's not for book burning supplies.

Goo-Gone is the mildest, being kerosene and citrus oil based. Think of it like Pine-Sol (which is pine oil based soap solution) or citrus cleaner (citrus oil in soap) only with a lot more oil and less water, as the instructions call for washing it off afterwards. This one requires the most scrubbing to work.
 

wyliec2

Splendid
Apr 4, 2014
214
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21,890
I have 97% or 99% isopropyl along with the Arctic Silver thermal compound cleaner - both work effectively but what I use the most are lens cleaning wipes in foil packages moistened with alcohol.

Only takes a couple of wipes and then finish with q-tips in nooks and crannies and a paper towel to wick off the last remnants of compound and leave the CPU dry.

Since they're designed for camera lenses and eyeglasses, they dry perfectly clean with no residue.
 
You know it's kind of weird that no store chain besides Kroger and its subsidiaries carries 99% isopropyl alcohol in-store--but 91% is everywhere. Well unless you wanted to buy a huge gallon jug at Ace Hardware. Both carry Swan brand of 99%.

What may partially explain it is 99% is too strong to kill germs as well as 70% does, something to do with drying them out to a dormant state instead of killing them. However 91% is also much less germicidal than 70%. In any case we are not using it for that here anyway.

Well, isopropyl is cheap, so even if it's not all that effective at cleaning grease you can just use a whole lot of it. Just poke a tiny hole in the seal instead of removing it and you'll have a squirt gun you can use to kind of pressure wash the paste off.