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Is Isopropanol suitable for cleaning aluminum ?

Posted: Fri Feb 08, 2013 6:43 pm
by noddybrian
I recently read with interest several warnings about cleaning aluminum with brake cleaner on another post - thanks for the heads up - I figured it just evaporated so there was no problem doing this ! I've welded most other processes for some time but am new to AC tig -my only aluminum welding previously was boken gearbox casings using a "spool on" MIG - the recognised prep being repeated wire brushing & heating with a propane torch till crud stopped appearing - my question is can I use Isopropanol as a safe effective cleaner as I have about 10 gallons of the stuff that was delivered by mistake so is free - whereas acetone is locally very hard to find & costs $15 for a quart can & I waste more than I use - the brake cleaner seemed to work well enough - was convenient in a spray can & came from £land ( like a Dollar store but $1,58 ! ) the next cheapest would be cellulose thinners ( about $15 per gallon )

Re: Is Isopropanol suitable for cleaning aluminum ?

Posted: Fri Feb 08, 2013 7:03 pm
by Otto Nobedder
Isopropanol is a good solvent for oils and organics, but not as strong as acetone.

But, hey, it's free! Just allow soak time. Some things can be soaked in a bath; others, just wrap with a rag and saturate and give it time to work. It shouldn't take more than a few minutes, but it isn't "spray and wipe" like brake cleaner.

BTW, the brake-cleaner warnings are mostly outdated. When chloroflourocarbons (CFCs) were used as propellent, you could easily make phosgene gas, a deadly nerve toxin. The end of CFCs was ALMOST the end of the problem. For a time, methylene chloride was a primary solvent, and may still be present in cheap-o products of Chinese/Asian/developing nation origin. MC doesn't make phosgene, but it does make some noxious stuff when burned, and is a potential carcinogen in it's natural state. If you look for a respected brand, and it says "non-chlorinated", it's fine. I use brake cleaner all the time.

Steve S

Re: Is Isopropanol suitable for cleaning aluminum ?

Posted: Sat Feb 09, 2013 5:22 pm
by TamJeff
I keep a spray bottle with a dilute solution of dawn dish detergent and water and a roll of cheap paper towels. Spray it on, wipe it off. By dilute, I mean, not much more soap added to the water than one might use for checking leaks in tires. I also use common bar (Lever works great) soap as a lubricant for my aluminum cutting tools as it seems to interfere less than stick wax does.

Re: Is Isopropanol suitable for cleaning aluminum ?

Posted: Sun Feb 10, 2013 2:28 pm
by noddybrian
Thanks for the advise guys - oddly went back & got a fairly decent weld on some of the same 3mm sheet I'd had problems with before but I did buy some acetone to clean it with just to rule out one variable - now I don't know if it's me / the retarded Chinese welder or the cleaning that's improved - I also found that I had a new left over 6" by 2" non woven ( Scotchbrite ) fine wheel from a stainless job I did that required surface blending of welded parts to match the suppplied brush finish box section & that worked really well cleaning the ally without making deep hard to remove scratches.