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Alcohol as coolant on aluminum

garyhlucas

Stainless
Joined
Oct 17, 2013
Location
New Jersey
I saw a research paper recently that said alcohols reduce cutting forces on aluminum by as much as 50%. I just cut hundred of counterbores on 8020 extrusions and also some 6063 box tubing using alcohol in a fog buster style mister. My machine is a light duty home built CNC mill with a router for a spindle when cutting aluminum. I was pleasantly surprised at how well the alcohol worked. No problem with chip packing or BUE even on the 6063 that has given me fits in the past. I used 90% drug store Isopropyl. Easy chip cleanup as it evaporated so quickly the chips were dry.

Anyone doing this with real machine tools?
 
Interesting experience with the 6063! I have machined enough to know what a PITA it can be. What was the base reference for the 50% reduction in cutting forces? Was it dry or with a coolant?
 
Yeah, lots of high precision type machines use isopropyl. Datron for example in the US. The oils can get annoying for high tolerance/small tooling type work. For light duty work like your though I would recommend WD-40. I use it a lot on smaller jobs where flood coolant isnt available. It also helps to have lubricity if your tools are worn as it helps a lot with chip evacuation.
 
I have used kerosene for aluminum many times. Currently, I use a spray bottle of WD-40 when cutting aluminum on the manual lathe.

Kerosene (or other light oil) is an ancient recommendation for aluminum. This is the first I have heard about alcohol. I will have to give that a try, as the cooling effect will be huge compared to oil, and I happen to have 98% isopropanol in a spray bottle already.
 
Curious about how to use it as well. A spray mister maybe? What about breathing in the fumes, or flammability as mentioned above?
 
Used alcohol in a spray bottle all the time for 6000 series extrusions and also 5000 series marine plate.... in a large shipyard. It did limit tooth pickup but not as well as saw wax. The problem with saw waxes is that they can contaminate weld joints.
It was the most practical for using with large hand held routers with carbide cutters, half inch shank. One person running the router and the other pump spraying.
 
I knew someone would ask where I saw it! I'll have to check. Note that I use a fog buster style mister that doesn't really put out mist but larger drops. I can run the machine all day and you never see any mist in the enclosure. I have used a Spraymist unit in the past and that would fill the whole shop with mist in no time. Very bad for your health I think.
 
Post a link. Really doubtful unless against pure dry which would be stupid and brainless.
Coatings, speeds, rakes, force measured how? Show me this data.
Bob

I can't give you data, just direct experience from cutting Al spacecraft parts ~22+ years ago using an alky mist to cool/lube the endmills. I can't remember if I came up with the idea on my own or read about it somewhere, but after some simple tests found that it worked well with bare carbide cutters.

I did some purposeful tests to see if I could ignite the mist with a welding sparker, and never got it to "poof" even with prominent sparks. Didn't try a direct flame, though.

One nice aspect of working at a university at the time - I had access to reagent grade ethyl alcohol, so if there was a buildup of vapor at worst I'd get drunk rather than poisoned. I guess they trusted me as my supervisors knew I didn't drink. :D In truth, never noticed any ill effects, but I had a welding hood not too far away that I kept on to help with ventilation.
 
Holy cow! That study implies that just writing on piece of Al with a Sharpie is an effective stress raiser. That has implications for a lot more than just reducing cutting forces.

Also worth noting is that isopropanol has zero effect on Cu or Fe, despite the large effect on Al. On the other hand, various glues and inks (!) were effective on all three metals to some extent.

Tests were done on material in the annealed condition (soft, gummy). Might not apply to material in a higher temper condition.
 
Holy cow! That study implies that just writing on piece of Al with a Sharpie is an effective stress raiser. That has implications for a lot more than just reducing cutting forces.

Also worth noting is that isopropanol has zero effect on Cu or Fe, despite the large effect on Al. On the other hand, various glues and inks (!) were effective on all three metals to some extent.

Tests were done on material in the annealed condition (soft, gummy). Might not apply to material in a higher temper condition.

I seem to remember a thread on this, or a discussion in another thread, not long ago. The sharpie sticks in my mind.
 
I seem to remember a thread on this, or a discussion in another thread, not long ago. The sharpie sticks in my mind.

I also recall that thread, to the point that I scrolled up to check the post date on the OP, to make sure I wasn't reading an old thread again.
 
Kerosene (or other light oil) is an ancient recommendation for aluminum. This is the first I have heard about alcohol. I will have to give that a try, as the cooling effect will be huge compared to oil, and I happen to have 98% isopropanol in a spray bottle already.

Alcohol (with or without added soap) is ages old cutting fluid for aluminium at least around here. Milk for copper goes to same category.

I bet not many use whole milk for copper machining on CNC's either :D
 
I jokingly mentioned using whole milk for machining copper at work once and was told in no uncertain terms if I filled the sump with rotten milk the whole shop would kick my ass.
 
As a student I discovered that methanol and acetone worked well for tapping aluminum. One benefit it the rapid evaporation rate that helped the chips fall right off of small taps. It makes sense that these solvents should help cutting forces for milling and turning.
And also that plain water worked great for Plexiglas.
 
I use Alcohol a lot for sawing 6061 and have found spray-n-wash works great for tapping on the Bridgeport ,,, I was using A-9 for tapping but it left spots on my shirts as did WD-40 … I get gallons of Spray-n-wash at Costco and use it on all my manual machines for alum ..
 








 
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