Ethanol mist for cutting aluminium

[matt-b2]

Hi,

Has anyone here got any experience using ethanol delivered via a mister system when high-speed cutting aluminium? I understand that's what Datron use in their machines. At the moment I'm using WD40 which works but makes a horrible sticky mess when mixed with aluminium chips/dust and tends to stink the workshop out. I also have issues with the WD40 separating in the mister reservoir (the bottom of the tank ends up with white fluffy looking stuff floating around in it).

Are ethanol fumes an issue? Where can I economically source ethanol, in appropriate form, a few litres at a time? So far I've only been able to find bioethanol (the purity of which I'm unsure about) and methylated spirits (which probably smells worse than WD40) in bulk.

Cheers,
Matt.

[phill05]

Hazard Communication Sheet ETHANOL C2H5OH Ethyl Alcohol DESCRIPTION Clear, colourless, mobile liquid with characteristic odour; m.p. -130o C; b.p. 79o C. Miscible with water. CAS: 64-17-5. UN number: 1170. HEALTH HAZARDS IRRITANT: Irritating to the eyes Eye contact with liquid causes pain and severe irritation. May cause chemical conjunctivitis and corneal damage. Exposure to high vapour concentrations causes irritation of the eyes and respiratory tract, headache, giddiness and nausea. Swallowing causes narcotic effects (headache, giddiness, nausea, vomiting with coma and death in severe cases).Repeated excessive intake causes liver damage. Liquid degreases the skin and repeated contact may cause cracking. FIRST-AID Inhalation: Remove from source of exposure. If breathing stops or shows signs of failing apply artificial respiration. Use oxygen if breathing is laboured. Obtain medical help. Skin Contact: Remove contaminated clothing and flush affected area with water for at least 15 minutes. Treat patient as for inhalation. Obtain medical help. Eyes: Flood with eyewash or water for at least 15 minutes. Obtain medical help. Ingestion: Wash out mouth with water. Treat as for inhalation. Obtain medical help. SAFETY HAZARDS INCOMPATIBLE with strong oxidising agents, acids, alkali metals, ammonia, hydrazine, peroxides, sodium, acid anhydrides, calcium hypochlorite, chromyl chloride, bromine pentafluoride, silver nitrate, mercuric nitrate, potassium tertbutoxide, acid chlorides, platinum, uranium hexafluoride, silver oxide, iodine heptafluoride, acetyl bromide, disulphuryl difluoride, tetrachlorosilane + water, acetyl chloride, permanganic acid, ruthenium (VIII) oxide, potassium dioxide. EXPLOSION HAZARD. Forms flammable/explosive vapour/air mixtures. Take precautions against static discharges. Ground and bond containers when transferring bulk material. Use spark-proof tools and explosion proof equipment. FIRE HIGHLY FLAMMABLE. Flash point 12o C. Explosive limits 3.3-19%. For small fires, use dry chemical, carbon dioxide, water spray or alcohol-resistant foam. For large fires, use water spray, fog, or alcohol-resistant foam. Use water spray to cool fire-exposed containers. Do not use straight streams of water. Use self-contained breathing apparatus if fire is large or in a confined space.

[Christian Knuell]

Hi,

Ethanol burns and if you're unlucky you can create an explosive aerosol - but small quantities with good ventilation in a big room are usually no issue.

The trouble starts if the quantity is too large to evaporate rapidly so you end up with a pool of highly flammable liquid or if the machine is in an enclosure or small room with bad ventilation where explosive concentrations are easy to create.

The cost for pure ethanol is mainly a question of taxation - there are no cheap sources for alcohol in food-safe quality. But purity is not an issue for machining.
From a health point of view it is always good to minimize exposure to any vapor - but if you only have the choice between alcohol and other coolants alcohol will usually be the lesser of two evils.

So... be aware of the fire and explosion hazard, keep a suitable fire extinguisher around and never let the machine run without supervision.

Christian

[komatias]

As the guys said, it is flammable. The vapours can make you drunk and prolonged exposure will blind you. Now in order to get it in any quantity in the UK you need a special license. This is to control the alcohol production for public safety.

There are better ways to apply coolant. WD40 is expensive so i always use a water soluble oil coolant. Have a look at misting systems that have air assistance. They are cheap and work well clearing chips.

[magicniner]

Straight Paraffin works nicely for soft aluminium.
90/10 to 70/30 Paraffin to 20 weight oil gives good results with a wide range of materials.
You will still need extraction for any mist system which creates any airborne contamination in your workshop,

- Nick

[Tenson]

I think it's methanol that makes you blind rather than ethanol. Please let me know if you find a source for ethanol I might like to try it for the occasional ali cutting (seems like you can get bio-ethanol for fireplaces). The mess of oil or water is an issue for me too.

Both methanol and also isopropyl alcohol are easy to get hold of but both are very bad for your health so make damn sure you don't breath too much. As little as 250ml consumed can kill.

As for WD40 seperating from the water you need to get a water soluble oil. People call it 'cutting oil' and mixed with water 'white water'. http://www.ebay.co.uk/itm/G-P-Solubl...3D111574149025

[magicniner]

As little as 250ml consumed of either can kill.

Evaporated into air you could make a huge explosion before you got anywhere near exposing yourself to 250ml ;-)

[cropwell]

Just a further cautionary note - Ethanol burns with a near invisible flame.

[komatias]

is this the article the OP is refereing to?

http://www.mmsonline.com/articles/al...ndly-machining

Still not a particularly safe way of going about it. I wonder if Krytox would be good for the application though. Low viscosity, low evaporation and water based too.

[magicniner]

is this the article the OP is refereing to?

http://www.mmsonline.com/articles/al...ndly-machining

I doubt it as extraction, containment and fire suppression equipment are stated to be implemented for alcohol use, you wouldn't need to worry about the smell in the workshop if that was or was intended to be the case,

- Nick