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Pro Tip: Drilling Aluminum Enclosures

Started by rullywowr, July 27, 2016, 05:56:28 PM

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I have been doing a LOT of enclosure drilling lately with my trusty drill press, center punch, 1/8" drill bit, and step bits.  After galling a few older bits beyond repair (and buying a new $20 one at my home improvement store) - I found a tip on the home machining forum regarding drilling holes in aluminum.

Use a small squirt of isopropyl alcohol as a lubricant when drilling.  Any concentration (70% - 91%) should work fine.  This cools the bit and makes drilling go a lot better - especially when drilling lots of holes.  It will make your bits last a lot longer too.

I wanted to drill before I powdercoat and screen print, but I didn't want to use any oil which would screw up the coating process if not removed.  The alcohol is wonderful as it works well and evaporates fairly quickly.  The only downside I can think of is that the small water content in the alcohol may rust your drill press if left in contact with it.

I'm sold on this completely.  I keep a small Harbor Freight plastic wash/squirt bottle near the press now just for this use.  Hope someone out there finds this useful.

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Great tip Rully!

Isopropyl alcool is also what we use to clean the surface of aluminium before TIG welding it as it removes most of the grease deposit on the surface to be worked.

The cast aluminium that is used for enclosures is very porous (is that a word? porosity??? lool) Could also be usefull for cleaning for those who etch, i think.

On another note, it's highly recommended when drilling or machining aluminium that the blades, drill bits have a TiNi coating (the goldie stuff, Titanium Nitride), it helps a lot for the aluminium to not stick on the tools and heat up the material aswell. Those are recommendation more specific to the 6061/7075 Laminated aluminiums, but it also applies to the casted one.
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Some people have suggested using vegetable oil + water.  I haven't tried this yet.

I use the TiNi (I THINK) stuff on my step bits, and they still get aluminum stuck on them quite often.  I'm constantly having to pry off the 'melted' aluminum.



there's also something to be said for reading the owner's manual for your drill press and choosing the appropriate speed setting for the material you're working.
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What's the difference between using iso mixed with water and just plain water for heat dissipation? I didn't think iso had any lubricating properties at all.


isopropanol should have a better wettability of the surfaces, but I would guess that water should do the trick too. it doesn't evaporate near as quickly though...
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Good tip.  Last time, I used WD-40.  It's a bit greasy but it's easy to clean up.
I wasn't using any lubricant for a while, but the aluminum I was cutting wasn't very hard.
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Nice tip.

I use 99% ISP for flux removal, now one more use for it.
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Good tip Ben!  I resharpen my step bits.  I've been using the same 3 bits for 6+ years.  The fluting on the bit is quite large so its easy to get in there with a flat file and resharpen the edge.  Works for me!
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Cutting compound/paste is really handy.

You can buy Rocol cutting paste and hand apply it to your bit before drilling:

Makes a huge improvement on cutting and increases tool life.


Funny, I've been using the iso alcohol for years to clean my enclosures after drilling. Not once did it dawn on me to use while drilling. Great tip.


I don't know if I'm just using some extra soft enclosures, but I have a drill press plus a set of cheap brass coloured stepping bits (I think I paid $5 or $10 for a pack of 3) and it just goes literally like butter with no lube. It doesn't make metal spirals either like the 1/8 inch aluminium synth panels I used to drill. It just turns the aluminium almost to dust.