Alluminium cuting fluid

WD40 works well for most aluminium alloys, both for turning and tapping

Andrew

Ta .... I have a gallon of, I use it for de-watering ... it's good for that. Funny that it's bought by many for anti-rust or dismantling and its not that good for those tasks.

I prefer Duckoil, does a far better job than WD40 IMO at keeping rust off and seems a good lubricant for aluminium cutting as well. I buy it in the gallon size and use a trigger spray applicator although it can be bought in aerosol it works out more expensive. I mentioned it to someone I know that used to use WD40 and he is a convert.

For years I have used kerosene (parrafin) mixed with a little non-sulfur containing cutting oil. The type used for general metal cutting. I then switched to "Lamp Oil", where in the US is basically deodorized kerosene. Works as well but doesn't stink. But if you only have a few holes to do and WD-40 hanging around then it will work fine. And in small doses doesn't stink. Eric

WD40 is fish oil with a perfume added to get rid of the stink .

Alcohol works nice on blind holes with easy clean up and chip removal. Why the coarse threads over fine???

Wd40 is simple to obtain and still has the same hydrocarbons it used to. White spirit has been got at by the elf of safety, v and is no longer bad for your skin, which means it doesn't work as well...

Any light oily fluid will work ime. I think I used trefolex last time as it was handy.

Dave

Wd40 is simple to obtain and still has the same hydrocarbons it used to. White spirit has been got at by the elf of safety, v and is no longer bad for your skin, which means it doesn't work as well...

Any light oily fluid will work ime. I think I used trefolex last time as it was handy.

Dave

I have read in several sources that WD40 is White Spirit with a small % of mineral oil (which explains why it is good as a cutting fluid for Ally) Don't think it's fish oil.

There are 3 existing tapped holes that are UNC just adding 2 more so they need to match .... maybe it is thought UNC is a better thread for holding in 6061.

The item is US marine industry, and UNC does seem to be the most common thread in US Marine .... Mercury & Mercruiser engines for example all use UNC.

Fine thread just gives more threads and is easier to tap, but if you're tapping half inch down you'll have lots of threads. Also if you are going to use a pilot drill you might want to look into dubbing the 5/16 drill so it doesn't want to screw into the the pilot and brake the drill.

I myself just like fine threads for aluminum, but I mostly did thin stock.

jim a

I have no idea what that means, can you explain further.

It's grinding the cutting edges flat so it doesn't screw into the hole, here it is shown at this youtube link, trust me a sharp small drill not dubbed like your 5/16 may break or f'up the hole if you use a pilot hole. I'd grind small flats on the cutting edges and do a test hole on scrap first. We call that dubbing a drill in the states.

Thanks for explanation .... these are not thru holes .... not sure if that is relevant I was always under impression that you keep your drills sharp ? never seen this before.

The dubbed drill is still sharp, just has a small flat lip much like on a concrete drill bit. Experience is the best teacher, try on scrap first no matter how you do the drilling. Oh, the reason for the oil is so the aluminum chip doesn't bond to the drill, not so much as a coolant, so be sure to use it. Best of luck and please report back. lol

Whale oil be blowed! (I'd never heard of the fish hypothesis)