Thin plate or sheet aluminum works 100% fine without cutting fluid. With sharp tools, you're not in it long enough to produce much heat.
I work mild steel at less than 1/4" without oil/CF usually even with HSS tooling. Stainless is another story. Marvel Mystery oil is just mineral oil with an added solvent and works well in steel or aluminum but may be improved for Al use with a bit more solvent to thin it. Mineral spirits.
I work mild steel at less than 1/4" without oil/CF usually even with HSS tooling. Stainless is another story. Marvel Mystery oil is just mineral oil with an added solvent and works well in steel or aluminum but may be improved for Al use with a bit more solvent to thin it. Mineral spirits.
I second the suggestion for "Noga" style deburring tools. They cut only as much as you want them to, and are factory-sharpened quite well so that the risk of accidentally gouging due to use of high force is fairly low.
Another alternative that you may want to evaluate is to put a conical sanding bit ("abrasive cone") in a tool holder or chuck extension and simply hand-spin until the desired amount of material removal is done.
I don't personally recommend the use of multi-flute chamfering tools. I have a 5-flute version that is still fairly sharp but only seems to be able to mush material into the hole unless very high axial force is applied.
Another alternative that you may want to evaluate is to put a conical sanding bit ("abrasive cone") in a tool holder or chuck extension and simply hand-spin until the desired amount of material removal is done.
I don't personally recommend the use of multi-flute chamfering tools. I have a 5-flute version that is still fairly sharp but only seems to be able to mush material into the hole unless very high axial force is applied.
Burrs are largely tearing of the aluminum itself. Sharp bits that are well lubed leave fewer if any burrs. Drill through onto a sacrificial hard wood surface moving it on every hole to get a fresh surface helps on blow through on the back side. A softer surface won’t prevent the aluminum from pushing out instead of cutting. Another idea is to make a sandwich of a sacrificial layer of aluminum on each side of the workpiece clamped tightly together. The workpiece in the middle will be burr and blowout free. It’s wasteful but it does give great results.