Originally Posted by olley
Hi thats what I would use, make sure its sharp and the drill bit is as well, run it at a slow speed and it should be ok.
I used a 32mm one to fit mine and stew's Maxview dish.
Sorry Olley, disagree (partially
Yes, make sure the drill bit and cutter are VERY sharp.
But...... NO, do not use slow speed when drilling a hole through THIN alluminium material.
Your roof will probably be 20swg (.036"/0.09mm) alluminium skin (or there abouts).
If you drill slowly through this material, odds on, as the teeth break through the other side, they will grab and rip the ally, ESPECIALLY if you apply too great a pressure.
Use a VERY fast speed and VERY light pressure and allow the cutter to take itself through the ally. This way you'll get a much neater finish and less chance of grabbing.
..........least, thats how we build aircraft