deburring firewall

[prkaye]

I went to deburr all the freshly drilled holes in my firewall last night, but then realised that the stainless steel would likely dull my deburring tool very quickly (that little countersink cutter on the hand deburring tool that you spin around in the hole). So I ran a scotchbright wheel in my hand die-grinder over the surface of the holes a few times. This did an OK job, but the edges of the holes are still a bit sharp.
What have other people done about this?

[tinman]

I used a conical grinding stone in a drill motor. I hate working with stainless...

[fl-mike]

For smaller holes you can use a step-drill / Unibit. Get it (a step) to bite into the burr and run it VERY slowly. It will peel the burr off. Big holes are just a pain. I also use a grinding stone in a Dremel or similar. I hate that smell.

[thallock]

I used the same tool that I have used for the whole project--countersink bit in an electric screw driver. I have several countersink bits, and the deburring bit is always in the screw driver, not used anywhere else. I have no idea if it dulled the bit at all. There's not that many holes to do.

For the edges, I used my files, same as every else.

Tracy.

[kentb]

And replaced it. It was about time anyway.

Kent

[briand]

Used my deburr tool as well. Didn't notice it get any duller.

[mike newall]

Just been doing it today - braying holes in for eyeball pass through for the mixture !

Small holes, the stepper drill is good - slowly, with lube.

Larger holes, particularly above 1/4" try a small cut off wheel in a dremel at 90 degrees - light touch, goggles on, works really well and leaves a smooth finish.

The new support for the throttle and mixture from Vans works really well on a vertical IO-360, lined up perfectly, makes a change !