Phil

Well Known Member
Hi Everyone,

I'm moving on to the Rudder and I'm a little nervous about deburring the holes in the rudder skin. The control surface skins are very thin and I'm trying to figure out the safest way to debur it.

I feel like I've got a couple of options.

1) Go ahead and debur both sides of holes (as I normally would). Just be really easy with each hole.

2) Only debur one side of the skin. (The side with the burr's).

3) Don't use the deburring tool, just swipe the holes with 3M Maroon pads and remove the jagged burrs.

4) Combine 2 & 3. 3M on the outside and Deburr tool on the inside.

Before I screw something up, I'd like to get a little advice on others experiences and how they would do it again.

Phil
 
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Try 120 grit Emery cloth. A good sized roll is only 5-7 bucks at your local plumbing supply. They sell the good stuff.
 
Using a sharp drill helps to keep the burrs down. A couple of twists with the deburr tool should do.
 
3) Don't use the deburring tool, just swipe the holes with 3M Maroon pads and remove the jagged burrs.

This was what I did and it seemed to work OK - keep in mind my 7 is not flying yet...

I found that a few passes over each hole followed by a swirl of a maroon pad pressed with my thumb worked really well. The first few holes that I tried to do with my deburring tool seemed to get bigger even when I just did one light revolution on each side.

Somewhere in the red book, Standard Aircraft Handbook I think it is officially called, it says that you don't even need to deburr things that are going to be form-countersunk (dimpled). I always do it anyway though.

Edit: Bottom of page 87, Sixth Edition Standard Aircraft Handbook for Mechanics and Technicians: "Deburring shall not be performed on predrilled holes that are to be subsequently form countersunk."
 
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I use the debur bit in the extension ONLY and do one light turn on each side of the skin. Don't freak out when you dimple and the holes are enlarged a little - this is the nature of the beast with thin skins.
 
I used method #3, maroon scotchbrite. I stacked 3 round pads on a drill arbor. This also served to scuff the surface before priming.

sanding, filling, sanding, filling, etc. (windshield fairings)
Steve