Section 5 Deburing Instructions

[ALCpilot]

Hello,

I am new to the community, so excuse me if this has been discussed before; however, I couldn't find a post. I have been working on the practice kit included with the RV14 EMP kit, and I bought a couple of other practice kits before I get my feet wet on the real thing.

While building the practice kits, you go through drilling, match drilling, and deburring all surfaces. However, Section 5 of the builder's manual clearly states the following.

"Van's produces two aircraft kits with the holes punched final size (the RV-12 and RV-14*). No deburring is necessary; dimple
the holes and assemble the parts. These final-sized holes are manufactured using specific tooling and tight tolerances to work
with all commonly available dimple dies. By "work with," we mean that the holes may be dimpled without fear that the hole would
crack prematurely before the expected fatigue life of a conventionally drilled, deburred, and dimpled hole."

Would it be proper to think that no deburring will be needed for the 14, and is this the standard practice that everyone is following? Or is this in error thinking that the parts were laser cut and now they arent so we need to go back to deburring again? My father built a 10 and spent much time deburring all surfaces, ribs, and holes.

I would like to hear what everyone who is out there building the 14 is following.

Thanks much! Randy

[Brantel]

I’m building a 12 and I deburr and round the edges of everything.

Just because a hole is punched full size means nothing, there still remains a hard edge and a slight ridge around the exit side of the hole. A quick touch with a chamfer bit makes both go away.

There are also many places on the 12 and 14 where parts get match drilled or holes get upsized. These need proper deburring as well.

Everywhere this is not done is another opportunity for stress risers and future cracks to form.

[BobTurner]

No, the mechanically punched parts were supposed to be final size for the -14. However, I think there were still a few holes that needed to be match-drilled. And, some builders opted to lightly de-bur every hole despite the instructions. Your airplane, your choice.

[mturnerb]

The final-size holes, whether punched or laser cut, may not need deburring. You can judge for yourself when examining a given part.

However, there are still quite a bit of parts that get match-drilled from another part, or drilled specifically to a required set of dimensions, or using a template. Those holes will likely need some deburring.

No experience here with laser-cut parts but my experience was that punched parts typically benefit from some light surface deburring (particularly on the "punched out" (versus "punched in) side, and edge smoothing/deburring....

[n4322b]

You can feel the two sides of a drilled panel and you'll easily detect the burr with finger tips and as others have said I deburr as a routine.

Theres some match drilling but far less than on the older kits.

Ian

[dstates]

For the final size punched part I tend to just lightly debur the "exit" side of the hole. It is obvious which side when looking close or just running your finger over the holes.

Anything else that gets drilled (or is laser cut) should be deburred.

[n4322b]

You can feel the two sides of a punched panel and you'll easily detect the burr with finger tips and as others have said I deburr as a routine.

Theres some match drilling but far less than on the older kits.

Ian

[dstates]

Also, to clarify since your original post talks about deburring all surfaces, you will still need to deburr all of the edges of parts and any holes that are not rivet holes along with what was said about final size holes above.

[MechaSteve]

Additional reasons to deburr parts are:

Safety: Un-deburred parts are like tiny serrated knives. Properly de-burred, they are perfectly safe to handle. They are also less likely to scratch other parts.

Debris: The burr edge is fragile and can break off at any time and leave tiny aluminum crumbs. These can get between parts and cause scratches or be a hazard to electronics.

Because of how parts are manufactured, parts are frequently formed with the burr side on the inside, or against the shop head of the rivets. Some parts that are Left and Right twins are formed from the same blank, and this makes one 'burr inside' and one 'burr outside'.

Also, it looks pretty.

[daveyator]

I believe many people take the wrong attitude towards deburring. Instead of seeing it as a chore, I always used it as a "getting to know you" time with each part. Checking them out and getting them ino the best shape to go into my aircraft. When I had finished, I knew every part, and that is was as good as I could get it.
But maybe I'm just a bit strange.
Cheers DaveH