[Michael Burbidge]

The Standard Aircraft Handbook shipped with the toolkit from Avery says the following on deburring holes:

"Removal of these burrs,..., must be performed if the burrs tend to cause separation between the parts being riveted. Burrs under either head of the rivet do not, in general, result in unacceptable riveting."

What do you think about not deburring holes under the heads of the rivet?

 

[airguy]

It may very well be a case of "The sky is falling", but I'm concerned enough about stress risers starting a crack from a burr that I'm deburring all holes regardless.

 

[craigvince]

Debur them ALL.

 

[docrick]

Note I got with my tool kit from Isham

They send a page explaining that deburring holes with traditional deburring tools is foolharty for thin aluminum like skins.

they say deburring skins with deburring tools for sure enlarges the hole and makes for poorer riveting results.

I agree. They suggest taking a gloved hand and rubbing over the drilled holes on both sides of the skin and this is enough to take off the small burr on both sides of the holes.

I played with deburring on thin scrap and yep unless you don't spin the deburring tool even one full revolution you enlarge the hole if you deburr on both sides.

I've since riveted up the VS and half of the HS and the gloved hand works well and the riveting job looks great (per the EAA counselor).

Careful if you deburr thin aluminum!

 

[Michael Burbidge]

What kind of glove?

That's exactly what I'm wrestling with. If I use a deburring tool or a drill bit in hand, it is very easy to enlarge the whole on thin aluminum such as skins and ribs.

 

[docrick]

That's exactly what I'm wrestling with. If I use a deburring tool or a drill bit in hand, it is very easy to enlarge the whole on thin aluminum such as skins and ribs.

Try the glove it works like a charm and is infinitely faster! If you want to read the comment from Isham go to their web site at www.planetools.com and you will find the comment about deburring skins with a gloved hand.

I notice if you debur the skins with a deburring tool on both sides and then dimple the hole is definitely enlarged.

 

[RScott]

First, go buy AC 43.13 from Van's. This is the Bible for aircraft repair and construction. I am personally not impressed with the Standard Aircraft Handbook but that's just my opinion.

43.13 is dry and has a lot more info than you need, but it has almost all the info you need.

Paragraph 4-58 of AC 43-13 says, "Deburr the hole with an oversize drill or deburring tool."

I think too many people put too much pressure on the deburring bit--I know I did and was half way thru the wings when I learned to go light. Just very light pressure as you spin the tool and one revolution usually does it. Actually, with the 3 flute bit, you probably only need half a revolution. All you want to take off are the burrs; you don't want to countersink the hole, which you will do with pressure. Also, with too much pressure, you leave a new burr.

Here's another approach if you think deburring enlarges the holes. Are you going to prime? Then as you go over the parts with Scotch Brite prior to priming, you'll take off most of the burrs. Just be sure to check before priming.

 

[Hal]

Here's a good technique: Use a right angle drill, set the air pressure on 20 - 30 psi and insert the threaded countersink tool. Just set it in the hole, do not push and give it a light spin. Takes a millisecond - I figure I have deburred aorund 320,000 holes doing this. Get the technique down and the results are fast and good.

 

[tmbg]

You definitely need to get rid of the chips, and if there's enough of a burr that parts won't mate completely, then that's a problem.

HOWEVER, the act of dimpling a hole tends to burnish the inside of the hole enough to take care of any burr, and stress concentrations on rivet holes aren't a particularly big concern. In order for a concentration to become a crack, there has to be movement. Riveted joints don't move. If the rivet works loose, you have bigger issues than stress concentrations.


I'm a fan of the 'gloved hand' method to knock chips off.

 

[Michael Burbidge]

What kind of glove...

Do you guys just use a leather glove, or something with fiber such as a knit, where the fiber might catch the chips more readily?

 

[airguy]

I tried the glove technique last night on my VS skin after match drilling, had several holes that snagged a bit of leather off the glove. I didn't see it at first, just felt a small drag as my finger ran over those holes, but on very close examination of the hole you can see burrs caught a small fiber of the leather on them. The glove was not taking the burrs off - the burrs were taking the glove off. Removing the glove and running a finger over the holes told me quickly I still had raised edges on all the holes and burrs on many, so I went to the 1/4" drill bit in my fingers and that worked great. Very light pressure, couple quick turns, and done. And, yes, before anyone asks, I did happen to use a brand new #40 bit when match-drilling this piece, so a dull bit is not the culprit.

A gloved hand will knock any chips out of the hole, but it's not going to remove burrs or raised edges from pre-punching or match-drilling. Whether or not you NEED to if it's going to be dimpled is another story altogether.

My .02....

 

[docrick]

I use a leather work glove

Do you guys just use a leather glove, or something with fiber such as a knit, where the fiber might catch the chips more readily?

The leather work glove works like a charm. Apply a decent amount of pressure when rubbing over the line of holes.

 

[GAHco]

That's what I do too!

Here's a good technique: Use a right angle drill, set the air pressure on 20 - 30 psi and insert the threaded countersink tool. Just set it in the hole, do not push and give it a light spin. Takes a millisecond - I figure I have deburred aorund 320,000 holes doing this. Get the technique down and the results are fast and good.

It works great. I put the handy swivel dealybob on with a regulator and now I dont make trips to the regulator to adjust the air when I use a tool that has one on it.

or

I also use a really short 3 flute deburr bit.

Quick, easy, and effective.

It will also get in tight places.

CAUTION: Press vey lightly and just a fraction of a second.