[WingedFrog]

On one hand there seem to be a class of sheet metal builders who will deburr, no matter. On the other hand, the RV12 manual does not assume that you deburr all because why would they tell you, like page 07-03 step 4 "Deburr the trimmed edge" of the rudder rib that you just cut? I noticed this in several places already and I am left wondering. Specifically in the current section on the rudder, the only mention of deburring the ribs is the one above. Should I deburr the ribs anyway?

 

[KatieB]

On the other hand, the RV12 manual does not assume that you deburr all because why would they tell you, like page 07-03 step 4 "Deburr the trimmed edge" of the rudder rib that you just cut?

"Edge of the rudder rib you just cut" is the answer. If you cut or drill anything yourself, you have to deburr it, unless you have one of those fancy water-jet cutters that leave no sharp edges... Van's tells you to do it there because it's critical to deburr a cut edge. I think it's just assumed that you should deburr anything that feels rough or sharp. That's one of those things that separates a pretty airplane from an *ugh...* Van's parts are pretty smooth, but I've never heard of a reason not to deburr something or at least run some scotchbrite over the edges. Maybe some of the more experienced builders will know more.

 

[engineerofsorts]

I must be a cronic deburrer

Except for smaller width straight cuts the fit into Van's big-mama shears, you will generally see the stepper shear marks about every two inches, with a tiny barb where the shear steps. I was told by my beloved tech counselor to run a file along such edges to get something reasonably smooth, and then do some more traditional deburring with the deburring tools, finishing off when your favorite abrasive. I'm enough of a klutz around the shop that I like to smooth out any piece of metal I'm going to have to handle. I also deburr the burr-side of the punched holes if they are on the manufactured side of the rivet--maybe overkill, but I'm not intending to set any construction speed record.

 

[Geico266]

From a purely aesthetics stand point, be careful deburring the exposed corners of parts. If you put a radius on the part make sure the matching exposed part has the same radius. I've seen a few planes where they did not match. Most would not catch it, but most builder do!
As far as deburring the parts, I chose to deburr every edge until smooth to the touch. 1" & 2" Scotch bright wheels on a right angle die grinder. A 6" Scotch bright wheel on a bench grinder & hand pads make up the bulk of the deburring tools needed. The parts look better and are lighter. They will last longer, and less likely to cut you if you brush against it. JMHO.

 

[Mich48041]

Debur or not?

An A&P told me that he always thought it was important to deburr, until he crawled into the tail cone of a factory built airplane and noticed that nothing was deburred. The theory is that aluminum will will crack unless the edge is smooth, kind of like plastic wrap that is strong but will tear once a small cut is made. That theory might apply to highly stressed parts like a propeller. But how many airplanes have crashed where the governments determined the cause was sheet metal that was not deburred? A friend of mine did not deburr much on his plane and it is flying (so far). There was a professional builder at OSH this year with his completed RV-12. He claimed that he built it in 32 days. I think that I spent at least 32 days just on deburring my plane. LOL The very minimum that I would do is deburr any edge that comes in contact with adjacent parts. And for safety and appearance, deburr any edge that is likely to be touched. If I ever build another plane, I would still deburr, but not to the extent that I did on this RV-12. I over did it at first and probably wore away some alclad that I should not have. I think that each builder will build in a manor that they are comfortable with. Do a good job without spending an excessive amount of time getting every edge as smooth as possible.
Joe

 

[WingedFrog]

Thou shall deburr wisely...

Is my conclusion for this thread. Thanks for your advices full of wisdom

 

[rgmwa]

Larry

1" & 2" Scotch bright wheels on a right angle die grinder.

Larry, I'm finally starting on my build, and was looking at die grinders over the weekend. Just curious as to why you nominated a right-angle grinder as opposed to a straight one. Does it make much difference?

 

[gblwy]

Die Grinder

I'm not Larry, but I used my right-angle grinder a lot. Went through 4 one-inch scotchbrite wheels. Also bought two-inch ones but never used them.

Cheers...Keith

 

[rgmwa]

I'm not Larry, but I used my right-angle grinder a lot. Went through 4 one-inch scotchbrite wheels. Also bought two-inch ones but never used them.

Cheers...Keith

Thanks Keith. I've got the wheels, but was just wondering which type of grinder to get - straight or right-angle.

 

[Yen]

Deburring

The theory is that non deburred edges will crack because of stress concentration, but I cannot see that there will be enough stress outside of a row of rivets, except where there is minimal edge clearance.

 

[joedallas]

On one hand there seem to be a class of sheet metal builders who will deburr, no matter. On the other hand, the RV12 manual does not assume that you deburr all because why would they tell you, like page 07-03 step 4 "Deburr the trimmed edge" of the rudder rib that you just cut? I noticed this in several places already and I am left wondering. Specifically in the current section on the rudder, the only mention of deburring the ribs is the one above. Should I deburr the ribs anyway?

You are building a $100,000 + Airplane.
You can't deburr latter.

My vote Deburr all sharp edges.

Joe Dallas
www.joesrv12.com

 

[Geico266]

Thanks Keith. I've got the wheels, but was just wondering which type of grinder to get - straight or right-angle.

Seriously, I would get one of each or you spend hours changing back and forth. For the price of a new one at Harbor Freight ($12) it is money well spent towards saving time.

 

[scberry]

Deburring

I think deburring can be over done. Most of the parts, skins included, were quite smooth. Most of the parts from Van's only needed deburring on one corner of the edge. The edge that was down when the die or the shear cut the metal. The other corner for the most part didn't need any deburring. I used 80 grit emery cloth exclusively. Even on the sharp edge, don't over do it! Just deburr until you can run your finger over the edge and not feel like it will cut you.

 

[rgmwa]

Die Grinders

Seriously, I would get one of each or you spend hours changing back and forth. For the price of a new one at Harbor Freight ($12) it is money well spent towards saving time.

Thanks Larry. We don't have Harbor Freight over here in Australia, but it must be great place. You guys in the US are always talking about it