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The basics....deburring

So I'm beginning to feel like a huge dummy here. I'm spending AGES deburring parts, and I can't help but think I'm doing it wrong. So before I spend even more time on this, can you guys and gals give me some tips? I have at my disposal:

Edge deburring tool
Bench grinder 3M wheel
2" 3M wheel
1" 3M wheel
Dremel
Red Scotch Brite pads

I'm still extremely fresh to the game and haven't actually riveted anything yet, so I have time to fix my methods. I guess my questions are:

1. On a smaller part like a rib, what steps do you take to deburr it?
2. On a larger part like a spar, what steps do you take to deburr it?
3. On a part with lots of little flanges in it, what steps do you take to deburr it?
4. When using a deburr wheel, are you running the part across the wheel on both faces or just straight down the edge of the part? Or do you run it across both faces and the edge?
5. Same question, but with the edge deburr tool
6. What about lightening holes?
7. What about thicker parts like the rudder horn?

I know these are probably super basic questions, but I'm having a heck of a time figuring out what the most effective technique is from googling/youtubing. Additionally, I'm not sure which surfaces of the part are supposed to be deburred (Edge vs face). I'm in no rush, and can keep deburring stuff like I have been - The finishes are butter smooth. But I can't help but feel like I'm not being very efficient, and aside from that, I want to make sure that I'm actually deburring properly.
 
Here's what I do

Deburring can be quick and easy, or it can be a real pain, just depending on the part. Have a read of Van's manual section 5, there's parts in there describing deburring.

What I've found that works for me is:

* most small parts (ribs, stiffeners, brackets etc) will be edge-deburred on the 6" grinder with a scotchbrite wheel. My ginder has two wheels - the higher density one for fairly aggressive cutting, and a lighter one for polishing. Typically I just run the edge along the coarse wheel first, then smooth it all up on the polishing wheel.

* Larger parts like spars, or skins, I will edge-debur using a 1" scotchbrite wheel in an air die-grinder. You've got to be careful with this as it cuts quickly, so keep it moving, and use two hands to hold it steady. Initially I used a 2" roloc disc (purple) in a battery polisher, and it works OK, but the die grinder is a lot quicker. I'll also use a small file to remove the shear marks first, before using the die grinder & scotchbrite wheel. It also really helps to clamp the piece down to the bench, with enough room to move the tool over / around the edge

* hole deburring is a different thing, and there's plenty of threads about how to do that.

* for ribs etc with lots of small flanges, I use either a warding file, emery cloth, or a little detail sander with a fine grit paper. Sometimes cutting a thin (1" ) wide piece of scotchbrite pad works also, and you just rub it between the edges at an angle until things are smooth.

* typically I don't debur faces, unless there was a ding or mark there that warrants a bit of attention.

* for lightening holes I found the 1" or 2" scothbrite wheel in the die grinder is the go. Just zip it around the hole 2 or 3 times and it's as smooth as an infant's behind.

The general rule of thumb is if you can feel the burr when you run your finger over it, there's still more to go. however be careful, you don't want to take too much off, just the burr itself. Obviously machining & shear marks on the edges must be removed as per what Van's say.
 
...and

...and try not to overthink it...there are many, many certified aircraft out there that have been flying safely for the better part of a Century, that have little or no deburring at all...
 
I really appreciate you taking the time to write all of that out, Geoff! Thank you! I'm glad you do the lightening holes like that - That's what I had come up with and it seemed to be working, so nice to get a confirmation there. I don't see you mention the edge deburring tool anywhere in your post - Is that a tool that you just don't use / don't see a need for?

My main point of confusion is this: I don't know what I'm supposed to deburr. For instance, you say the small parts you edge deburr on the grinder, and that you just run the edge along. This is what I have been using for those parts as well, but it's not clear to me if I'm supposed to be running just the edge against the wheel (IE like perfectly perpendicular to the wheel) or if I'm supposed to run the edge through twice (First tilted left, then tilted right) to get both sides.

I know these are probably stupid questions, but I don't see this specifically called out in section 5, and it's better that I learn now rather then 2000 hours from now....
 
...and try not to overthink it...there are many, many certified aircraft out there that have been flying safely for the better part of a Century, that have little or no deburring at all...

Believe me, every step of this process so far is me telling myself not to overthink it. I'm a classic sufferer of analysis paralysis.
 
I really appreciate you taking the time to write all of that out, Geoff! Thank you! I'm glad you do the lightening holes like that - That's what I had come up with and it seemed to be working, so nice to get a confirmation there. I don't see you mention the edge deburring tool anywhere in your post - Is that a tool that you just don't use / don't see a need for?

My main point of confusion is this: I don't know what I'm supposed to deburr. For instance, you say the small parts you edge deburr on the grinder, and that you just run the edge along. This is what I have been using for those parts as well, but it's not clear to me if I'm supposed to be running just the edge against the wheel (IE like perfectly perpendicular to the wheel) or if I'm supposed to run the edge through twice (First tilted left, then tilted right) to get both sides.

I know these are probably stupid questions, but I don't see this specifically called out in section 5, and it's better that I learn now rather then 2000 hours from now....

I did buy an edge deburring tool, and I used it initially, but I've just found other ways that are quicker like the scotchbrite wheel / die grinder combo.

I typically concentrate on the very edge (this is the bit where all the shear marks are anyway) for the initial deburring, then when I polish I usually just run it at a slight angle to clean up the edges. If it doesn't feel rough to the touch, I just move on.
 
Thank you! This is what I've been doing, but I think I've probably been being overly anal about it. On drilled/punched hole deburring, are you deburring just the back side or both sides? I can almost always tell which side the burrs are on very easily, but not sure if it's better to deburr both sides quickly or just the side where the burrs are.
 
I spend way too much time deburring things so if you want to learn how to be more efficient then I don't think this will help much, but here's what I do...

When using the 6" scotch brite wheel, I run the edge of the parts straight down (or up) the wheel parallel to the direction the wheel is spinning in (be very careful not to let the wheel catch the corner of a part...if it does then it could damage you and/or the part). Then I angle it about 45 degrees to each side and give it one more (quick) pass on each of those. Basically it's like I am trying to round off the edges like chapter 5 of the construction manual shows, but I'm mostly just smoothing out the corners where the edge joins the face to make sure it feels perfectly smooth with no sharp spots. This is mostly done with the polishing wheel because the more aggressive wheel is a little too aggressive for me unless

Also, all of that is almost always done using the light deburring wheel that Cleaveland Tool sells. I typically only use the more aggressive wheel on thicker parts like angle pieces that I just cut with my band saw

On thin parts I'll just take them straight to the scotch brite wheel. On thicker parts or large parts like spars and skins, I'll start with a file before using a 1" wheel on an air grinder.

When it comes to parts with lots of little flanges, like nose ribs, I have a very small round file that I sometimes use if there's large burs but a lot of it I do with 400 or 800 grit sandpaper. You can either fold it up into a small strip or roll it up tightly and get it to fit just about any contour in the flanges.

Since you have a dremel tool you might also consider doing this: https://vansairforce.com/community/showthread.php?t=149019
You'll need a lot of extra 1" scotch brite wheels for that though. I use it all the time and tend to go through them pretty quickly. It's worth it to me though.

I've never had much luck with the edge deburring tool. I probably just don't use it very well but it always seems to leave sharper, rougher edges than I started with so it mostly just takes up space in my tool box.

I always use the swivel deburring tool on both sides of holes but one side always needs more attention then the other due to the way the parts are prepunched. Sometimes if space is limited like on the inside of a rib flange I find that it's easier to use a larger drill bit that you spin with your fingers to debur the holes. And if the space is REALLY limited or if the burs are really bad for some reason then I'll use sand paper.
 
Deburring

Obviously deburring practices are almost as personal as, wait for it, Primer Wars!
Basically, find what works for you. The goal is to remove tooling marks and sharp edges.
Slide a finger along the edge. If you end up in the hospital, it needs more deburring!
Files, Scotchbrite wheels, Roloc wheels, scotchbrite pads, whatever works.
 
A few of my tricks:

(Got this one from Vlad): On long straight skin edges, a drywall sanding sponge work pretty well to do initial deburring. I usually follow that up with fine sandpaper or scotchbrite pad or both.

Adhesive sandpaper: (https://www.amazon.com/gp/product/B0000223SN/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1) with soft and/or hard blocks.

Same paper rolled into various size little rolls to fit into nooks and crannies. Same paper wrapped onto small dowels and popsicle sticks.

Abrasive cord (https://www.amazon.com/gp/product/B000REGVES/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 or similar) for really tight corners and tight spots.

I also like emery cloth but use it less than other methods mentioned.
 
In the sheet metal workshop at Oshkosh, we only give the students a mill file for edge deburring and the swivel deburring tool for drilled holes. A couple sizes of mill files (small and medium), some jewelers files, including round, plus a vixen file.

Maroon scotchbrite pads are good for polishing the edges.

Learn how to debur to smooth conditions with a file first, then use the rest of the tools to polish the edge or get into tight spaces.
 
I am scuffing with a scotcbrite prior to priming. I consider that an integral part of my deburring process. I tend to believe that most are doing way too much material removal in their deburring. As long as you don’t have burrs or chips holding the material apart, you are fine. The idea that cracks form on these parts because the edge was sharp enough to cut your finger on is crazy and I know of no planes that have come down due to lack of deburring.
 
I've seen sheet metal fail (start cracks) because of poor deburring.

Taught by WW2 Factory workers in the 70's This was emphasized.

That said, I agree that novices tend to remove too much material
 
Deburr Tool

I use a 14 year old deburr tool.
All parts slick and smooth with little effort on my part.
:D
 

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I wish I had a 14 year old deburring tool....

Then again, perhaps not! They eat too much!! :D
 
“I've seen sheet metal fail (start cracks) because of poor deburring.”
Can you elaborate?

I can. On aircraft I have inspected concerning Van's service bulletin on the horizontal stabilizer spars; every one that I have found cracks had not been properly deburred.

Of the ones that I've inspected that do NOT have cracks, deburring was done properly.
 
Not properly deburred, as in deburred not enough, too much, drilled holes not cleaned up, edges of parts left with burrs, burrs between riveted parts, shear marks not sanded down? Just trying to get an idea of where the issues are.
 
All of the above describe stress concentrations.

Low tech description follows:

In the design process, as you calculate mass concentrations as you progress through the design, you can evaluate the variation in mass. Variations "focus" stress forces on areas of less mass - (as compared to areas of more mass - a "weakest link of a chain" thing)

Doesn't take much before the forces on a particular spot exceed the "stretch tolerance" of the material in that location and cracks ensue.
 
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