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Deburring. How picky?

Outrider

Member
I?ve been putting together my shop and practicing on a couple Vans toolbox kits. The first one I barely deburred at all because I just wanted to get to the riveting part. The second one I hand sanded all the cut edges I could reach with sandpaper. I noticed there were a lot of little nooks and crannies I couldn?t easily reach with any tools without spending an inordinate amount of time.

That brought the question to mind: Just how picky do I need to be about deburring and polishing every single edge? I imagine on the plane, just like the tool box, there are a lot of hard to reach places, like the inside of the tabs on wing ribs, etc.

So, do I need to prepare to spend the majority of my build time hunting down and polishing imperfections in hard to reach corners with a jewelers loupe, or is there a happy medium there somewhere, and where would that be exactly?
 
Sound like you may not have a Scotchbrite wheel ?

I'd sooner cut a good sized lawn with scissors than debur an RV kit without one !

Seriously, if not then it's probably one of the best tooling investments you can make :D

Personally, I try to debur all the edges of all my parts. Once you have the right set of tools this is not too difficult ... but still takes time.

My rough process is

1) Break long edges and large diameter radiuses with a deburing tool (swisstool) or flat file
2) Get into corners with a round needle file
3) Use the scotchbrite wheel to finesse
4) 240 grit abrasive to finish. I know when it's done because I dont feel any risk of cutting myself on the part and cannot feel any nicks or irregularities in the edges.

Use your imagination on where cracks are most likley to form ... but pay very particular attention to critical areas (eg If you do an 'Emp kit 1st then anywhere around the H/S centre section)

As I said, it takes time ...... but you are building an aeroplane
 
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Debur

Something to be said, as well, is that a lot of people overdo the deburring process.

You do not need to polish every edge to a mirror finish, and you do not need to remove a lot of material...

Look at the mainstream GA aircraft that have been flying for 50+ years; run your finger over the inside edge of a lightening hole (carefully)...
 
I do 90% of my deburring on my Scotchbrite wheel. The inside areas of flanges and relief holes are tricky, and for these I use hand tools. I don't go for a mirror finish either, or sand them down, but I do make sure I can run my finger down each edge and not feel any nicks or deformities.

Also, don't use a Scotchbrite wheel on large skins or you'll get this: http://www.vansairforce.com/community/showthread.php?t=156306
 
I think somewhere in the Van's manual its says something to the effect of "if you can run your finger across the edge without fear of being cut then its good". I tend to agree with the.

Just round the corners and make sure the edges are smooth. The deburring wheel works great, but so do files, scotch brite pads, edge deburring tools etc. It usually only takes about 1 minute per part.
 
Sound like you may not have a Scotchbrite wheel ?

I'd sooner cut a good sized lawn with scissors than debur an RV kit without one !

Seriously, if not then it's probably one of the best tooling investments you can make


You guys are helping me fill up my shopping cart over at one of our favorite suppliers.

Which grade of Scotchbrite wheel do you recommend? 7A, 7s or other?
 
The funny thing is that the deburring and smoothing should really be done BEFORE Van's forms the parts. Kind of backwards to remove crack initiators/stress risers AFTER bending!
I would pay good money to Van's to deburr the edges of all formed parts in the flat. Those rib and bulkhead notches and corners are a pain.
I'll (somewhat) gladly do the holes and flat part and sheet edges.
 
I bought a roll of 220 grit cloth backed sandpaper. I find that I can quickly sand the edges and you can fold or roll it around things to sand all of the shapes needed. I also bought a bag of small sanding drums off of ebay that I use in my dremel tool to sand the small circular shapes. I do use a scotchbrite wheel too, but usually only as the very last step as a quick pass.

You'll get very quick at sanding edges, then checking for burrs.
 
I generally use files, including a set of small shaped ones, for deburring. A deburring tool with a swivel blade is good for holes. SOmetimes 220 or 320 grit is handy, too.

I like to remove all traces of the sheared edge, leaving good aluminum. After I'd been doing that for a while, I checked my good old Cessna 180 and it has the as-sheared edges. Surprising but there it is.

I don't own a Scotchbrite disk on a grinder, never felt I needed it.

Dave
 
The best investment I've made in any tool was a 3" Vixen file with a wooden block on the back, $10 at the Yardstore.

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It fits perfectly in your hand and you can deburr any straight edge section easily and quickly, just a few strokes and you are done. I usually pull the file lengthwise (parallel with the direction of the edge) down the edge until it is smooth then tilt the file 45 degrees (still parallel with the edge) to either side to pickup any burr left behind. Fastest method I have found for edges and you don't have to worry about a scotch brite wheel grabbing a thin skin edge and putting a kink in it.

For the areas around the corners and flanges where the palm block doesn't reach, get some good quality 220 grit, cloth-backed sandpaper (I like Klingspor shop rolls) and rip a piece about 3/4" wide and 6" long. Put one end over the burr on the flange. Grab that end with one hand while putting light pressure on the sandpaper over the burr with a finger or thumb of the other hand and pull the sand paper through. It will only remove material where you apply pressure so, in this case, pretty much only the burr is affected. Usually, one pull and the burr is gone. Once the paper is worn a little it becomes super flexible and able to get into the tightest bends. Just hold the part in one hand using the tip of your thumb to feel for burrs. When you find one, put the sandpaper over it, press lightly on the burr (through the paper) with your thumb and pull the paper through. It is very fast. You can work your way around a flange corner on a rib in 3 or 4 quick pulls.

I have tried many different methods and these are the two I always seem go back to. I do have a scotch brite wheel on a bench grinder but generally only use it for small, stout parts but even then I touch up the corners with the sandpaper strip. I literally have an entire drawer of 1" scotch brite wheels for a pneumatic drill or cut off grinder that I never use. Live an learn, I guess.

Whatever you choose, I wish you the best of luck with your build.
 
. snip

That brought the question to mind: Just how picky do I need to be about deburring and polishing every single edge? I imagine on the plane, just like the tool box, there are a lot of hard to reach places, like the inside of the tabs on wing ribs, etc.

So, do I need to prepare to spend the majority of my build time hunting down and polishing imperfections in hard to reach corners with a jewelers loupe, or is there a happy medium there somewhere, and where would that be exactly?

I think a lot of RV builders suffer from OCD: Obsessive Compulsive Deburring. Van's says if it won't cut you, it's OK. I agree. The edges don't have to be polished.
 
I do 90% of my deburring on my Scotchbrite wheel. The inside areas of flanges and relief holes are tricky, and for these I use hand tools. I don't go for a mirror finish either, or sand them down, but I do make sure I can run my finger down each edge and not feel any nicks or deformities.

Also, don't use a Scotchbrite wheel on large skins or you'll get this: http://www.vansairforce.com/community/showthread.php?t=156306

Those insides of flanges are what I’m most concerned about. I decided I wanted to build this second box like it was an actual airplane part. When I got home I was brainstorming about how to deburr the inside the corner relief holes. I tried a round file—that was too big. Then I got the idea use my “Shaviv” style tool to knock down the big stuff, but it still left chatter marks, so then I wrapped some sand paper around the shank of a #40 drill bit and went through each of the holes polishing them up. That did the trick!

I think it’s going to come down to building a mental tool box of creative solutions like that and things should speed up once I’ve got a good number of them stored away.

I am really appreciating all the creative ideas you veterans are offering.
 
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The easy way to deburr the edges of skins is to just use a flat file along the edges. A couple of swipes and the jaggedness is gone. Then I quickly ran the edges along a small 1" diameter scotchbrite wheel that was chucked in my drill press. The scotchbrite wheel will get some deep ridges in there eventually and I think I went through at least 3 or 4 of these for the entire build. It polishes the edges very nicely.

Deburring the match drilled holes is tedious, but necessary. I used the simple deburring tool and just a single twist is all that is necessary to trim off any burrs from the match drilling.

The flanges on ribs are probably the most difficult and time consuming to deburr. Lots and lots of little nooks and crannies to smooth out. Emory cloth works fine here.

You don't need to over do anything, just make it smooth enough prior to riveting to eliminate any stress risers.
 
Anybody work in a jet factory? I had a tour of the Boeing plant recently, and the old GD plant in Fort Worth a long time ago. I wish I had asked how they debur their wing ribs and such. I doubt they are using cloth backed sanding material or dremels! I also doubt I have the $$$ to replicate their process.
 
More training required

One of the first tasks on the -8 HS is to take the sharp edges off the rear spar reinforcement bars. Since everybody says the 3M wheel is fantastic for this type of chore, I gave it a ?whirl?. Result... a bar full of tool marks from the wheel. Arrrgh! Haven?t used it since. What?s the trick to using that d@rn wheel without making more work for yourself?????
 
Gentle application

Most of the time when people have a bad experience with a power tool, it is because they try to force the tool into the work (or vice versa).

Make sure the work is held firmly, but engage the tool with gentleness at first until you feel the wheel start to bite. Also a new wheel will have sharp edges that are prone to grab. Use a heavy piece of scrap to break the edges before using the wheel on a real part.

I also prefer a 2" wheel on a small air angle grinder. There is little rotating mass, so if it does grab there is little energy to deform the part. It also gets into much tighter spots and is less unwieldy than moving large parts to a stationary grinder.

Good luck
 
Proper use of wheel

Can one of you, the ?experienced? guys, post a couple of pictures of properly deburred parts using 6? the 3M 7A wheel?
Thank you in advance.
 
Also, if anybody has links to deburring wheels they mounted in their drill press or die grinder, that would be VERY helpful.
 
I use files. Can use fine for many jobs, course for some of the rough stuff from the factory punches/lasers. I use drill bits for holes use round files of varying sized for inernal curves, crannies, etc.

I shoot for smoth, not necessarilly super smooth, unless the edge will be visible or touched.

Larry
 
Do any of you guys use Cratex products for deburring? When I was a machinist (in another life) we used them all the time. https://www.cratex.com/

What?s the substrate? With aluminum, it?s as much about the carrier or substrate as it is the abrasive. Aluminum ?loads? up readily, that is why Scotchbrite products works so well, they carry the abrasive in loose, open webbed, substrate that allows the material to ?exit?.
This product looks like it might load up easily but I have never used it.
Like a grinding wheel, which works great on steel, It does not work on aluminum.
 
I'm probably in the "deburr more than I need to" category. I too wonder if I'm spending too much time doing it but on the other hand I hear from experienced builders that a big chunk of the build hours winds up being some type of deburring task.

For thin skin edges I run a file over them until the shear marks are mostly gone, then sand smooth with 320 emory cloth and finish with a wipe of scotch brite hand pad. For the substructures, I'll use some form of 3m wheel (6" on the bench, 2" or 1" in a die grinder). Intricate areas like the LE/tank ribs get a flossing with emory cloth and man that took forever. Lightening holes get the small 3m wheel. Everything usually gets a final touch up with a hand pad.

I always struggle to decide if I've deburred a rivet hole enough with my speed deburr tool. light pressure, 1-2 turns is all I do and I seem to always get just the smallest ring of shiny around each hole
 
I use a 90 deg die grinder with 3M roloc type surface conditioning disk (scotchbrite) almost exclusively. typically one pass along the the edge will do the job. I have one of the 3M 7 inch de-burring wheels that I've only used a couple of times. Files and emery cloth are also beneficial in some instances.
 
Scotchbrite won?t take out the punch/shear marks. One pass with a file will. Not sure it is necessary but I am from the school that all ?mill marks? are to be removed. (The Italian?s where from a different school. You can see every drop and path from the mill of the spar caps, but no airframes where ever lost).

?Break? the burred edge with whatever method you choose. You just want the burr gone (finger test).

The bigger issue I see is over de-burred holes. Again, you just want to break the edge, not chamfer the hole.

I have seen a lot of RV?s that didn?t appear to have any edge work done at all. Sharp edges everywhere, but I have yet to see any cracks as a result. I usually see ?other? build issues in those airframes.
Edge treatment is one of the first things I look at. It shows an attention to detail, and one would hope the builder followed suit elsewhere.
 
+1 for 90* die grinder and with 3M roloc surface conditioning discs. I use blue for most applications and maroon to remove more material. It really does a nice job .
 
+2 for 3M Roloc surface conditioning discs. Although I also have 1", 2" and 6" ScotchBrite wheels, I usually start with a file and finish with a blue Roloc disc.
 
I have seen a lot of RV?s that didn?t appear to have any edge work done at all. Sharp edges everywhere, but I have yet to see any cracks as a result. I usually see ?other? build issues in those airframes.
Edge treatment is one of the first things I look at. It shows an attention to detail, and one would hope the builder followed suit elsewhere.

Sharp skin edges also promote micro-cracks in the paint along the edge, which leads to corrosion starting on the skin edges. If you're going to over do it, over do it on rounding the edges of the skins. Paint does not like a sharp edge. I have seen some beautifully painted planes that have corrosion starting along all the skin edges. A real shame.
 
Need breathing protection in my opinion

I used the deburring wheel mounted to a Harbor Freight buffer/grinder. Very happy with the combo. HF buffer/grinder got very hot but thru one build, it still performs as new. Of course, you will want to have fine files, curved ones small and 1/2" size, flat ones, 1/2" and 1' or so. FINE grind. I also used a couple of small rat tail files. Be patient - pay attention to detail - this job is kinda like watching grass grow but very necessary.

I highly recommend that anyone doing deburring operations use some sort of mouth and nose (breathing) protection. After using the rotary deburring wheel for a couple of hours the first day, I began to cough. I imagine that I breathed in a few grams of aluminum filings that first day. Your face mask doesn't need to be expensive - I bought a box of 12 'dust masks' from Home Depot - works well.
 
Where do you guys get your files? Cleaveland used to sell a file set but they no longer do.

I got my vixen file from Avery or some other aircraft tool supply (I forget which, this was 7+ years ago), but the rest of what I have just came from wherever. I have a set of hand files from Harbor Freight, and a set of small and smaller needle files that I believe I got off Amazon. They've all served me well.
 
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