RVG8tor

RVG8tor

Well Known Member
Please excuse the question from the new builder. But nothing I have read addressed my issue. I was deburring the VS main spar doubler (very thick). I was working the lightening holes, with a 1 in scotch bite wheel. The edges felt smooth but when you look at the area there are low and high spots from what looks like the forging process.

My question is do these parts need to be mirror smooth or is smooth to the touch work. Also while deburring my wheel slipped and I managed to scratch the flat surface of the doubler, deep enough that a red scotch brite pad does not remove the scratch, am I correct is assuming that I need to sand these scratches totally smooth. On my edges of the thick material I used a vixun file to get the high spot off, then the wheel to smooth things out.

Thanks for the help, any books with pictures that show what is good and band deburr practice. I took a fundamentals class but we did not deal with thick aluminium like the VS doubler.

Cheers
 
Mike,


Do yourself a favor and pick up a dremel (or knockoff, I have the sears version) tool and get some sanding drums (course and medium grit). These puppies make deburring holes in thick aluminum a breeze. After you get done with the dremel, go over the holes with a scotchbrite pad to polish everything.

If I were you, I would try to remove the scratch. Go to the aviation department at Home Depot and pick up some course and medium grit emery cloth. That stuff eats through scratches. Finish it up with some fine emery cloth and the scotchbrite pad.

Good Luck,
 
Find what works for you

RVG8tor said:
...... .working the lightening holes, with a 1 in scotch bite wheel.....but we did not deal with thick aluminium like the VS doubler.
Click to expand...
Mike,

We all tend to develop deburring preferences. My personal choices are based upon years of production work using just about every deburring tool imaginable. A thing that struck me when I decided to build an airplane is finding that many builders tend to overthink the deburring process. The goal is to simply to "break the sharp edges." In practice, a typical production inspector will simply run his fingers lightly over the work to see if you have succeeded.

Like most production workers, I just reach for a common (1/4" or larger) drill bit to debur most rivet holes.

The photo on the left shows a widely available tool that can make short work of deburring lightening holes. Its (replaceable) cutter swivels about the handle. Simply rotate the tool around the edge of the lightening hole a pass or two and you are done. Spare cutters can be stowed inside its handle, but in practice you can go years without changing one. If you are deft, the tool also deburs straight stock fairly well. Another favorite deburring tool in my collection is shown on the right. Simply place its "V" shaped cutter against the edge of the work and draw the tool towards you to quickly debur the edge of aluminum stock up to 1/8" thick. Its built in hood is a good safety feature.

Not including emory cloth, there are (almost) as many deburring tools out there as there are opinions, so consider the examples shown as merely personal examples one builders' favorite choices.

 
Rick,

So if I understand you correctly, as long as I take the edge off of thick stock AL, line the holes in the VS doubler then I am OK, there is not need to emory, scotch brite wheel the flat surface on the inside of the holes. On the outer edges of this part there are little bumps that look like left over marks from the part cutout process, a simple edge deburr would make the part not have a sharp edge but it would still have a bump, is that OK in your opinion?

Thanks

PS I do have both the tools you pictured in you reply.
 
1" scotchbrite wheels mounted in a die grinder are excellent for doing this.

I would get some now and use them. These work great on skins as well and for doing anything that is not practical on the big wheel. They don't last as long as the big wheel and are not really that cheap. You will also need a mandrel for them. I think Avery sells them.

2000700583163992438_rs.jpg


Mandrel

2003475026293812319_rs.jpg
 
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RVG8tor said:
.... On the outer edges of this part there are little bumps that look like left over marks from the part cutout process, a simple edge deburr would make the part not have a sharp edge but it would still have a bump, is that OK in your opinion?....
Click to expand...
Those bumps are raised areas produced by the factory shearing process. You will see many of them over the course of the project. Good practice would have you remove them. Depending upon the size and shape of a particular part....I remove them any number of ways including (but not limited to) a 2" sanding disk fitted to a right angle die grinder, a vixen or other file, or the easiest way when possible, leaning the bump against a 6" medium scotchbrite wheel fitted to one side of my bench grinder.

 
What I do to make it smooooth.

On outer edges I lightly draw file (move the file sideways instead of back and forth) until the bumps are gone. This is done perpendicular to the sheet edge.

Then I break the edges the same way. This is done at an angle to the sheet edge.

I usually do this with an eight inch fine mill file using a light touch.

Then I run maroon scotch brite pad by hand back and forth until it feels smooth and clean.

In inside curves or holes I clean with the appropriate size sanding drum, then i use a scotch brite flapper wheel on a drill or a regulated die grinder.

The old test is run a silk hankie along the edge, if it catches, go back and finish it.

Some may say all this is excessive, but I want something better than the spam can stamped out models.

To the knowledgeable, we don't want to "Fret" and then "Crack":D
 
Not to hijack your thread, but...

Mike,

Forgive me for diverting the thread, but I bet there's a good story here: how is it that you flew both the F-15 (USAF jet) and the F-14 (Navy jet.)

I'd have sent this as a private message, but I bet others would like to know too.

Cheers,
Martin
 
one more "low-tech" method of deburr

my legally blind father does most of my deburring/edge finishing. the drill goes like this:

8-12 strokes with coarse emery cloth
8-12 strokes with medium
8-12 strokes with fine
8-12 strokes with scotchbrite pad

knocks off those little "ticks" left by the cutting operation in all but the thickest (.125) material
 
johnp said:
my legally blind father does most of my deburring/edge finishing. the drill goes like this:

8-12 strokes with coarse emery cloth
8-12 strokes with medium
8-12 strokes with fine
8-12 strokes with scotchbrite pad

knocks off those little "ticks" left by the cutting operation in all but the thickest (.125) material
Click to expand...

Good that you and your dad are working on this together.

Even better that there is a job he can do with his "Disability". I suspect that he gets a lot of satisfaction from helping you.

Count your blessings-----------
 
My varied flying career was due to me not wanting to do the same job for very long. I was flying the F-15 and up for re-assignment. One option is to do an "Exchange Tour". We have these with the Navy and many other countries. I applied and was selected for an F-14 assignment out of Oceana NAS, Virginia Beach. This Air Force guy ended up with not quite 100 landings on boats. It was one of the more challenging things I have ever done. I expected to get some time in a trainer, A-4 or T-2 at the boat. But no, I did the main F-14 school and the first time I saw the ship was in the F-14, and the RIO, (guy in back) has no stick and throttle. I really felt for that guy, I figured the RIO's all drew straws to see who was going to go with the Air Force guy to the ship. Well I must brag and say I completed my initial qualification with flying colors, 10 day and 6 night trips with no bolters (misses).

On a side note I had a friend go fly the Mirage F-1 with the French AF by mistake. He called the assignment guy to volunteer to fly the Tornado with the British AF and the assignment guy input a number incorrectly. My friend received a call telling him he was selected for the exchange assignment and that he would start 6 weeks of language training before he reported for the assignment. Puzzled he inquired why he needed language school to go to England, it was then he learned of the mistake, but decided to take the job with the French. They apparently speak French inter-flight and after just 6 weeks of training his French skills were not the best. There was a lot of just hanging on the wing hoping it would all turn out right.

I hope this answers the questions.

Cheers
 
Thanks, Mike

Mike,

Thanks! I knew there was a good story lurking in there, and you didn't disappoint.

Martin
 
Mike,

For what it's worth, the tools Rick shows I find to be very unsatisfactory for me. When pretty far along on the wings, I finally found a place where the one with the swiveling cutter works: deburring holes such as lightning holes. Works great on holes up to half an inch, maybe larger. Otherwise, for me it just chatters & leaves a rougher edge than I started with. Apparently, since Rick likes it there is a technique to it I haven't found. The vee shaped cutter smooths the corners, but you still need to smooth the edges.

For straight edges I start with a file & follow up with a maroon Scotch brite pad wrapped around a block. For larger holes and inside curves I use a Scotch Brite wheel. Be aware, however, that the wheel can quickly develop a groove & you end up taking the Aluminum coating off the face of the material, which you really don't want to do.

Doing NDI work for quite a few years, we found cracks most often going from rivet holes to edges and less often from one rivet hole to another. This has given me an appreciation for smoothing the edges pretty well. Some guys almost polish them, but I suspect it is overkill. I just check, sometimes with a hand lens, to make sure I remove all the factory nicks.

Richard Scott
RV-9A Fuselage
 
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