WHY Do Holes Need Deburred? (EP21)

[@johnvansloun7443]

I about died when I saw the VanVan in front of the ejimication board. We're building a CH-750 SD and also have a VanVan. These videos are great! Thanks for doing this!

[@KitplaneEnthusiast]

The Van Van is a great fun bike! I actually sold it to my neighbor and I bought a TW200. The VanVan is actually a better bike I think but I wanted a little more off-road capability that the TDub offers.

[@paulbrunner1818]

Besides the great build, excellent background music 👍

[@davidrobins4025]

I particularly noticed your choice of music on this video. "Leaning, leaning, safe and secure from all..." A melody I learned as a child. Thanks as well for the clear depiction and explanation for the need to deburr to make the best joint possible. I love your attention to detail.

[@wb6anp]

If you rivet with a bur between skins, like you showed, the joint maybe tight till the burr breaks off then you will have a loose joint, also burr are stress risers and can cause fatigue cracks in the part. Same with deburring the edge of the skin, where the skins overlap if they aren;t deburred they can cause a crack the will travel the full length of the over lap.

[@highpointview256]

Hawkertech....Although there was nothing wrong with what was said in the video, the lack of mentioning stress risers was glaring. From what I've learned, a primary reason for deburring is removal of stress risers from the edges of the holes. The stress risers are edge micro imperfections caused by tearing off of the burrs. Drills leave rough edges, even if no burrs. Punched (not drilled) holes typically leave no burrs, but still need to be deburred for utmost best practice. The de-burring not only removes the stress risers but shapes the edge more roundedly or smoothly resulting in a stronger edge. Consequently, I don't think it is best practice to flat file a hole because it only removes burrs but not the edge micro-cracks that are the stress risers.

[@stoldrag85]

Just found this great "squirrel" video. Subscribed, nice.

[@brucekratky7993]

You’d have made the best of shop teachers. 👍🏻

[@novicereloader]

Shop and Economics... "Look what you can do for hobbies if you don't get your girlfriend knocked up in highschool."

[@ultamathule]

Its also a point of stress for the material which could cause a fracture. That's why they stop drill cracks, same idea! Gotta clean em up! Great job sir!

[@MRJSWORKSHOP]

GREAT JOB on explaining deburring! Not deburring or counter sinking to deep could lead in smoking rivets. Like always you go the extra mile, time well spent. ⭐️⭐️⭐️⭐️⭐️

[@johngood3163]

We love the music! We also are impressed with this finished product over what you received. The classroom instruction was especially helpful. It's this kind of clarity that really helps persuade us to follow your lead, because we understand the why.

[@simonbaxter8001]

Great video, great explanation ... apart from the shape of your shop heads ;-) Love you attention to detail, something that is lacking in a lot of builds I've followed since completing my RV and coming from an aerospace engineering background, we need more good practice like this being demonstrated.

[@theworshiptraveler6709]

Great work Mark and an excellent explanation on the importance of deburring.

[@KitplaneEnthusiast]

Thank you!

[@danielbasovitch5087]

Mark, your illustration and explanation of "why we deburr holes" was perfect and right to the point. Allows everyone to understand the concept. I like the new 'EDJIMACATION White Board" Very Cool.

[@phrogdickenson5259]

This was an excellent video! Thank you!

[@onfloat17]

Thank you! As an avionics guy, I never fully understood the purpose of deburring edges and holes.

[@dicel87]

Top shelf workmanship as always.

[@homertalk]

You're really going the extra mile which makes so much sense.

[@terrymartin6779]

Love the early American music, thanks

[@OneKoolDude]

I like that doubler to take up the thickness of the longeron. On this kit there are several instances like Marks example. In fact as I watched other videos on the Zenith kits I got to thinking, if that assembly is riveted then there will be a step / pucker in the metal. Marks fix is not only brilliant but simple.

[@thomasbordelon4149]

Loved the old gospel standard instrumental. Thank you.

[@ultraflightamerica9019]

another reason to deburr is metal fatigue. the burr can create a stress crack after years of operation, if that stress crack occurs in a hidden doubler/trippler it may not be found until its too late. there have been some commercial airliner crashes the NTSB have linked to 'manufacture defect' and when you read the report the manufacture defect in question was in fact a burr that started a crack that went unchecked. deburring the airframe can add years to the airframe's service life, and with as much money as is being put into them, and you have the opportunity to increase it's longevity at this point, why wouldn't you? (there are a couple dozen reasons I can think of, but my frugal butt just sees the $$ it would cost to replace if I didn't do it.

[@BStrambo]

Love the in-depth explanation! I was wondering why as well.

[@wheelerdavea]

I didn't read all the comments so someone has probably already mentioned it, but another important reason to deburr is if not done, where the burr is attached, it is a stress point and eventually will start a crack in the part or skin. Piper Cherokees are especially prone to these skin cracks.

[@flewster]

Great videos. I would recommend though that you use safety glasses with side shields when cutting those aluminum parts on the bandsaw. Hate to see a pilot lose their eyesight. Maybe on any use of power tools when riveting etc..

[@davejoynt6276]

I just love this.

[@Know-Way]

Great explanation. Thanks.

[@johnreed8872]

Hey Mark... Jan from Viking Engines powder coated practically his entire SD . I'm considering the same , it just so happens that a powder coating Co. just opened up not 2mi. from my very rural home. Maybe in your next video you could explain why your doing the parts you decided to do instead of just primer? Thanks again and Blue Skies!

[@keithconrad7893]

Another great job.

[@randomthings2711]

Love the videos Mark! Keep up the great work!! Do you know if the 750 SD can be flown with the doors off? It appears the 750 STOL can however not sure about the SD. Thanks.

[@KitplaneEnthusiast]

Thanks Colin-I really don’t know about flying without the doors. That would be a question for Zenith.

[@randomthings2711]

I took your advice and contacted Roger from Zenith. FWIW the 750 SD is in fact certified to operate with the doors off. Cheers 🍻

[@orbitalair2103]

I really enjoy watching you assemble, prep and now explain stuff. Great job sir. The ZenAir guys have a dvd they made, they took a file, chopped it and mounted it to a wood block to use as a sheet deburring tool. And they KNOW to deburr this stuff, was this an experimental assembly that you got from zenith?

[@fuzzdmedic]

I wa s once showm a rib in a Foland Gnat,i thnik it was, fin rib that was not deburred properly andthe extra pressure it created caused a stress fracture from the rivet hole to the edge of the rib.

[@colmmurphy6380]

Hi Mark, really like the idea of the 'shim' you made for under the flap motor bracket. I think it would relieve shear stress that would otherwise be in that bracket given its being riveted to two components at different levels. That seems to be something that happens a lot with Zenith designs. Would you think that inserting 'shims' in more places is worth the few pounds in reduction of payload? Great build otherwise. I really like your videos and I'm learning a lot.

[@KitplaneEnthusiast]

It depends on how pretty and wrinkle free you want your skins. I'll probably add a shim in a few places, but for me it's not worth adding a shim under every L angle or bulkhead.

[@orbitalair2103]

its a steel part, all the stress is in the skin. It will make the bottom look really ugly from 6ft away, but face it most people are 2000 ft below you, looking up at the sky, so....

[@scottmiller4711]

This is a bit off topic, but have you considered putting access panels (either screws or hinged) on the fuselage sides aft of the baggage compartment? I wish I had put one on each side for access to those items behind the baggage wall. I do a large one in the baggage wall itself but I think it could use more...

[@KitplaneEnthusiast]

Yes I've thought about it but I'll need to wait until more of the fuselage is built to see if/where I'd need an access point. On my Cruzer, I wish I would have made an access panel near the aft pulley that inside the fuselage for the elevator cable. Other than that one location, I don't think any other access would be useful. So I'll see what I might need to get to in the aft fuselage of the SD and add a panel if needed.

[@klm062599]

When deburring you want to leave a slight bevel on the edge for stress relief. Your point about not gouging out too much material is well taken but a 90 degree edge is equally as bad!

[@KitplaneEnthusiast]

Thanks for the comment Joe, but I disagree. A 90 inside corner is a cause for a stress crack, but not an outside corner. The skins are way too thin to have a bevel on the edge of the hole.

[@pa11owner]

You left out a lot of detail, particularly about the rivets themselves which affects why we deburr. Particularly how the manufactured head has a small radius and the burr can start a crack in the rivet. A very slight bevel in the hole edge is good. You didn’t mention that the rivet shank swells during the rivet squeezing or bucking. On the squeezed head , again the burr can lead to cracked heads. Rivets are a loose fit fastener and relies upon the swelled shank.

[@Jeremybaland]

Do you recommend painting before you rivet the skins together? Great song! How do you know you're old school Army? when you wear polypropylene ha ha.

[@KitplaneEnthusiast]

Lol I wish I would have saved more of the military clothing I had instead of giving it all away!

[@jaideld1]

One thing you did not mention is that if you don't debur. overtime ass the burr weakens you get movement under the rivet and then the hole gets bigger

[@KitplaneEnthusiast]

Very true!

[@justinerdmann12]

I am tossing around the idea of a kit built plane. just wondering if there would be any benefit from dimpling some of the holes. You see a lot of flush rivets on cross country planes but have not seen it on STOL aircraft. lot of extra work, just wonder if you would gain anything by it.

[@KitplaneEnthusiast]

No, there would be no benefit to doing this on a Zenith.

[@UncleKennysPlace]

Aren't many/most holes in Zenith kits punched to finished size? What burrs or deformations are you seeing from punching?

[@KitplaneEnthusiast]

Yes most holes are final sized. But they are drilled not punched. Anytime a hole is drilled in aluminum a burr will be created.

[@orbitalair2103]

Vans kits and planes are slick, with flush mount rivets but in addition to deburring ALL the holes you have to dimple and countersink ALL the holes.....an insanely time consuming process.

[@simonbaxter8001]

... and if you don't deburr before dimpling, you crack the skins! Ask me how I know ;-)

[@ransrb7126]

What model # is the Ryobi Bandsaw you are using? Thanks for very informative videos.

[@KitplaneEnthusiast]

I’m not sure. I bought it at Lowe’s or Home Depot about 10 years ago.

[@ransrb7126]

@@KitplaneEnthusiast Thanks Mark. I looked at the current Ryobi at HD and I'm not excited about the quality. Just looking for a good basic bandsaw for cutting aluminum.

[@carlmccall7198]

I use a bandsaw from harbor freight.. doesn't have to be a high quality saw.. your only cutting aluminum... and i use just a plain ol wood blade.. itll cut through thick aluminum like butter

[@RudyRohr]

Safe and secure from all alarm.

[@Ebbrush3]

you need a combo belt disk/sander

[@dennismortenson4639]

What primer are you using?

[@KitplaneEnthusiast]

Dupli-Color on the skins (because it has a larger fan spray pattern) and Rust-Oleum on the other parts. Both are self-etching primers.

[@jackcreeks7234]

professor proton

[@KitplaneEnthusiast]

Would I be the Bob Newhart version, or the Will Weaton version??

[@jackcreeks7234]

@@KitplaneEnthusiast Mark- question , what is your real profession by trade ????

[@KitplaneEnthusiast]

@@jackcreeks7234 Retired Air Force mechanic, current airline captain.

[@maxaircraft]

Welcome to the my chanel))))))

[@KitplaneEnthusiast]

Pretty cool project! Did you add the extra stringers to the fuselage sides?

[@anthoinealbert7966]

First like!!!

[@gregorygehrke1850]

Bob Ross better watch his ass. There’s a new sheriff in town.

[@KitplaneEnthusiast]

LOL! Soon I'll be drawing happy little trees...

[@GoingToGenocideSLK]

Is the skins made from Alclad aluminium sheets?

[@KitplaneEnthusiast]

They are 6061

[@GoingToGenocideSLK]

@@KitplaneEnthusiast Only worked with 2024 Alclad - so was really wondering if 6061 had similar corrosion protection or if the alloy is just less prone to corrosion? Btw great channel!