YT YouTube2Text

YouTube2Text → Transcripts → The Weird Physics of Sandpaper (Why You’re Working Too Hard)

The Weird Physics of Sandpaper (Why You’re Working Too Hard) — Transcript

by Five Duck Studio · 3,856 words · 613 segments · language en · Watch on YouTube

Open in transcriber Summarize with AI Download SRT/VTT

Full transcript

0:00Yes.
0:01This has everything to do with
0:03sandpaper, but more importantly, where
0:05does the packaging end and reality
0:07start? 4 years ago, the internet crowned
0:103M Cubitron the undisputed king of
0:12sandpaper. Flash forward to today. We've
0:14been flooded with new contenders, crazy
0:16prices, brands hiding behind asterisks,
0:19and a sneaky marketing word to sell you
0:20imaginary specs. But, are these claims
0:23real or trap slowly sabotaging hours of
0:25your hard work? Nobody is sponsoring
0:27this video. I bought every contender in
0:29this ring myself.
0:31One of these is mathematically stealing
0:33from you. The other is a hidden gem that
0:35I don't think anybody's talking about,
0:36but
0:38which is which? And is 3M still the
0:40king?
0:40>> LET'S GET IT ON.
0:45>> I'm not going to beat around the bush
0:46and make you wait for an answer. 3M
0:48Cubitron is still the undisputed king of
0:51speed, but just like hitting a small
0:52town speed trap, going too fast can cost
0:55you. The top three for value, that's a
0:58different story. A random brand on
0:59Amazon technically won. But, before you
1:01click off to buy anything, you need to
1:03understand the damage that 3M leaves
1:05behind and why that Amazon value winner
1:07is a complete
1:09illusion. To get these numbers, I didn't
1:11reinvent the wheel.
1:17I followed the exact scientific
1:18methodology built by Mike Taylor,
1:20verified by Katz Moses, and pressure
1:22tested by Project Farm. I used a
1:24standard DeWalt sander, a red oak board,
1:27and an outlet timer, punishing each
1:29brand's 120 grit disc in 5-minute
1:31intervals for a brutal 35 minutes. Why
1:3435 minutes? We'll get there.
1:41Oh, and I strapped an 8-lb weight to the
1:42top, almost hitting the industry
1:44standard of 11 lb of downward force.
1:46But, here's the catch. These numbers are
1:48completely useless if you don't know
1:50about P-grade, the actual rocks being
1:52used, or the backing holding it all
1:54together. Because assuming all rocks are
1:56created equal is exactly what they want
1:58you to think.
1:59>> May I
1:59>> your attention, please?
2:03>> A higher price tag should mean higher
2:05quality, but often that's just a brand
2:07tax. When you strip away the fancy
2:09packaging, all you're left with is
2:11rocks. Tiny little rocks glued to a
2:14backing with resin and a little
2:16electrostatic wizardry.
2:18So, what do these numbers actually mean?
2:20I'm glad you asked.
2:22Let's debunk the myth that the grit
2:24number means rocks per square inch. If
2:26120 grit meant 120 rocks per square
2:28inch, your sandpaper would be 99% bald.
2:34That number actually refers to the
2:35screens that sort the grit size.
2:38It's literally the number of holes per
2:39linear inch in the sorting mesh. A rock
2:41that falls through the 80-hole screen
2:43but gets caught on the 120 mesh floor is
2:46the 120 grit you thought you just
2:48bought. But, here's the plot twist. That
2:50120 grit label is built on a bell curve.
2:53Most of the rocks are 120, but a few
2:56rogue boulders are allowed to slip
2:57through. Under US standard, 65 to 70% of
3:00the rocks actually have to hit that 120
3:02grit target with an allowance of up to
3:055% for oversized boulders. This is where
3:07the letter P comes in. That P means the
3:10disc follows a stricter European
3:12standard called FEPA. It has a tighter
3:14bell curve requiring 75 to 80% of the
3:17rocks to hit the target size
3:19with an allowance of around 2.5% for
3:21slightly oversized rocks. With either
3:23standard, those oversized rocks are one
3:25of the reasons why you should never skip
3:27more than one grit when sanding. But,
3:29don't get comfortable yet. These are
3:31standards, not a global police force.
3:33>> Standing Police Department.
3:35>> That's the SOUND OF THE POLICE.
3:36>> If you buy from a brand that actually
3:38has something to lose, that P on the
3:39back will mean something.
3:41But, if you buy a 150 pack of P-grade
3:43discs for 10 bucks from an alphabet soup
3:45brand,
3:46that P is probably pirated.
3:49Exhibit A. That alphabet soup Amazon
3:51brand technically won our value test,
3:54but that's only because it costs 7 cents
3:56a disc. When it came to actual removal
3:58speed, it was dead last. You'd need to
4:00burn through five of these just to do
4:02the work of one of 3M's 710 discs. When
4:05you factor that in, and the time you
4:07waste changing them out, it is
4:09mathematically the most expensive way to
4:11sand.
4:16Just 10 minutes with the 710 removes
4:18more wood than 35 minutes with [music]
4:20the value winner.
4:29To understand why that cheap paper died
4:30so fast, we have to look at what it's
4:32made of, and it's not sand.
4:35Old school sandpaper was made from
4:36natural rocks, like flint and steel.
4:39>> Flint and steel.
4:40>> No, flint and garnet, and sometimes
4:42quartz or glass. But, if you want to
4:44sand at 10,000 RPMs, you aren't using
4:47natural rocks. They would wear down way
4:48too fast. Today, you're buying factory
4:51forged minerals engineered to survive
4:53the heat, like aluminum oxide.
4:56It's cheap, reliable, and you can throw
4:58it at almost anything. If sandpaper were
5:00a car, aluminum oxide is a Toyota
5:03Corolla.
5:04Up close, aluminum oxide looks like
5:06microscopic boulders. They start sharp,
5:08but as you sand, they wear down and
5:10round over
5:12like a dull pencil. And that physical
5:14dulling is exactly why the 35-minute
5:16test is a death sentence for standard
5:18rocks. You might be tempted to try and
5:20use every single rock on that disc to
5:22save some money, but
5:24the internet's golden rule is that
5:25sandpaper loses 50% of its effectiveness
5:28after about 20 to 30 minutes.
5:31After that, you're supposed to throw it
5:32away, which is why I pushed every disc
5:34to 35 minutes to see if that rule holds
5:37up.
5:38Here is what the numbers show. On the
5:40red oak, the aluminum oxide did exactly
5:42what the internet said it would do. They
5:44removed a decent amount of material at
5:46the start. Well, except for that random
5:48Amazon one, that one is a lemon.
5:52But, the other two actually put up a
5:53fight. Right around the 15-to-20-minute
5:56mark, it starts its fall.
5:58Like clockwork, they lost 50% of their
6:00effectiveness. The internet was right.
6:03Sanding for more than 30 minutes
6:04is a waste of time. But, when you
6:06compare aluminum oxide to ceramic, it is
6:08night and day.
6:10Ceramic isn't a normal rock. It's a
6:12lab-grown super soldier.
6:16Engineered to intentionally fracture as
6:17they wear, constantly exposing new,
6:20sharp edges.
6:213M doesn't print a P on their ceramic
6:24discs. They use a plus symbol. Standard
6:27ceramic grains are crushed into random,
6:28jagged shards.
6:31But, 3M engineered theirs into perfect,
6:33microscopic triangles that sweep the leg
6:35and show no mercy. It's a proprietary
6:38ceramic that they call precision-shaped
6:40grain. That word proprietary is going to
6:42come back to bite us.
6:45That little math symbol translates to a
6:47massive claim. They are basically,
6:49without legally saying it, claiming that
6:51every grit with a plus punches above its
6:53weight class.
6:54For example, a 120 sands just as fast as
6:57a regular 80-grit. But, it leaves the
6:59wood feeling as smooth as the number on
7:00the box said it would.
7:03Like I said before, the only way these
7:05super soldier rocks actually stay sharp
7:08is if you hit them hard enough to break
7:09them.
7:13Red oak is tough, but let's see how it
7:15handles something tougher.
7:17I ran a 15-minute test on hickory, one
7:19of the hardest woods in North America.
7:21Here is our aluminum oxide and ceramic
7:23baseline.
7:25Now, I have to give credit where it's
7:26due. The Toyota Corollas didn't
7:28instantly die. They put up a fight, but
7:30we can see them starting to trail off as
7:32they did with the red oak, losing over
7:3430% of their cut rate. And because
7:36hickory is so hard, the 3M 710 didn't
7:39magically beat its own red oak numbers.
7:41But, after 15 minutes, it was still
7:43holding its own, only losing 14% of its
7:46cut rate. 3M's marketing team has been
7:48spot-on so far.
7:50And looking at the Red Oak timeline, the
7:52data backs it up. That 50% drop-off
7:54rule, it really only applies to aluminum
7:56oxide. Because all the 3M discs only
7:59lost about 30% of their cutting power
8:01after 35 minutes. And that includes 3M's
8:04310.
8:05Which is interesting because the 310 is
8:07proudly marketed as a blend.
8:10In fact, blends across the board showed
8:12up.
8:13>> [music]
8:14>> Well, some not so much.
8:16>> Hello darkness, my old friend.
8:18>> Both the DuraGold purples and the Diablo
8:20SandNet were also under that 50%
8:22drop-off rule after 35 minutes.
8:25Wait, did I just say blend? Yes. Yes, I
8:28did.
8:33If you dig into 3M's actual spec sheets,
8:35710 and the 775 are blends mixed with
8:39aluminum oxide, exactly like the 310.
8:41So, why am I bringing this up now?
8:44Because while the 310 is probably sold
8:45as a blend, the other two aren't always
8:48marketed that way. And this is exactly
8:50where the word proprietary comes back to
8:52bite us.
8:53The US and European standards regulate
8:55the size of the rocks, but abrasive
8:57recipes are considered proprietary trade
8:59secrets. It's a Colonel Sanders secret
9:01recipe type of situation.
9:05From what I can find, manufacturers
9:07don't have to disclose the ratio for a
9:09disc to be called a ceramic blend. And
9:12that's like music to the ears of a
9:13marketing team.
9:15Exhibit A,
9:16Tic Tacs.
9:17They're able to claim to be sugar-free.
9:19A Tic Tac is like 95% pure sugar, but
9:22because a single mint weighs slightly
9:23less than half a gram, legally, they are
9:26sugar-free.
9:28Take Gator for example. It's marketed as
9:30a ceramic blend. The packaging says it
9:32lasts four times longer. But that little
9:34asterisk is doing a lot of heavy
9:36lifting.
9:37Flip the box over compared to our
9:39standard sandpaper. So, not a lie.
9:42From a certain point of view.
9:44But, let's see how these blends actually
9:46stack up. Let's start with Gator. I
9:48think bottom of the barrel just about
9:50describes it.
9:51When you factor in the price per disc,
9:53the performance was terrible. Both of
9:55their discs only managed to remove
9:57around 27 total grams. To put that in
10:00perspective, Dura-Gold standard aluminum
10:02oxide actually beat it with 31.2 g
10:05removed. The standout blend was the 3M
10:08310. It removed an impressive 54.9 g.
10:12But, the biggest surprise to me was the
10:14Dura-Gold premium purple line. Both
10:16their film and their mesh performed like
10:17top-tier ceramic blends, hanging right
10:20up there with 3M at around 54 g. Diablo
10:23SandNet also held its own at 51.4 g. The
10:26only thing holding the Diablo and the
10:28Dura-Gold mesh back is the cost per
10:30disc.
10:33The discs that removed around 50 to 55
10:35g. They probably have a solid 30 to 50%
10:38ceramic. But, then you have the discs
10:40that only removed around 30 g. If your
10:42ceramic blend performs exactly like an
10:44aluminum oxide, I'm thinking it's a lot
10:46lower than 30% ceramic. Now, I don't
10:49know that for sure, but for Gator, it
10:51has to be on that lower end. They should
10:53probably add an asterisk next to this
10:54max claim.
10:56But, that's just a theory, a duct
10:58theory. So, 3M 710 is the undisputed
11:01king, and you should just buy 710 for
11:04everything. Throw away your aluminum
11:05oxide.
11:07>> NOT SO FAST.
11:08>> It's time we talk about the speed trap.
11:14Every sanding grit leaves scratch marks.
11:16The goal is to make them so small that
11:18the human eye can't see them. Standard
11:20aluminum oxide leaves a shallower
11:22U-shaped valley, but 3M's triangles
11:24leave deeper, microscopic V-shaped
11:27trenches. To remove material twice as
11:29fast, they have to cut more
11:30aggressively. And that right there
11:33is the trap. Those V scratches can stick
11:35out like a sore thumb the second you
11:37apply your finish. Now, not everyone
11:39runs into this issue. To help avoid it,
11:41let the tool's weight do the work.
11:43Pressing down too much will just drive
11:45those triangles deeper into the wood.
11:47But, if you do get caught by this trap,
11:49there are two ways to fix this. Solution
11:52one is to sand one or two grits higher
11:53than you normally would.
11:56But, finishes like Rubio want you to
11:57stop sanding at 150. You can push it to
12:00180, but anything above 220 starts
12:02closing the wood pores. That brings us
12:04to the second option, the 80/20 rule.
12:09You use a ceramic like the 710 for the
12:11first 80% of the work. This is the stock
12:13removal phase and caps at 120 grit.
12:16After that, you just switch to a 150
12:18aluminum oxide. Boom, trap avoided.
12:22Trap not avoided. Do not collect $200.
12:25Go straight to finishing jail.
12:28You can jump straight to a 150 aluminum
12:30oxide, but you're going to waste a ton
12:32of time trying to get those scratches
12:33out. I prefer a much more diplomatic
12:35approach.
12:36I know this will sound totally
12:37counterintuitive, but when you mix
12:39abrasives, you need to sand twice with
12:41the same grit. Switch to a 120 aluminum
12:44oxide first to level the playing field.
12:46Once those V trenches are gone, you can
12:48safely step up to 150.
12:51And that right there is the start of the
12:52final 20%. Trap officially avoided. So,
12:56here's the thing. Sanding is very
12:57personal. We all sand with a different
12:59amount of pressure, different number of
13:00passes, and for different lengths of
13:02time. You'll have to learn from
13:03experience what works best for you.
13:07>> Danger Will Robinson. Danger.
13:09>> But, while pressure and time are
13:10personal choices, there is one rule you
13:13can't afford to ignore.
13:15That 20 to 30-minute expiration date on
13:17aluminum oxide is not a suggestion, no
13:20matter what your mama says.
13:24A dead disc is only good for generating
13:26heat.
13:27Brands try to reduce friction with
13:29something called a stearate coating.
13:31It's a microscopic dry lubricant baked
13:33over the rocks to keep them cool and
13:35stop the wood fibers from gumming up the
13:36paper. But, once that coating is gone
13:39and the rocks are dull, that friction
13:40generates pure heat.
13:42And that heat physically melts the
13:44wood's natural lignins, the organic glue
13:47that holds the wood fibers together.
13:49When you do this, you are burnishing the
13:50board. You are literally smashing the
13:52wood pores shut and sealing the surface.
13:57That expensive can of finish you bought
13:59is going to sit on top, beat up, or peel
14:02right off because it has absolutely
14:03nothing to grab onto.
14:05You wasted all that extra time sanding
14:07with a dead disc just to have to turn
14:09around and sand some more.
14:14We've only talked about hardwood so far,
14:16but
14:17what about softwood? I ran that exact
14:19same 15-minute test on pine as I did on
14:21hickory. Ceramics need resistance to
14:24stay sharp. So, that begs the question.
14:27Is pine just too soft to break it?
14:30Looking at the discs up close, your
14:31guess is as good as mine. But, the data
14:33shows us what our eyes can't see. All
14:36the ceramics just destroyed the pine.
14:38There's a physical reason for this
14:39aggressive bite. And it has everything
14:42to do with open versus closed coat.
14:45Closed coat means the abrasive rocks
14:46cover almost the entire surface of the
14:48disc. Think of it like a bed of nails.
14:50It all comes down to surface area and
14:52pressure. Because the rocks on a closed
14:54coat disc are packed tightly together,
14:56it drastically increases its surface
14:57area. And more surface area means you
14:59need more force to pop the balloon.
15:04For a sander, that means the downward
15:06force is distributed evenly across the
15:08entire pad, making sure no single rock
15:10has enough force to dig too deep. There
15:12are three specific times you'll likely
15:14want to reach for a closed coat, sanding
15:16between coats of film finish, polishing
15:18fully cured epoxy, or shaping a metal
15:20tool.
15:21Those all produce a fine dry powder. And
15:24that is critical because a closed coat
15:26disc has almost zero swarf clearance.
15:28>> That's swarf.
15:29>> No. Swarf clearance just means there is
15:31no empty space on the disc for dust to
15:33escape.
15:34Using it on a softwood like pine is a
15:36waste of time.
15:37Which is exactly why standard
15:39woodworking discs are open coat. Instead
15:41of a solid bed of nails, an open coat
15:43leaves out 30% of the rocks.
15:46That empty space helps clear out the
15:48sticky dust you get from soft woods like
15:50pine. When you remove those rocks, you
15:52aren't changing the downward force of
15:54your sander. You're just funneling all
15:56of it into way fewer rocks, which makes
15:58the paper naturally cut more
16:00aggressively.
16:04>> [snorts]
16:08>> Now, take that naturally aggressive open
16:10coat design and add ceramic rocks.
16:13Suddenly, it makes perfect sense why it
16:15violently tore through the pine.
16:17But, that doesn't mean it's the right
16:18move.
16:19Once you start that motor, you will
16:21quickly realize that on soft woods,
16:23primers, or veneers, you're more likely
16:25sanding through your material than
16:27sanding it.
16:29Using a less aggressive aluminum oxide
16:31on the pine, I actually had control. It
16:33only removed about 30 g compared to
16:35ceramic's massive 85 g. But, if you look
16:38closely at the ceramic, you can see the
16:40pine gumming up the disc. On a
16:42spreadsheet, these numbers make aluminum
16:43oxide look like a joke. But, unless
16:45you're trying to turn a 2x6 into a 1x6,
16:49making speed your only focus is exactly
16:51what sends you to finishing jail.
16:54If you care about your finish, you need
16:56to care about control.
16:57>> Heading for that small moon.
16:58>> Functionally, mesh is the ultimate
17:00extreme version of an open coat.
17:02>> That's no moon.
17:06>> There are some issues with mesh that you
17:08need to know about. First, the good.
17:11Brands like Festool use proprietary hole
17:13patterns to get you in their ecosystem.
17:16If the holes don't line up, your dust
17:18collection fails, but mesh don't care.
17:20>> [snorts]
17:21>> Mesh is a universal donor.
17:23That brings us to its dark side,
17:25the open net design. The back of a mesh
17:27disc treats your sander's Velcro pad
17:29like a cheese grater.
17:31Because there is no true backing, the
17:33mesh shifts as the sander moves. To make
17:35a bad situation worse, the plastic hooks
17:37on your sander poke directly through the
17:39mesh and grind against the wood.
17:42And that friction melts your sander's
17:43pad completely smooth.
17:47But thankfully, the fix is easy.
17:49You need a pad saver. It acts as a
17:51sacrificial layer to protect your hooks.
17:53Credit where credit is due, Gator. Yes,
17:56that Gator. And Diablo actually includes
17:59a pad saver in the box. 3M and others
18:01don't. At first, I thought that was
18:03incredibly cheap of them, but then I
18:05realized the why. To get maximum dust
18:07collection, you'll want your pad saver
18:09to match the hole pattern of your
18:11specific sander.
18:12If you slap on a universal pad saver,
18:14you might be choking your airflow.
18:17But because pros buy these by the
18:18hundreds, they don't want that upcharge.
18:20But for the weekend warrior market, a
18:22universal one is better than nothing.
18:25Durability is the main issue people have
18:27with mesh.
18:29It is fantastic on large flat surfaces,
18:31but the moment the disc catches a sharp
18:32splinter or a corner, it starts to
18:34unravel.
18:37Once that edge frays, it turns into a
18:3910,000 RPM weed whacker.
18:45If shredded mesh isn't your thing, then
18:47you have the hole punch options.
18:49But this will change your workflow. With
18:51mesh, you align a pad saver once, and
18:54then you can blindly swap out discs all
18:56day.
18:57With standard discs, you have to play
18:59match the holes every single time you
19:00change a disc.
19:02Paper is your baseline. It is the
19:04absolute staple of the DIY market, which
19:07is exactly why it fills the aisles at
19:08every hardware store. But beware the
19:10bargain bin discs. If you want to know
19:12if a paper disc is questionable, just
19:14fold it in half. A higher quality paper
19:16disc will actually take the bend. But,
19:18on a cheap disc, you'll hear that
19:20brittle glue crack and then just give
19:22up. And if the glue is this cheap, even
19:24without our test, you'll know that
19:25everything else is probably low quality,
19:27too. Paper's biggest advantage is that
19:29normally it costs less than other
19:31backings.
19:32If your sander hits an inside corner or
19:34you accidentally run it across a sharp
19:36edge,
19:37the paper will get damaged, but a cheap
19:39disc will start falling apart.
19:41The upside,
19:43it won't explode into a weed whacker
19:45like mesh does. Plus, with how little it
19:47can cost, you won't feel as guilty
19:49throwing it in the trash.
19:52Then there is film. Both the 3M 775 and
19:55the Duragold Purple use a polyester film
19:57backing.
19:59Essentially, it's a high-strength
20:00plastic sheet. It usually costs more and
20:03you typically have to order it online.
20:05But, that plastic backing makes it
20:07incredibly tough to tear,
20:09even on a sharp edge.
20:11And because the plastic is perfectly
20:13flat, it leaves a slightly more uniform
20:15finish.
20:16Now that we know the science and the
20:18traps, it's time for that final round.
20:23My cost per disc numbers are strictly
20:25based on the sticker price at the time I
20:26bought the discs. It doesn't include the
20:28price of gas, an Amazon Prime
20:30membership, or any hidden shipping
20:32taxes. For example, my Surf Prep order
20:35shipped from different facilities,
20:36meaning I got hit with separate shipping
20:38charges for each box. So, we didn't
20:40count those variables when calculating
20:42the cost per gram removed.
20:44As we've seen, the 3M 710 and 310 are
20:47hard to beat because of both the price
20:49per disc and the cost per gram removal.
20:51But, it's not all sunshine and rainbows.
20:53Because they are so popular, they
20:55constantly go out of stock.
20:57You think you're getting this, but then
20:59Amazon sends you this.
21:01Double-check before you buy. In those
21:04times, both the Duragold Purple options
21:06are not a bad backup. Diablo purple film
21:08cost 36 cents a disc, removed 54.6 grams
21:12with an average per gram cost removal of
21:14only 5 cents, right in line with 3M.
21:17There is only one catch, it uses a
21:19standard eight-hole pattern.
21:21If you don't have time to wait on a
21:22delivery, just run down to Home Depot
21:24and grab a box of Diablo Sandnet. It's a
21:27solid off-the-shelf option.
21:29I know this was a ton of data, so I put
21:31together a free sandpaper cheat sheet
21:33for your shop.
21:35Scan the QR code or hit the link in the
21:37description to access the shared drive.
21:39You'll find the cheat sheet, my raw data
21:41spreadsheet, and every graph I made for
21:42this video.
21:44All the discs that I recommend are
21:45linked in the description. Click here if
21:47you want to watch the 25 hours it took
21:49me to complete the sanding test. Or
21:51click here for a video YouTube thinks
21:52you'll actually watch.
21:54I'm Joseph with 5D Studio. I hope to see
21:56you next time. Won't be the same without
21:57you.

About this transcript

This page contains the full transcript of The Weird Physics of Sandpaper (Why You’re Working Too Hard) by Five Duck Studio, generated from the public captions YouTube serves with the video. The transcript has 3,856 words across 613 segments, with the original timestamps preserved so you can click any line to jump to that moment in the embedded player.

What you can do with it

Use the transcript to take notes, quote the speaker, build a study guide, generate a summary with ChatGPT or Claude via the YouTube Summary tool, or export it as a timed subtitle file with YouTube to SRT. You can also re-open it in the transcriber to translate the transcript into 100+ languages.

Free YouTube transcript tool

YouTube2Text is a free YouTube transcript generator — no signup, no daily limit. Paste any YouTube link and get the full transcript instantly, with timestamps, click-to-jump, translation to 100+ languages, AI prompts for ChatGPT, Claude, and Gemini, and exports to TXT, SRT, VTT, or Markdown.