I Built an Invisible Katana (it's indestructible)

have you ever seen an invisible

sword well I think I have a few days ago

I saw this picture right here that is an

invisible sword and now I want one just

like that a sword that's not all

invisible but also destructible and

sharp a sword that's basically like a

normal one but that you can't see I'm

going to build one not sure how yet I'm

going to have to figure it out and then

I'm going to test its sharpness and

durability against increasingly harder

targets the first step was choosing the

right material and the first one that

popped into my head well it was glass

glass is transparent when it's cleaner

than that and you can make it pretty

sharp by using a diamond Stone like it

did here but even though there are some

kinds of glass that can be more

resistant than usual and even

indestructible according to the

companies that sell them the problem

with glass is that glass is

glass and glass breaks at least way too

easily to make a katana out of it but

there is another material that not only

is transparent but it's 10 times more

impact resistant than steel by weight

I'm talking about polycarbonate it is

generally used for riot shields armored

vehicles safety glasses and other

indestructible items and because of all

that it sounds like the perfect material

for the job but I kind of still want to

see for myself how hard it actually is

to find that out I'm carrying out a

small sample from the panel I'm planning

to use for the katana and the idea is to

hit hit the polycarbonate as hard as I

can with this unnecessarily big

Sledgehammer 3 2

[Applause]

1 and well I'm not exactly sure what

just happened I only know that even

though B saw horses broke because of the

impact the polycarbonate panel is

completely fine this thing has one

scratch but you can't even feel it it's

not even bended or anything it's like

insane and since polycarb is clearly

resilient meaning it can bend like a lot

without breaking it's definitely my best

option so to make the katana I got a big

panel of polycarbonate 2 m by 0.5 and 12

mm or 0.47 in Stick which is also the

maximum thickness I could find for this

material and this is going to be the

invisible and indestructible body of the

sword now to cut the right shape out of

the panel I'm going to use tape what I

mean is that tape should make it easier

to draw the consistent curve of the

katana on the panel and then I can use

that as a reference for the actual cut

and after outlining the tip the edge and

completing the handle I can start to see

the final shape of the sword there is

just one thing to point out I

involuntarily made this thing big like

way too big it's basically twice as

large as a normal Katana and I'm not

sure if I should be excited because the

katana is massive and it's going to be

powerful or worried because the katana

is massive and I might not be able to

even lifted but after making a few

scientific tests I realized that because

polycarbonate is so much lighter than

steel it shouldn't be a problem to swing

the sword even if it's that big and so

I'm not worried anymore I'm just really

excited instead then I use the jigsaw to

C out a smaller perimeter around the

sword so that it's going to be easier to

work with it in the next step and after

doing that it became even more

noticeable how big this thing is going

to be now the next step is to crop the

actual shape of the sword out of the

panel and and to do that I'm going to

use a b saw then after cutting the shape

I can remove the protective film and I'm

going to be able to see if the sword

actually looks invisible the problem is

that Ben sace don't look too friendly

and most importantly I don't exactly

know how to use one so I got pretty

nervous

uh I already cut one part I forgot to

film I cut it really bad you see the

good thing is that I need to follow the

in interor line this part inside here so

my terrible cut wasn't actually a big

deal for now then I cut the extra

material out of the other side of the

katana and like that I was getting

closer now comes the hardest part I need

to follow these lines here and be

precise now this is definitely scarier

and I don't mind my fingers being close

to a deadly saw but making a mistake

here means removing material out of the

final Katana and potentially having to

start from zero luckily though I was

getting the hang of it and after

removing the extra material from the

handle I'm fixing the final details on

the Belt grinder as you can clearly see

here anyways like that the first step to

make the sword is complete I'm also

happy to see the weight of the katana is

not a problem at all it's not too light

not too heavy and the katana is not

bending on itself which means I'm

definitely on the right track and now a

few seconds of Silence while I remove

the plastic wrap

now the sword looks pretty invisible

already but inside the shop the effect

is actually weaker because of the lights

like in real life like like this it's

completely transparent for me

wait what if I do

this and that was already more like it

or less like it but outside it gets even

better bear in mind you can still see

the edges because there is no blade and

the spine is not polished so it might be

that the katana also looks darker

because the edges block the light but

when the edges are perfectly

perpendicular to the camera this thing

looks fake the effect is even stronger

when there is light behind it and I'm

very excited to see what this Katana is

going to look look like when it's

done I'm going to get this thing sharp

then I'm going to make the handle and

then I'm going to test it

against a lot of

stuff the first step to get the sword

sharp is to create a bevel on the blade

so after marking the center of the blade

using a caliper I'm retracing the line

with a pencil this line is going to be

my reference for the edge while grinding

also to make sure I'm going to grind the

blade symmetrically on both sides

basically like this I made this tool

this mechanism allows me to set a

certain angle so that when I grind the

sword with a belt grinder the angle

should stay consistent as well as the

bevel on both sides and this is all

Theory by the way I've never grinded

almost anything in my life and this

could honestly mess up the entire sword

but of course there is only one way to

find

out and well even though I felt like I

was doing everything wrong at the

beginning after basically 1 hour of

grinding the first side of the bevel was

completed and besides making an absolute

mess everywhere including on my face I

think it came out bad but much better

than expected and so after repeating the

process on the other side of the blade

the rush shape of the sword is done the

katana is not sharp yet but it has an

edge now and so the next step is going

to be making it invisible through do

that I'm going to smooth out the angle

between the spine and the bevel mainly

to prevent Reflections like the ones you

see here and while doing so I'm going to

also remove the scratches I got from the

belt grinder and hopefully turn turned

the katana even more transparent than

how it was before so I got a sander with

eight different bads from a course crit

to basically a polishing one and by

sending the katana with each one of the

pads in theory I'm going to be able to

make it transparent and well after a

little more than 2 hours I was basically

done with a first pad anyways I made

sure to remove every single scratch from

the belt grinder and even after just the

corser pad the katana already looks

pretty cool now I'm going to repeat the

process seven times and so I did each

time with a finer grd and each time

making sure to remove all the scratches

that were there before and after about 1

hour and something I was using the final

pad after that I'm sending everything

with a 2500 great sandpaper by hand and

with this I'm finally starting to see

the first good results now it's looking

good when it's wet it looks great

right now there are still a lot of micro

scratches on the surface of the blade

and that's why the katana doesn't really

look transparent yet so now I'm going to

try to remove them using this headlight

polisher and after applying it on the

sword with a sponged pad the katana was

polished and transparent there is just

one problem that I'm realizing literally

right now I forgot about

physics yeah want to know what happens

when a block of transparent material has

variable thickness like in my case

Distortion that's what happens and so

even though the katana looks good and

it's transparent when you look through

it it's going to always distort the

objects behind it basically like you see

here and even though I actually like

this Katana and I spent three days

working on it I already wrote the title

of this video and I don't want to

clickbait you so the sword has to be

more invisible than that now the problem

is that I would always need a bevel to

make the sword sharp and a bevel creates

Distortion but what if what if I try to

keep the thickness consistent as long as

I can and then make a really short

bevel by doing that in theory the entire

sword will be invisible and only a small

part of it would create distortions so

to confirm the theory I tried making a

small sample with this new concept and

it turned out honestly great let's make

another

sword so I drew a new sword cut it out

of the panel with the band saw flat in

the edges and like that had the new Rush

shape of the katana then I made a new

shorter bevel on the Belt grinder and

even though this took a while like a

long long while the new Edge came out so

much better than the old one so after

polishing it and polishing the spine of

the blade and turning my hand into a

tomato after one one day of work the

final blade is ready you can obviously

still see the bevel and the bevel still

distorts what's behind it but besides

that now the entire blade is completely

transparent for comparison this is how

version one of the katana looked and

this is how it looks now I really like

this and the more I look at this thing

the more I can't wait to test it the

katana is also pretty sharp now and I

know that because I randomly hit the

damm's head with the blade and this

happened so yeah it cuts at this point

to complete the katana I got to make the

handle and the guard Katana guards are

pieces of art they're often handmade and

they just look awesome but I'm a

minimalist so mine is just transparent I

actually tried to do something fancier

but I ended up right away with a chubby

Pac-Man and then it took me one day to

make this hole but at least it fits

nicely on the katana and at this point I

only got the handle left so my initial

plan was to use the acrylic block and

then carve a handle of it but besides

that taking a lot of time I fear it will

probably not come out as transparent as

I wanted because following the plan I

need to make a hole into the block and

then fit the handle into it and the

problem with hose is that they are

really hard to polish moreover I only

need to add just a few extra centimeters

on the thickness of the handle so why

can't I just glue extra polycarbonate to

it and then shape everything as a handle

well I tried on a smaller sample first

using super glue and it honestly worked

perfectly it's actually really strong I

hit it here and it didn't move so I cut

two pieces of polycarbonate with the

same dimensions of the handle and after

placing an entire super glue bottle on

each side of the handle I glued the two

pieces to it now I need to smooth the

edges and also reduce the thickness of

the Block in order to get the shape of

the final handle and I'm seeing this

just because there is no way for you to

tell but I got a big smile under the

mask there mainly because after grinding

for 30 minutes I was really happy about

how the handle was turning

out swear it's not dangerous besides

that the tape I put on the guard to

protect it didn't protect the guard at

all but it created a sort of pattern

that somehow reminds me of anime stuff

so I think I'm going to keep it this way

and since the handle already feels

pretty good in my hands I simply

finished it by polishing it as I

previously did with the body of the

sword and even though it was completely

random the glue created a unique effect

on the handle kind of looks like ice

anyways with this the katana is finally

completed and honestly I don't think it

looks cool I think it just looks like

I'm about to start my own anime Revenge

arc when I'm holding this thing I

absolutely love it of course you can

still C The Edge but everything else is

basically transparent especially when

there is ground or objects behind it and

now I want to test it though I want to

find out if this actually works like a

sword I want to see how well it can cut

and how powerful it is to find it out I

got a bunch of targets from soft to hard

pineapple watermelon and pumpkin a

wooden plank a ballistic dummy and then

a brick the plan is to try to cut all

this and see what happens to the sword

pineapple is first hardness one out of

10 a normal sword would easily cut this

but I'm not even sure if my Katana can

actually

cut let's find out well it didn't took

me much to realize three two

one that a really does

cut

hi and well I'm really happy about that

what I didn't know is that my happiness

wasn't going to last long though because

on the next attempt the second worst

thing that could possibly happen

happened no I wasn't expecting this at

all like at

all the sword snapped right after the

handle and then I stood literally 5

minutes like this trying to figure out

what why how was this possible

polycarbonate is basically unbreakable

then why did this happen the blade

itself is absolutely fine though it

doesn't even have a

scratch and then it clicked the reason

why polycarbonate is so resistant is

because it can bend a lot and absorb the

impacts and my theory is that by Glu in

extra material on the handle I just made

it way more rigid than the blade

effectively removing its ability to

bend so who says I need the handle if my

theory is right the sword without the

handle would be basically impossible to

break I'm going to use it this way and

if it works and if it's strong then I'm

going to remove the sharpness here but

if it works I mean it's perfect so

watermelon is next hardness 3 out of 10

I'm temporarily using a clo as a handle

to not cut myself and even though I'm a

little worried there's only one way to

find out what this sword can actually do

one and luckily it went through the

watermelon without

problems it doesn't cut clean probably

because of the thickness of the blade

and the fact that the blade bends a lot

but so far it cuts but I'm going to eat

this one next pumpkin hardness 5 out of

10 and this is not a normal pumpkin

besides the

shape but even my super sonic chain whip

struggled to slice one of this it's like

it's way harder than it looks and yet

the katana actually sliced this one and

also pretty

easily the cut is also fairly clean this

time and once again the blade is

completely fine now I'm getting to the

hard targets St the next one is a wooden

plank and it's pretty thick too so I

think there are three possible ways this

can go down the katana could snap and

break in half it could Bend pretty badly

and stay bended or but it's unlikely it

will break the wood to find out I set up

the wooden plank and I fix the bottom

and the top so that it doesn't move when

I hit it the problem is that I still

haven't figure out how strong this blade

actually is and at this point I really

have no idea what's going to happen all

right let's just do it

3 2

1 and well I wasn't expecting

that it doesn't even

have nothing I completely destroyed that

and dented that one and the edge of the

blade is absolutely perfect so I think I

definitely underestimated this thing let

me let me try again I'm going to try to

break that piece I thought it was maybe

just a fluke so I hit the plank again

and the same thing happened this is the

mark he

left the wood is broken and the blade is

not even dented at this point I only got

the two hardest targets left so I

quickly went back to the shop and it's m

in the edges of the handle and now I got

something like this and I wasn't

expecting it but this handle works just

as well as the old one and so I can move

on with the next test this is a

ballistic dummy it has a layer of

ballistic gelatin which should simulate

muscle tissue and it also simulate bones

I'm going to hear it twice once here on

the neck where there is a lot of gelatin

and then once on the

Skool I think it's going to break hit

one

neck

I'm checking the blade right away to see

if it's shipped or it cracked but it's

perfect all right also the dummy looks

fine though it didn't seem like the

blade went through at first oh yeah I

caught it oh no way and then I saw it I

don't know if you can see but I got it

right here and it turns out the katana

not only sliced the gelatin and went

deep oh my God but it actually shattered

the bones below it that that is a piece

of bone it's insane because after the

handle I thought it was going to be an

absolute fail and instead the edge of

the katana was as sharp as when I

started testing it this thing is insane

I love it anyways now I'm going to go

for the head three two

one now a red thing is coming out of the

head of the ballistic dummy and I wasn't

expecting it

so I'm switching to zombie mode for the

next shots to make YouTube happy and

here you can kind of see the damage the

sko got cracked from here to here and

there is a deep gut where the katana hit

and the katana itself even after hitting

the bone doesn't even have a scratch on

it this thing is crazy the last Target

though is a break hardness 10 out of 10

this is clearly a dumb test I shouldn't

do this but so far the katana destroyed

everything without getting damaged so

where is the limit I want to find that I

already know the edge is probably going

to get damaged but I can always fix that

by resharpen it but I want to see if

it's going to crack or

break and I hope

not could have chosen a smaller brick to

be fair well I got the thickest one I

could find instead anyways after a bit

of mental preparation I loaded my swing

and I hit the Brak as hard as it

could

honestly this a win little

chips and damage on the brick now I want

also try to hit a smaller brick and see

what happens to the katana and the break

and this

time the katana actually broke the break

and I was definitely happy about it but

the best part for me is not not even the

broken break is the fact that after all

that this is the only damage on the

blade then I went back to the workshop

and after fixing it and polishing it the

blade itself has a few scratches but the

edge is basically brand new Next I'm

going to build an insanely powerful

slingshot subscribe to see when it will

come out and also let me know in the

comments what you want to see me build

after that one if you like my videos you

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