All language subtitles for S02E08 - Fiberglass Boats; Clothes Dryers; Bubble Gum; Fireworks (576p AMZN WEB-DL x265 Garshasp)_track4_[eng]

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Narrator:
Today on "How it's made"...

Fiberglass boats...

Clothes driers...

Bubble gum...

And fireworks.

They're sleek, they're fast,
And they're fun.

Fiberglass boats can jump waves
And turn on a dime.

The fiberglass body
Is low-maintenance and durable,

So these watercraft
Don't deteriorate

The way wooden boats can.

A computerized saw cuts out
The wood pieces

They'll use to build the mold
For the fiberglass boat.

It takes a team of artisans
About 15 months

To design and build the mold.

They first construct the frame.

Then they construct the shape
Out of fiberglass.

The mold must be perfect

In order to cast a boat that's
Free of faults and defects,

So they painstakingly work on
The mold's finish in particular,

Coating it in a special
High-resistance paint

That will withstand
About eight years of castings.

Once they finish the mold,

They can begin casting
The fiberglass boat.

The equipment feeds
Just the right ratio

Of fiberglass to plastic resin.

Fiberglass is glass in the form
Of very fine, flexible fibers.

They may look fragile,

But those fibers are stronger
Than steel,

And they won't burn, stretch,
Or rot,

So they make perfect
Boat-building material.

Workers make sure
They roll the fiberglass

Into every nook and cranny.

This is critical

Because if they don't apply
The fiberglass thoroughly,

The boat will have
Structural defects.

As heat within the fiberglass
Builds up, it hardens.

Next, they roll on
A material called roving.

It reinforces the fiberglass
And makes it more rigid.

They also install wood

In the areas where they'll
Later mount equipment.

They coat the wood
With fiberglass

To protect it from moisture.

After about an hour,

It's time to extract the casting
From the mold.

They use a lever system
To lift out the hull.

They cut out holes
For the mechanics.

Then they install
The boat's deck.

They install the motor
And the electrical wiring

For the mechanics and plumbing.

The boat truly takes shape
In the final assembly.

They put together the upper part
Of the boat, called the shell,

And the inside,
Called the liner.

They install the furniture...

Certain components
Are installed by hand,

Such as the dashboard.

Last stop, quality control --

A series of tests to ensure that
All the mechanics function well

And that the boat
Is absolutely watertight.

Finally, a wrapping is added

To protect the boat
During shipping.

Narrator: electric cars
Are cheaper to run

Than gasoline-powered cars.

Just plug them in to recharge.
No fill-up required.

But they cost 40% more to buy,
Which offsets the savings.

Battery technology will have to
Improve and come down in price

Before electric cars
Can truly take off.

Clothes dryers were invented
In europe in the early 1800s.

The lady of the house
Would put the clothes

In a metal barrel
With holes in it,

Then turn it by hand
Over the fire.

The first electric dryers
Were invented around 1915.

Most of the parts
Are made from steel

Just 3/100 of an inch thick.

The factory receives it from
The supplier in giant rolls.

They go onto a machine that cuts
Sheets about 3 feet long.

Using those sheets,

Industrial presses stamp out
Various dryer parts.

These are motor supports.

And this is the back panel
Of the drum,

The rotating compartment
That holds the clothes.

Note those small holes.
We'll come back to them shortly.

To form the side of the drum,

The machine bends a sheet
Of prepainted steel

Into a circular shape.

When a clothes dryer operates,

It sucks in outside air
Through a hole at the front.

The air passes through
The heating element

And goes into the drum,

Entering through those little
Holes you saw a few moments ago

Located in the back panel.

Once the automated machines
Have finished shaping the drum,

They form a groove
On its outside surface.

This groove is for the motorized
Belt that drives the drum.

Next, they put the drum
On another machine

That screws three baffles
In place.

Baffles are those thick plastic
Wings located inside the drum.

They're what throw the clothes
Around as it rotates.

Back on the automated line,
The drum's front rim goes on.

They manually assemble
The drum's back panel.

Then a machine installs it.

Next comes the exhaust duct.

Hot, moist air exits the drum
Through a series of holes

And a large slot
In the dryer door.

The air gets channeled downward
Through the lint screen,

Then goes through a duct at the
Front of the dryer to the fan.

The fan blows the air
Out this exhaust duct

At the back of the dryer.

The dryer's heating element

Works much like the element
In a toaster,

Except it consumes
A lot more power --

Up to 6,000 watts.

The factory receives the steel

And ceramic heating coils
Ready-made.

Workers simply position them
On a sheet of galvanized steel.

They also install a temperature
Sensor that shuts off power

Should something go wrong
And cause the dryer to overheat.

In the finishing department,

They coat the dryer
With powdered paint

That's heat-
And shock-resistant.

Then they assemble the bottom
And back of the appliance.

They install the motor

That drives both the belt
And the fan.

Then the exhaust duct goes in.

Automated machines prepare
The electrical wiring.

They paint and cut the wires...

...Then install a terminal
On each end.

Workers wire the dryers...

Then install the drum.

They close up the sides...

...Screw on the door,
Then wire up the control panel.

It's connected to a series
Of gears and switches

That control the dryer cycles.

The model
And serial-number sticker

Marks the last stop
On the assembly line.

Narrator: chewing gum dates back
To the ancient greeks,

Who chewed resin from trees.

Modern chewing gum was patented
In the u.S. In 1869

By -- believe it or not --
A dentist.

In 1928, another american
Invented bubble gum.

Bubble gum comes in gumballs
Of all colors and sizes,

But for blowing bubbles,

Nothing beats the chewy, gooey
Pink stuff in the twist wrap.

It all starts with a gum base,
The stuff that makes gum chewy.

Traditionally, the base came
From tree resin.

Today it's synthetic --
Made of plastics and rubbers.

They pour the gum base
Into a mixer,

Then add color and flavoring.

As it begins mixing, they pour
In glucose syrup, a sweetener.

Because it's liquid,
It helps keep the gum base soft.

Next, they add dextrose,
A powdered sweetener.

They blend the ingredients
For about 20 minutes.

The stirring action
Builds up heat,

Which melts everything together.

The mixture is ready

When it reaches the consistency
Of bread dough.

They transfer it by cart to a
Machine called the pre-extruder.

The machine squeezes the mixture
Through a narrow opening,

Like squeezing toothpaste
From the tube.

This transforms the big, bulky
Wad into thin, manageable strips

That can then go
Through the extruders.

The extruders squeeze each strip

Down to the actual width
Of a piece of bubble gum.

It comes out as one long,
Continuous stream,

To be cut into bite-size pieces
Later on.

This extrusion process heats up
The gum.

If they were to cut
And wrap it now,

It would stick to the wrapper,

So the next stop
Is a cooling chamber.

The gum goes in for 15 minutes

At temperatures between
37 and 45 degrees fahrenheit.

When the bubble gum comes out,

It's cooled down enough for what
They call the "Cut and wrap."

One machine does both jobs

In a fraction of a second.

Watch the action in slow motion.

As the continuous stream of gum
Enters on one end,

The machine cuts it
Into bite-size pieces,

Pushes each piece
Into a wax-paper wrapper,

Then twists both ends
Of the wrapper closed.

Here's the slow-motion replay
From a different angle.

The machine processes 900 pieces
Of bubble gum per minute.

Last stop -- packaging.

The bubble gum
Moves onto a scale

That automatically weighs out
The right amount per tub.

They seal the tub with plastic
To make it airtight.

This keeps the bubble gum fresh.

Ever wonder why bubble gum
Is pink?

It's because that's the only
Color walter diemer had on hand

When he invented this treat
Back in 1928.

Since then,
The color just stuck.

Narrator: what's a 4th of july
Celebration without fireworks --

Brilliant colors exploding
In the air,

The oohs and ahhs they elicit
On the ground?

Fireworks are so high-tech
These days,

It's easy to forget
They're not a modern invention.

Historians believe gunpowder,

The explosive ingredient
In fireworks,

Was invented in china
Around 1000 a.D.

It's said
That in a famous battle,

The chinese emperor illuminated
The sky with it,

Scaring away the enemy.

During the renaissance,

The europeans invented the type
Of fireworks we know today.

Modern pyrotechnicians

Use computers to ignite
Fireworks from a safe distance

And to synchronize their bursts
With music.

Assembling explosives
Into fireworks

Is the job
Of the pyrotechnician.

Even the tiniest spark of static
Electricity could set them off,

So antistatic gloves are a must.

A firework is made up

Of separate compartments
Within a shell.

The burning fuse explodes
One compartment at a time,

Creating those staggered bursts
In the sky.

The pyrotechnician first glues
The main fuse

Into the bottom of the shell.

The glue is naturally colorless.

It's dyed blue so he can tell
Exactly where he's applying it.

He puts the bottom aside to work
On the second compartment

Of this 2-compartment firework.

He starts by spooning a powdered
Explosive into the center.

Then he caps it.

Here he's working
On two fireworks at a time.

Next step -- a brown cardboard
Shock absorber

To shield this compartment from
The first compartment explosion.

Then a corrugated cardboard disk
And a plastic spacer.

It'll take the fuse
1 1/2 seconds

To burn through
These two components,

Creating a slight delay

Between the first explosion
And the second.

Gluing the second compartment
Together is tricky.

If it's too tight,
It'll stifle the explosion,

But it has to be tight enough
To withstand the delay.

With the second compartment
Done,

It's time to prepare the first.

He glues a sleeve onto a case,

Then fills it
With hundreds of stars.

Stars are what create
The flashes of color.

They're carefully measured
Explosives

Mixed with coloring agents

Such as magnesium for white,
Copper salts for blue,

And charcoal for orange.

The pyrotechnician
Must handle them gingerly,

Or they could detonate.

Next, he adds comets, another
Type of exploding decoration.

He tops it off with gunpowder.

Finally, he glues
The two compartments together,

Filling the remaining space

With the same combination
Of ingredients.

Once the shell is full,
He glues on the cover,

And the tighter, the better.

The more pressure
That builds up,

The bigger and more spectacular
The explosion.

Next, he wraps the fireworks
In craft paper.

The label uses
International color codes

To indicate the size
Of the shell.

The lift charge --

A gunpowder bag with a long,
Fast-action fuse --

Goes at the base of the shell.

That's what'll send the firework
Into the sky.

When they light the main fuse
At the top,

It simultaneously
Lights two secondary fuses --

The time-delay fuse
Inside the shell,

Running through the compartments
Of explosives

And that long fuse
Running along the outside

Down to the lift charge
At the base.

Once the lift charge ignites,

Heat and gas build up inside the
Launch tube until they explode,

Propelling the firework
Close to 1,000 feet skyward.

Let the light show begin.

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