turns all the water in your bathtub black.

But how big would the bomb need to be

to black out an entire swimming pool?

Let's try 2,000 pounds.

So to make our large molds, we're

going back to our old friend, fiberglass,

which we used to make the bowl from our marshmallows video.

We're going to make two halves that'll

come apart and hopefully reveal a giant bath bomb.

This epoxy just soaks into the fiberglass

and makes everything rock solid.

Ta-da!

Right behind me, there, is 31 50-pound bags of materials.

The recipe is one part cornstarch, one part citric

acid, to two parts baking soda.

And then we add the dye to turn it black.

That's your regular bath bomb.

We're making one a tad bit bigger.

Once we get this first batch done,

there's, like, seven or eight more to go.

So that's good.

Not bad for a day's work, right?

I'm putting this in the sun to bake.

I've got to dry this sucker out.

I'm so glad I started rolling.

Did you drop it in there?

I got this, guys.

We're done!

We've completed the bath bomb.

Now we wait till tomorrow and we try to figure out

how to get it out of the mold.

We're going to cut all of the shell off and all the support.

We're going to kind of tip the back end

and let the whole thing roll into the pool.

Ah.

That's one big bath bomb, y'all.

[SCREAMING]

That was crazy.

Look how green it looks.

Get your own black bath bomb and see hundreds of other gifts

we've discovered at Vat19.com.

Hey, if you guys want to see a little bit more

about how we put this whole thing together,

head on over to Vat19.com, where we have exclusive

behind the scenes footage.

Do you guys think this counts as my bath for the day?

Yeah, you're swimming, man.

Yeah.

Yeah.

Vat19.com.