Tom Selleck and ‘Blue Bloods’ crew to celebrate after filming series finale

Tom Selleck and the cast of "Blue Bloods" have finished filming the final season. CBS

No longer their Finest hour

No advance picnicking, bathing or sunburning for Tom Selleck.

He and his crew quietly marked the finale of his 15 TV years playing NYC police commish Frank Reagan.

That glorious mustache wasn’t ready to be shaved. He wasn’t ready to stop filming. We loved it. He loved it. Audiences loved it. But CBS in its crankiness decided “Enough.”

So, pasta for them all. The whole group. Monday night at Elio’s.

Explosive backstory

Patrick Cyrana’s a pyrotechnic specialist. His New Jersey store is Backyard Heroes Fireworks.

“July Fourth testing starts in April. The stuff’s made mostly in China. Our agents there work constantly on our hundreds of thousands of containers. Each gets tested because moisture can create mishaps.

“Transport’s by ship. No airplane. All safe unless some fire happens onboard — which doesn’t happen. A ship crashing could cause an issue. On the road heavily regulated by the Department of Transportation. Ensured by Lloyd’s of London.

“Average July Fourth display costs about $20,000. Large park, big municipality is $50,000. Small town $5,000. Nothing comes down from our zero debris fireworks. Eyes are safe. Cardboard casings. The stuff is biodegradable.

“Of course, you can always have a low break, misfire or something where a shell breaks low or sets off in the rack. Then the wood, plastic, every component flies everywhere.

“Primarily, it’s black powder. Sulfur, charcoal, potassium nitrate form a powder that creates fire. Heavy metals create color. It’s black powder inside a cardboard tube or round ball. That aerial shell becomes a rocket.

“Ships, containers, US regulations make it too expensive to manufacture here. One container could hold $60,000 worth. Then, $30,000 to ship and that’s risen recently.”

Anything ever go wrong?

“Fires sometimes. Or hangs in the sky longer than it should. Or a shell rises only a short distance. We fire electronically. Set everything ahead of time, then press buttons.

“There’s no crankiness to it. Won’t pop off spontaneously. It needs an ignition. Forget a cigar or cigarette that has a flame.”

FYI: Before reaching his Jersey store, fireworks began in China, by 15th century widely used in Europe.

So everyone, have your July Fourth with its warm potato salad, friendly ants, crappy coffee and pesty relatives — and enjoy America’s holiday.

Feeling peckish

But alright already with celebrating out. The indoor problem is: Tip or don’t tip?

Plus, do we also schmear the maître d’ who in kindergarten learned to remove a bill from a hand before the teacher got it out of a money clip?

Plus: Dine outdoors in a bus lane so petroleum goes with chicken or indoors where the air conditioner’s broken?

Also, think it’s fair when they now suddenly, newly charge for bread? Or water? Those things are free even in prisons.

America’s so big who knows how Columbus almost could’ve missed it in the first place. He and his guys schlepped over in the Nina, the Pinta and the Santa Maria.

And today? Pick one. Most of us are still in a similar leaky boat.

And not only in New York, kids, not only in New York — but happy July Fourth everyone.