[brewmonk]

I usually use the grolsch style bottles with the resealable tops, but did my first bottling with crowns.  Things seem sealed, but I worry about a weak seal.  Would it be obvious if there isn't a good enough seal? And is there any good way to check?

[tumarkin]

Are you using a bench capper or one of the hand-held wing cappers? I've never had a poor seal or leaking cap with my bench capper.

[Mark G]

You could put some tight fitting balloons over the top of a few bottles. If they start inflating, you have bad seals.

[brewmonk]

I used a hand-held wing capper.

[tygo]

I used a hand-held wing capper.

They can be a little inconsistent, especially if they've been used a bunch.  Take a look at the cap after you cap it and see if it looks consistent all the way around or if it seems a little skewed to one side or another.

[Joe Sr.]

I've never had an issue with a good seal in well over ten years using a hand-held capper.

As long as the caps are seated correctly, they should seal.

If it's not crimped properly, it should be visible.

[Hokerer]

Every time I stumble across this thread, a walrus at a Tupperware party keeps popping into my head 

[SpanishCastleAle]

I would think submerging them, upright, in water (warmer than the beer) would cause bubbles to leak from the cap if it was leaky.

[tubercle]

Hundreds and hundreds of bottles sealed with a wing capper.

Zero fails.

[morticaixavier]

Hundreds and hundreds of bottles sealed with a wing capper.

Zero fails.

here to. Also this last capper I got tends to crimp the caps slightly imperfectly and still no bad seals

[SpanishCastleAle]

I was cellarmaster at my club's last comp, almost 600 entries and I saw just about every one of them.  Some of them looked like they used spent caps that they flattened with a big hammer and used a crowbar to get the caps on, just gnarly. But they still sealed.

[Slowbrew]

Seems like a RDWHAHB type of question.   

I've used a hand held caper for 14 years and never had a problem.

Paul

[Jimmy K]

After a few thousand caps used, I'd say crown cap seals are pretty idiot proof.