Best Way to Install Airlock Grommet in Bucket Lid

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Cogswell

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What's the best way to punch a hole for an airlock grommet in a plastic bucket lid?

This is what my grommets look like:
61wH5xZf4hS._AC_SL1500_.jpg


I measured the width in the middle area and it's about 12mm or almost 1/2 inch.

I know a regular 1/2" drill will leave a mess of a hole. I was thinking a punch like these from Harbor Freight would be good for the job:

image_18468.jpg

Is there a better way to get a nice clean 12mm hole in a bucket lid?
 

GrowleyMonster

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Sure, you can use a hole punch. But a spade bit works. The trick is to not let the corners of the bit cut completely through. Let them just make a groove, and then follow it with your knife. A forstner bit works. Probably the most common method is to use a step drill. Amazon.com: Neiko 10194A Titanium Step Drill Bit, High Speed Steel | 1/4" to 1-3/8" | Total 10 Step Sizes : Industrial & Scientific

When you have your hole, you can dress it up with a round file, or some sandpaper rolled up around a dowel or just your finger.
 

GrowleyMonster

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BTW, if you upgrade from the bucket to a Big Mouth Bubbler, you won't be sorry. Buckets can be a big PITA, though they are good for a first time brewer who wants to get in cheaply. I like the BMB better than a bucket because it can be difficult to open and close a bucket lid and still have a good seal every time. I like the BMB better than a carboy because the wide opening makes it easy to clean.
 

Henbrew

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If you use a drill, you can use a hot soldering iron to clean up the edges. I've had some luck with deburring tools but they can get stuck in softer plastic. Quick and dirty way would be to just use a lighter to smooth out the hole.
 

Wables

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I have some lids with grommets that work fine. I have some with 1" or so holes that take a carboy bung. The great thing about those is that you can pull them and take a quick gravity sample with a turkey baster with minimal O2 intrusion. That's old school 2005 technology right there.
 

FloppyKnockers

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I avoid Harbor Freight at all costs. Just drill a hole. There's minimal mess, it's fast, reliable, and easy.
 

grampamark

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Drill hole. Insert grommet. Once the grommet is in place no one will be able to see the hole. And, no matter how much overthinking goes into the process, the resulting bucket/lid combo won’t be airtight.

Simplest way to drill a clean hole in a thin workpiece is to place a backer (block of scrap wood works great) below the workpiece. Drill bit, of any style or source, will cut cleanly through the thinner material on its way into the backer.
 
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Cogswell

Cogswell

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The Harbor Freight punch works great. I just made ten fermentation lids in five minutes. I used a small piece of scrap 2x4 as a backer. One strike with a 5lb mini-sledge makes a perfect hole, nice and clean. The 1/2 inch punch is a good size for the black grommets. They slip in easy and tighten nicely with the insertion of a tapered airlock stem.

All my lids are soft HDPE...what Uline calls "EZ Peel" lids. Not sure about results with the standard hard lids.
 

MaxStout

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Any sharp drill bit will work. You can scrape off the plastic burrs with a sharp knife. If you want a better seal around the grommet, a dab of keg lube will do, but closing that leak is kind of pointless when you consider how leaky the lid is in comparison.

For buckets, close is good enough. Or step up to a plastic carboy or big mouth bubbler. Or, if you can spend the $$, a stainless fermenter like Brew Bucket, Delta Ferm Tank, Chapman, etc.
 

CascadesBrewer

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What's the best way to punch a hole for an airlock grommet in a plastic bucket lid?
While I have never tried it, I am curious if the best way would be to use a hole saw to drill a hole big enough for a 10# stopper instead of using a grommet. I have gotten used to dry hopping in my Fermonster by just pulling out the stopper, dropping in the hops (either pouring them directly or with a funnel), then quickly putting the stopper back in place. A bigger hole would give the ability to dry hop without taking off the lid, a better way to peak inside, and maybe even a way to take a gravity reading with a thief device.
 
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