Prevent leaching of Cyanoacrylate adhesive into the beer

[Kunal Vanjare]

Hello guys, a friend has asked me to brew an SOS batch for his birthday next month. I don't brew that often and have just the one fermenter which I am going to be using for my Hefeweizen batch this week.

What I do have is a 5 Ltr PET jar which I would like to use to ferment the batch for my friend. I was thinking I will cut a hole in the lid and use some of my silicone tubing as a blow-off hose instead of putting a stopper and airlock. To attach the hose to the lid, I would have used some cyanoacrylate based adhesive.

Now I am no pro but I do understand the risks of using these things. So was wondering if there is any way I can 'cure' the adhesive before using it for brewing?

Any help would be great. Thanks.

P.S- I do not live in the US. Buying another fermenter in such short notice is not possible

 

[IslandLizard]

If you drill the hole a tad (1 mm?) smaller than the outside diameter of the tubing, you don't need to glue anything. It holds in place by friction, due to a very tight fit.
I'd rather use vinyl tubing for a blow off than silicone, as it is less O2 permeable.

When drilling thin, hard plastic (the lid) it's easy to crack once the drill bit is almost through and starts to bite. So be gentle, and careful. Or try on a piece of scrap first. Maybe use some backing wood. Or drill a smaller hole and file or sand it out to the exact width, using a dowel or something tapered.

 

[Homebrew Harry]

I would do as IslandLizard says. That way you can change it out if you ever need to.

 

[Kunal Vanjare]

If you drill the hole a tad (1 mm?) smaller than the outside diameter of the tubing, you don't need to glue anything. It holds in place by friction, due to a very tight fit.
I'd rather use vinyl tubing for a blow off than silicone, as it is less O2 permeable.

When drilling thin, hard plastic (the lid) it's easy to crack once the drill bit is almost through and starts to bite. So be gentle, and careful. Or try on a piece of scrap first. Maybe use some backing wood. Or drill a smaller hole and file or sand it out to the exact width, using a dowel or something tapered.

Since I don't really have any power-tools handy, I was planning to use a screwdriver after heating the tip on a stove. That won't make a perfectly round hole, but I guess that should work right?

I will cut the hole 1mm smaller than the OD of the tube and use a file. Might have to clean the lid to remove any gunk from the filing or the actual cutting as well right?

Also, I do not have Vinyl tubing so I will have to use Silicone ones unfortunately. Is there a risk of oxidation?

 

[IslandLizard]

First, do you really need a blow off tube?

Instead, you could screw the lid on, but not tighten it all the way, leave a bit loosely, so fermentation CO2 can escape. You can loosely wrap some plastic film over the lid and top of the jar to prevent "things" from crawling up there.

Leave at least a liter of headspace (1/5-1/4 of your total jar's volume) above the wort/beer, and control your ferm temps as well as you can toward the lower end of the yeast's range, so fermentation won't be explosive. You'll make better beer that way too, while you shouldn't lose any beer that way either to blow-off. After a few days things will have settled down a bit anyway.

 

[Kunal Vanjare]

First, do you really need a blow off tube?

Instead, you could screw the lid on, but not tighten it all the way, leave a bit loosely, so fermentation CO2 can escape. You can loosely wrap some plastic film over the lid and top of the jar to prevent "things" from crawling up there.

Leave at least a liter of headspace (1/5-1/4 of your total jar's volume) above the wort/beer, and control your ferm temps as well as you can toward the lower end of the yeast's range, so fermentation won't be explosive. You'll make better beer that way too, while you shouldn't lose any beer that way either to blow-off. After a few days things will have settled down a bit anyway.

Don't need a blow-off tube but figured I'll use one just in case the fermentation goes crazy. I have brewed using a balloon airlock in the past that worked just fine.

I could use a sanitized AL foil with a pinhole or your trick of a slightly loose lid, but I am worried about the blow-off. Lower range of my yeast (Munich Classic) is around 17C(63F) right? Weather is kinda hot around here so the ferm temp might fluctuate a bit.

 

[IslandLizard]

You can go 2-3 degrees higher than 17C, but yeah, fermentation will become more vigorous. Place the fermenter in a cooler area that remains more constant in temp, and set it inside a tub with water, creating a (large) water jacket that regulates the temp better.

If you want the blowoff hose mounted in the lid, and you have a round file, make it as round as possible, and sand the last mm or 2 using a (round) dowel with a piece of sandpaper wrapped around it to widen the hole until the tubing fits snug. Silicone is very compressible it should not be a problem to get a tight and close fit.

If there happens to be a little gap, wrap a piece of sanitized plastic wrap and a rubber band or tie around the tubing where it meets the lid, to cover the gap, and to prevent it from sliding down too far.

I think keeping your ferm temps down is the bigger challenge...

 

[Beermeister32]

Go find yourself a stepped drill bit. This is what is used to drill holes in plastic. Once you get close to your blowoff tube size, you can check the tubing in the hole for a nice interference fit. No adhesive needed.