Bodgineering - DIY carbonation

[Oldgreybeard]

As the CO2 cylinders (from BOC) have a maximum pressure of 50 Bar, I would imagine that the regulators have a different fitting to prevent anyone trying to use the regulators on any of the other higher pressure (up to 300 Bar) gasses.

That makes sense. I have a distant memory of there being thread differences between different gases, too. I had a small oxyacetylene welding set years ago and I'm sure that the threads were reversed so that the oxygen regulator couldn't be accidentally screwed on to the acetylene bottle.

I've decided to play around with getting finer CO2 bubbles into the water, so have ordered a stainless steel "carbonation stone". This should get more CO2 into the water at lower pressures, so may speed up the process a bit.

[Fintray]

As the CO2 cylinders (from BOC) have a maximum pressure of 50 Bar, I would imagine that the regulators have a different fitting to prevent anyone trying to use the regulators on any of the other higher pressure (up to 300 Bar) gasses.

That makes sense. I have a distant memory of there being thread differences between different gases, too. I had a small oxyacetylene welding set years ago and I'm sure that the threads were reversed so that the oxygen regulator couldn't be accidentally screwed on to the acetylene bottle.

That's correct the fuel gas threads are all L/H whilst oxygen is R/H.

[Swwils]

Make sure you buy food grade gas not gas for welding.

[Oldgreybeard]

Make sure you buy food grade gas not gas for welding.

This seems to be an interesting point, as I've spoken with our local gas distributor and the chap there has told me that there is no difference and that all their CO2 comes from the same source. They refill bottles on site and no matter what the bottle is going to be used for it gets filled with the same CO2. From what I've read the only difference between "food grade" and any other gas cylinder (like those used with aquariums, paintball guns, MIG welding, etc) is that the cylinders are cleaned internally after manufacture, so there's less likely to be manufacturing dust/particles left inside them.

At the moment I'm using a MIG welding gas cylinder, really because that was the cheapest way to knock up a rig to see how well it works. Lots of others into the DIY carbonation thing seem to also use these cylinders. They aren't that good in terms of value, but are still a lot cheaper than using Sodastream cylinders. The plan is to get a 6.35kg pub gas bottle for the permanent setup. They cost about £92 initially, then £36 per refill, which works out to about 4p/litre of carbonated water. Bit better than the 38p/litre for the Sodastream.

[nowty]

Sodastream nostalgia, I think this is from 1979, I still remember something weird happened the third time Tommy Cooper pressed the button.


Always wanted one, but never bothered because of the cost. I drink at least two litres of supermarket bottled fizzy water per day which is under 20p a litre but it does concern me about my plastic footprint.

There is a simple how to guide here, (method 3) which aligns to Oldgreybeard's method.
https://www.wikihow.com/Carbonate-a-Beverage

Its doing my head in as you have to shake it to get the CO2 in when normally when you shake a fizzy drink it comes out.

[AE-NMidlands]

Make sure you buy food grade gas not gas for welding.

This seems to be an interesting point, as I've spoken with our local gas distributor and the chap there has told me that there is no difference and that all their CO2 comes from the same source. They refill bottles on site and no matter what the bottle is going to be used for it gets filled with the same CO2. From what I've read the only difference between "food grade" and any other gas cylinder (like those used with aquariums, paintball guns, MIG welding, etc) is that the cylinders are cleaned internally after manufacture, so there's less likely to be manufacturing dust/particles left inside them.

At the moment I'm using a MIG welding gas cylinder, really because that was the cheapest way to knock up a rig to see how well it works. Lots of others into the DIY carbonation thing seem to also use these cylinders. They aren't that good in terms of value, but are still a lot cheaper than using Sodastream cylinders. The plan is to get a 6.35kg pub gas bottle for the permanent setup. They cost about £92 initially, then £36 per refill, which works out to about 4p/litre of carbonated water. Bit better than the 38p/litre for the Sodastream.

A very deep-thinking engineer friend asked me about this when I had access to some British Standards, as he was thinking of using his welding CO2 for carbonation too (probably just blanketing a beer keg actually.) I couldn't get hold of the right ones but later he told me that he had discovered that the difference between welding and food-grade gas was the permitted humidity. Welding gas had to be a lot drier apparently.
A

[Oldgreybeard]

The first time I tried this rig I charged a bottle of water to about 40psi, turned off the CO2, then shook the bottle and was amazed to see how much the pressure dropped as the CO2 was dissolved into the water. The pressure dropped right back to around 10psi with just a few seconds of shaking.

The idea behind trying a carbonation stone is to see if this removes the need to shake the bottle. I think it may, as in theory smaller bubbles of CO2 should make it dissolve more quickly, because of the much increased surface area of each bubble relative to its volume. The stainless carbonation stone I've ordered wasn't that expensive, about £8, and looks like this. It will fit on the end of the dip pipe that goes inside the bottle:

[nowty]

So shaking the bottle under high pressure gets the CO2 in the water and shaking already carbonated water at low pressure gets the CO2 out.

The paradox is fixed, my heads better now.

[SafetyThird]

A friend of mine has a set up similar to OGB's but using industrial connectors and regulators. He has an entire lab and workshop as his job is engineering biochemical processes and equipment so built something himself.

We use a Sodastream and I now have an adaptor to go from a standard CO2 bottle to the sodastream. Just need to get a co2 bottle now. If you have a BOC type of pub bottle, where to you get them filled? Do you have to have an account with BOC or can they be taken to, for example, a welding place and refilled or would I need to find a friendly landlord to exchange them for me?

I know someone who has several short BOC CO2 bottles for setting up temporary beer pumps for events and could get one from them but not sure how I'd get it refilled easily.

[Oldgreybeard]

A friend of mine has a set up similar to OGB's but using industrial connectors and regulators. He has an entire lab and workshop as his job is engineering biochemical processes and equipment so built something himself.

We use a Sodastream and I now have an adaptor to go from a standard CO2 bottle to the sodastream. Just need to get a co2 bottle now. If you have a BOC type of pub bottle, where to you get them filled? Do you have to have an account with BOC or can they be taken to, for example, a welding place and refilled or would I need to find a friendly landlord to exchange them for me?

I know someone who has several short BOC CO2 bottles for setting up temporary beer pumps for events and could get one from them but not sure how I'd get it refilled easily.

From looking around BOC are a bit of a pain as they still use a bottle rental scheme, so you need to pay a charge per month for the bottle. Other suppliers make a one-off deposit charge for the bottle, so there is no continuing payment. There are online suppliers, but they charge around £35 to £40 delivery for a 6.35kg/10 litre bottle.

https://www.bottlegases.co.uk/product-c ... ellar-gas/

https://gas-uk.co.uk/index.php/carbon-d ... litre.html

Locally I can buy CO2 from the local pub beer gas distributor. I just asked the landlady at my local where her gas came from and she gave me their number. I would guess that most places probably have a beer gas distributor fairly nearby. Only thing to watch with beer gas is that there are three or four different kinds of gas for beer. Some beers use a mix of CO2 and nitrogen, so you need to ask for pure CO2.

Another option might be to try Hobbyweld cylinders https://hobbyweld.co.uk/products/carbon ... ood-grade/ . Bit more expensive, but they seem to have a tie up with tool hire shops and they sell a dedicated CO2 beverage gas. Our local Sydenhams hire shop in Gillingham stocks Hobbyweld refills. You pay a deposit on the first bottle and then just pay the refill cost after that.