Oxygen

[stronk]

Just wondering what you guys mean when you say 'oxygenate'. I'm in a diving club and have been reading up on oxygen regulators and compressed oxygen and it's not happy reading! Basically, you need to get the tanks visually inspected very often (I think it may be once every 2 years, but don't quote me on that) and the regs and other fittings need to be specially oxygen-inspected and sealed.

Is there any homebrewer out there who's pumping pure oxygen into his wort for aeration? If so, are you doing it safely? If not, you can have a runaway oxidation reaction with the tank or reg and end up with either a lot of molten metal and oxide or a large hole in your roof.

Or is 'oxygenating' really just the wrong word for 'aerating'?

[danno]

Originally posted by stronk
Or is 'oxygenating' really just the wrong word for 'aerating'? nope, two different things... I (and I'm going to assume most brewers who oxygenate) use small disposable welding cylinders like these (http://www.bernzomatic.com/bernzomatic/consumer/jhtml/detail.jhtml?prodId=BernzoProd100033). I get about a dozen batches out of each tank, they run about $5 at my local mega-hardware store... you attach one of these (http://www.northernbrewer.com/pics/fullsize/Oxynator.jpg) to the tank, and that's it...

(edit: yowza! those have gotten expensive! $52 for the regulator and stone? I think I paid $30 for mine a couple of years ago...)

(edit again: interestingly, on Bernz-O-Matic's UK page (http://www.bernzomatic.co.uk/selection_guide.html), it doesn't appear they offer o2 tanks. could be differing regulatory stuff...)

[Mill Rat]

Seconding Danno, aerating and oxygenating are two different things. I oxygenate because it was cheaper for me to grab the oxygen bottle from my welding rig, chop a gas hose (the green one) in two, and stick a sintered stainless steel aeration stone in the cut end than do all the farting about with aquarium pumps, activated carbon, micro-filters, etc. We're discussing three types of O2 cylinders here:

The little Bernzomatic cylinders, which is what I think Danno is referring to. These are simply propane DOT-3 cylinders with reverse threads on the fitting, gassed up to their pressure limit. These are rather expensive for the amount of O2 you get, but readily available and convenient. The valve to screw on the top of one of these little tinfoil tanks also costs considerably less than a good two-gauge O2 regulator.

The standard gas welding tanks, which are the heavy cast steel bottles with the heavy brass regulator. This is certainly the most economical source of O2 if you've already bought the welding rig. I've been using a small cylinder (~2' tall) for oxygenating and have not really put much of a dent into the gas inside. The disadvantage to these is that the suckers are heavy. A diver with one of these on his or her back wouldn't need a weight belt. For brewing, this weight isn't a factor. These tanks have dated labels on them and are pressure-tested at industry-standard intervals when you exchange them for refills.

Diver's tanks and regulators are rather more expensive and delicate because they're meant to be submerged (which would certainly damage the welder's tank regulator) and are made of lighter (thinner) materials so the diver can get back to the surface with the tank still on their back. These are also more rigorously inspected because they have certain life-safety aspects to their use. They're very similar to fire department SCBA systems.

The other difference I see with these systems is that the DOT-3 and welder's tanks are industrial-grade O2, while the divers' and fire SCBA systems are medical grade. According to Jim Ebel at Two Brothers Brewing, they oxygenate their wort using medical-grade O2. They don't use industrial grade because of NSF standards. Jim said they had previously used a food-grade bottled oxygen, which was between the industrial and medical grades in both purity and price, but that this grade was removed from the market a few years back when the "oxygen" bars were popular. I'll bet the big gas producers like BOC and Linde wanted to get away from the liability that might come from a person getting over-oxygenated at such a bar that had far shallower insurance pockets than they did, and the "victim" getting most of their compensation from the gas producer.

Personally, I do not think the industrial grade is any concern as long as you're not inhaling it directly. After a week of vigorous fermentation to strip most of the volatile compounds out of the wort/beer, I doubt that anything that came over from the O2 bottle remains in the beer. Certainly though, from the perspective of someone like Jim who has his product up for sale (and the liability risks), certification that everything that touched the product was food-grade pure or better is a wise investment.

[corkybstewart]

I was just asking about this at my local welding supply store last week. I can buy a tank for $90 or lease one for $45/year, that's kind of a no brainer, and to fill it would be around $8. What was interesting was that while I was down ther to get my CO2 tank filled they were filling medical O2 bottles. I think the difference is, and I may be mistaken, the medical O2 goes into stainless bottles and the welding O2 goes into steel. The owner said that for what I want to do a standard CO2 regulator is all I need so before I brew again I'll probably buy a bottle of O2.

Here's a related question: Do I inject it on the hot or cool side of the CFC?

Here I can't buy the medical O2 without a prescription.

[danno]

cool side. i oxygenate when I pitch my yeast...

[Mill Rat]

Originally posted by corkybstewart
The owner said that for what I want to do a standard CO2 regulator is all I need. I hafta disagree here. Pure oxygen is fairly nasty stuff. I would not want to bet my house that the gasketing, diaphragm, and seals in a CO2 regulator will withstand long-term exposure to pure O2, nor would I think it worth the time to research and ensure that fact instead of just buying a regulator built for O2. I've seen problems in industrial O2 systems (at steel mills) where the wrong materials for gaskets and seal lubrication resulted in some rather spectacular unintended consequences.

Originally posted by corkybstewart
Here's a related question: Do I inject it on the hot or cool side of the CFC?Just like CO2, O2 will dissolve far more readily in a cool liquid than a hot one.

[DecoJuicer]

I'm with Mill Rat on this one.

When I worked in the dive shop, we had several large O2 tanks for doing Nitrox blends. In order to fill somebodies tank above a certain percentage of O2, they needed to be able to provide proof that the last time that they had the tank certified, it was certified O2 safe.

That required special cleaning and gaskets. Also, you could not use ANY petroleum based lubes on O2 cleaned tanks. Silicon based lubricants only. All gaskets, diaphragms, and lubes MUST be silicon. Oxygen and petroleum based products don't mix very well.

I know several people who would often fill bottles that were used STRICTLY for decompression stops with very high levels of oxygen. This helps to remove nitrogen from your blood much faster, therefor allowing shorted deco stops.

I should remark, that this is NOT acceptable unless you have had the proper training.

We ended up spending a little bit of extra money and started installing silicone gaskets in all of the tanks that we service, and only used silicone lubricant. It cost us a few cents more per tank(actually close to a dollar), but you only need to see the damage that a full O2 tank can cause to a building once. After that, you tend to be very careful how you play with oxygen.

[stronk]

^

That's pretty much what I was referring to. Just be careful with pure, compressed O2. I personally wouldn't trust that reg danno posted further than I could spit it.

[danno]

Originally posted by stronk
I personally wouldn't trust that reg danno posted further than I could spit it. on liquid o2, I'm in complete agreement with you. but for what it's designed for, compressed gaseous o2, it works just fine...

[Mill Rat]

Originally posted by danno
on liquid o2, I'm in complete agreement with you. but for what it's designed for, compressed gaseous o2, it works just fine... Danno's OK on this. This is designed for and will only fit the little DOT-3 (propane torch style) O2 tanks that'll run out in 10 minutes if you try to do any welding with them, and 2 minutes if you try to do any cutting. For oxygenating wort, they're OK, even if the oxygen in them is rather expensive on a per use basis. It'll take you a hell of a lot of batches of beer to amortize the additional capital cost of welding rig equipment like I use to the point that it's competitive on its own with the Bernzo tanks (not to say that I ain't trying!). However, if you bought the serious tanks and regulators for welding like I did, it's all gravy when you use them for oxygenating, too.

[Mill Rat]

Originally posted by corkybstewart
What was interesting was that while I was down ther to get my CO2 tank filled they were filling medical O2 bottles. I think the difference is, and I may be mistaken, the medical O2 goes into stainless bottles and the welding O2 goes into steel. I was re-reading this, and I think one additional difference is that the medical O2 tanks are much lighter than the welders' tanks. If I were in such weak shape that I needed O2, I'm not sure that lugging around a cart with a five-foot tall heavy steel industrial cylinder would be in my best interest!

[Chubber]

I am also getting ready to purchase an oxy rig. I am using a HEPA filter and an air pump right now.

The Bernzo tanks are good and all, but the little valve for the top is crazy expensive. $50 for the top when it is no different than a $5 propane torch head, but with reverse threads is crazy.

I keep my eyes peeled on Craigslist and the like for real Oxy/Acel welding rigs. A big tank of that should last the rest of my natural born life. And I can weld with it. Huzzah.

I was visiting my mother-in-law last week and she is now on medical oxygen from time to time. She has these cool little aluminum bottles that are about 12 inches tall, but filled to 2000 psi, enough for a free flow of oxygen for 2-3 hours she said. She had about 10 of them around the house, she says the people keep bringing them, but never pick them up. I don't know what the top regulator costs, but if I lived near her, I would just "borrow" a full tank from time to time and it would last me a year. I just don't think that I could take that tank on the airplane with me.

Before I spend $50-60 on an oxygenator kit, I might buy one of these:
Small Welding Torch (http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=3687)

At least you could braze and weld (kind of) when not using it for beer.

[chapesh]

i am a f.f. and can attest that 02 and petroleum products add up to a fire. a very big fire. with lots of booming going on and tanks turning in to missles. however that aside how about using a regulator and medical o2? i have actually thought about this. the medical regulators can provide various liter of o2 as well,2l-25l. the only reason i don't do this right now is i don't seem to have a problem with areation, is there a signifigant reason to use o2? i have read articles that state a certain amount of trub can provide the same benefits as o2 for the yeast.

[Mill Rat]

I use O2 because it was cheaper and easier for me to do that than to put together the whole aquarium pump-HEPA setup. I have noticed it does cut lag time and primary full-bore fermentation time.

As for "and tanks turning in to missles," that reminds me of the big reline of No. 7 blast furnace at Inland Steel back around 1990. Seems someone came up with a rig to put the O2 bottles on a ramp with a trip hammer that knocked the valves off. Launched a bunch of those puppies into Lake Mich. Got caught when their improvised artillery devices came too close to one of the ore boats. Turned out to be profitable to hire a diver to rescue them and return them. They found a bunch of really old ones, too, probably from the original construction.

[texasliam]

I know a distressed medical suply buyer (used stuff) that gave me an outdated oxygen concentrator. Makes O2 at about 90%
Looks like this
http://www.home-med-equip.com/oxygen-concentrator/303ds.html

works great
Liam

[Spicoli]

I use one of the green oxygen tanks with my stone for oxygenating. Way more economical than the red cans from HD. I have used mine for about a year now and have not even put a dent in it. Around here the gas suppliers make you have different valves for each gas so not to give someone the wrong stuff. I had to get a new valve installed on one of my Co2 tanks for my new nitro setup. Nothing is interchangeable. The regs can get pricy also.