Argon beer, an alternative to the usual CO2 carbonation

Most beer is carbonated with 100% CO2. Some beers, notably Guinness and some other porter/stouts, contain a mixture of nitrogen and CO2 in a ratio commonly 75/25 N2/CO2. The nitrogen is less soluble in water, and allows the beer to be served at a higher pressure without dissolving too much gas into the beer itself. The higher serving pressure churns up the beer as it exits the spout, and creates a creamy head that is the signature of a good Guinness pour. Some pubs use 75/25 gas to push normally carbonated beers out of the tap, but the beers themselves contain only CO2.

In this video I wondered what would happen if I used argon instead of nitrogen. I started by using %100 argon since the solubility of Ar is between that of N2 and CO2. As it turns out, the Ar is not soluble enough to produce a decent head on the beer. Additionally, the complete lack of CO2 makes the beer taste sweet (like it's flat) since the CO2 is necessary to form carbonic acid in water, and this is an important flavor component of beer.

Xenon has anesthetic properties at atmospheric pressure, while the other noble gasses can become anesthetic at higher pressures. Does anyone want to explore xenon beer, or have any experience with xenon used as an anesthetic?

Three-way flow regulator for argon shielding gas

The serious TIG welders have two flow regulators on their argon supply -- one for the torch, and the other for the purge argon on the backside of the weld. I found some cheap flow regulators on eBay, and I made a manifold for the two I bought plus the original regulator. I've imagined situations where three regulators might be helpful like welding a gusset on the outside of a tank. The gusset would need backing gas in addition to the torch side, and the inside of the tank would need to be purged as well. Who knows.
I made the manifold itself out of a block of white Delrin with four 1/4-18 pipe threads cut into it. The original regulator (on the left) has 1/4-18 straight threads. I just ran my tap really deep into the Delrin so that the regulator would fit in. It's very easy to make metal fittings seal with Delrin and no Telfon tape is necessary. The Chinese argon pressure regulator also had a 1/4-18 female straight thread which was intended to seal on the end of the pipe. A regular 1/4" brass pipe thread nipple worked just fine and presumably bottomed out and sealed on its end.

Monster TIG nozzle = monster waste of money

UPDATE 6/15/2013: Arc-zone has redesigned their Monster TIG nozzle. It now has a chunk of rock wool or similar material to help diffuse the gas flow. I have never used this version, and so the comments in this blog post do not apply to it. Check the comments section for more details.


Today's lesson involves my quest to weld stainless steel sheet metal, a Monster TIG nozzle, and a copper chill bar. In previous posts, I've described having trouble maintaining weld bead quality on thin stainless sheets. The problems are a combination of putting too much heat into the metal, and having too little argon gas coverage. I am not sure if addressing one problem can help solve the other. Today, I did some testing to find out if adding a lot of gas coverage can help. I also tested out a copper chill bar.

Common weld parameters for the whole test:
1/16 ceriated tungsten ground to a sharp point
55 amps (pedal floored for the entire test)
very slight %90 pulse at 200Hz just to get my auto-darkening helmet to work
20 CFH pure argon
10 sec post-flow

I purposefully used a small piece of 304 1/16" sheet to show the heat buildup problems. I also welded close to the edge to test the worst-case heat buildup.

First up: normal gas lens with #8 cup.

Wow, I never knew the copper could help that much!

Next, a large diameter gas lens with #12 cup
Same story here. It looks like there was even less heat in the metal. This might be because there was better contact between the sheet and copper, or because the gas nozzle has a wider opening. I'll bet the Monster nozzle will be even better...

Finally, the "Monster TIG nozzle", which is 1" in diameter and uses a stubby gas lens collet body.
Wha?! There must be something wrong -- what's going on here?! I tried all gas flow settings from 5 CFH up to 30 CFH and concluded this nozzle is completely useless. It's possible that I am misunderstanding something since I am a new welder, but I am pretty sure this thing just plain doesn't work. I noticed that the tungsten had turned black after a few welds, indicating the gas coverage isn't even enough to keep the tunsten from oxidizing. At 30 CFH, the gas flow was so turbulent, I could see the arc getting blown around, and pops of smoke coming out of the weld. At lower flow settings, I could see the stainless oxidizing even before I lifted my hood. I tried different stickout from 1/8" up to 3/4" with no change. I am sure the cup made good contact with the torch body, and there were no air leaks. I even tried extending the nozzle away from the gas lens with a spacer to make sure there was adquate space for the gas to disperse with only a tiny improvement.

On the right: large gas lens with #12 cup. On the left, you guessed it, Monster suck.



This screen arrangement doesn't look so great.

It's made with just two screens without any spacers between them, and two very coarse screens on the outsides. The screen diameter is a few mm less than the interior diameter of the ceramic cup, so I'm guessing a lot of gas slips around the edges of the screens.
So, I'll be continuing my stainless welding quest without the Monster nozzle and with copper chill blocks. I'll also be testing Solar Flux B. So far, I think it works well but poses a huge cleanup mess after the welding is complete.

Bent TIG electrode = trailing shield?

Do you think this looks messed up?

Check out the welds that I can make with the messed up electrode. This is 1/16" 304:
I purposefully bent the electrode in the direction that I was moving the TIG torch. That way, there was a lot more gas coverage behind the arc than in front. It worked wonderfully! Even near the edge, the heat buildup was much less of a problem. I think the next step will be to make a trailing shield for the torch. Trailing shields are available, but only for amazingly high amounts of money. One alternative might be the "Monster nozzle". It could be large enough to act as a trailing shield.

First attemps at TIG welding stainless steel

I've spent most of my TIG welding practice time on aluminum, but have recently started to experiment with stainless steel (all 304 for now). It's difficult! Most welders say that aluminum is the most difficult because it liquefies quickly and has oxide layer problems, but in my opinion, stainless is more difficult because of the shield gas requirements.
Here's my setup:
.040" tungsten -- my local welding shop convinced me to try this instead of 1/16" tungsten. They somehow thought I could weld with less heat while using .040". I didn't understand it when they explained it so me, and I still don't -- especially since it makes no difference that I can tell.

no. 8 cup with gas lens

less than 1/4" stickout




Here's a 1/16" thick 304 sheet. The upper bead was done with 10CFH argon, the lower bead was 20 CFH. The picture shows the front and back of a simple bead with 1/16" filler. I was using as absolutely little heat as possible, sometimes solidifying the weld pool as I moved, making for an irregular bead. These beads both have major problems. They are pretty gray except on the left side where I finshed the weld and the post-flow cooled off the bead. The rest of the weld cooled outside of the gas shield, turning it gray, which is bad because the structure of the stainless steel has been altered. This will likely lead to corrosion or stress cracks.

I prepped the left side of the top surface to see if it would be any different than the un-prepped right side. The metal has a smooth almost plastic-like feel, so I was unsure if this was normal. It didn't seem to make any difference.

The backside shows major problems too. The upper bead looks better because there was more sheet metal all around the weld to soak up excess heat. The lower bead is "sugared" because it got very hot in an oxygen atmosphere. The weld is close to the edge of the sheet metal, so the heat built up more quickly.

To attempt to fix the topside problems, I've ordered a "large gas lens" setup with some huge gas cups from an online welding store. I tried to order these parts at my local welding shop, but they didn't have them, and were somewhat hesitant to even order them for me. I have no idea if the large gas lens will work, but the parts are relatively cheap.

To attempt to fix the backside problems, I've ordered some Solar Flux B, which was originally made for gas welding stainless steel. The alternative to flux is to build an argon purge for the backside of welds. This purge could be a box, a nozzle, or some other device to make sure the backside is flooded with argon. The problem is that every weld situation (tubes, sheet metal, angle, etc, etc) requires a custom purge setup, and argon isn't exactly cheap either. I'll definitely be posting more information about the flux in the coming weeks.


Here's a weld made on thicker (about 1/8") stainless. The grade of stainless is unknown. Don't mind the soot. I was just too lazy to regrind my tungsten after I hit it with the filler rod. Notice the bead is NOT gray. The thick metal is able to pull heat out quickly enough to prevent problems. Unfortunately, most of my stainless welding will be on tanks and tubes that will never be 1/8" thick. I need to find a solution that will work down to .049" at least.