Flipping Down Right: Using a Passive Welding Helmet

Part 1: Why use a passive helmet?
There are two types of helmets or hoods for arc welding: active and passive.
The active kind is auto-darkening; the lens starts out at a light shade (often shade #3), but when an arc is struck in front of it, the lens darkens (usually to a shade between #8 and #12). The darkening happens within a tiny fraction of a second–between 1/5,000 and 1/20,000 seconds.
Passive hoods are much simpler–the lens is always a dark shade like #10, and the user “flips” the hood down immediately prior to striking an arc. Looking through a passive hood, it generally looks completely opaque all the time, unless you’re looking at a bright light.
  • Passive hoods are cheaper.
    Fifty dollars will buy a passive hood that will likely last the rest of one’s life. I’m a big fan of the Jackson HSL-100. Even a high-end passive hood typically costs well under $100. They never need batteries. Fifty-dollar auto hoods are available, but they are far less durable than $50 passive hoods. Decent auto hoods start at around $80, and go up to many hundreds of dollars.
  • Passive hoods generally give a better view of the arc.
    I can weld just fine with my $200 Miller Performance auto helmet, but the view of the arc is a little clearer, and colors are rendered a little more realistically, with my $50 passive hood. More expensive auto hoods supposedly have better color rendition, but at a cost 5 or 10 times as much as a $50 passive hood. Further, a $50 passive hood has an industry-standard 4.5″ x 5.25″ viewing window–that’s 23.6 sq. inches, versus 9.2 sq. inches on Miller’s high-end auto-darkening Digital Elite hoods. Granted, a large viewing area is more of a necessity when using a passive hood than when using an auto-darkening, but it’s also just nice to be able to see a larger area.
  • Passive hoods are more reliable.
    There are a number of things that can go wrong with an auto hood–batteries wearing out and electronics being damaged by temperature or moisture are just the start. An auto hood has a limited number of sensors that “see” the arc and “tell” the lens to darken. It’s possible that one or more of these sensors can become blocked, such that the user can see the arc, but the sensor(s) cannot, causing an uncomfortable, distracting arc flash for the user. Pricier helmets have more sensors (typically up to four) to help mitigate this risk. Furthermore, these sensors must be sensitive enough that even low-amp welding will trip them, but not so sensitive that they trip due to exposure to lights indoors or sun reflections outdoors. This is a problem the helmet manufacturers have been working on for a while now, and again, pricier helmets have solutions like sensitivity adjustment dials and even modes that sense when an arc is struck by non-visual methods (e.g. Miller’s X-mode). Passive helmets work regardless of any blockages, and at any current level.

Despite all this, I own a Miller Performance auto-darkening helmet, which I use and recommend. Auto hoods are especially good for precise TIG work (where even the most careful flip-down might damage or move the work) and repetitive operations like tacking (flipping down 100 times an hour is time-consuming, tedious, and hard on the neck). They also come in handy when a passive hood simply won’t fit–I once had to weld on some I-beams in a house under construction; I was working so close to the ceiling that a passive hood would’ve made things even more difficult and cramped.

I also own a Jackson HSL-100 passive hood. I use it once in a while, partly to be sure I don’t forget how to use it. And I keep it around just in case my Performance fails, breaks, or runs out of batteries.

The two types of hoods are different tools for different applications. Ideally every welder would know how to use each. This article focuses on passive hoods, because nobody else seemed to be writing about them, and because auto hoods vary considerably more than passive hoods do.

Part 2: Setting up the passive hood

jackson headgear
This is the current (as of May 2013) headgear included with new Jackson HSL-100 passive welding helmets. I like this particular headgear–it’s simple, durable, and comfortable–but all headgear has roughly the same functions.
The big red knob that sits at the back of the user’s head and allows the user to fit the helmet to their head circumference or hat size.
  • The hat size adjustment is too loose when the hood falls off the wearer’s head during flip-down.
  • The hat size adjustment is too tight when it causes discomfort.
  • The user should have to loosen the hat size adjustment knob in order to remove the helmet.

The crown adjustment controls how high the headgear sits on the user’s head.

  • If the headgear sits too high on the user’s head, it can be impossible to keep the hood on the head during flip-down.
  • If the headgear sits too low, it can get in the way of safety glasses (which should always be worn under a welding helmet) or become uncomfortable when tightened.
  • Generally the front of the headgear should sit just above the eyebrows, where the skull narrows slightly.

The tension adjustment knobs control the speed of the flip-down.

  • They are both right-hand threaded (“righty tighty, lefty loosey”), and should always be adjusted in concert.
  • Should be set loose enough that the user can achieve a fast flip-down with minimal effort or movement. The helmet should come down quickly.
  • If the tension screws are set properly, the flip-down requires the use of only a few small muscles in the neck. The less the neck and head move during the flip-down, the less likely the hands are to move.
  • They are set too loose when the hood flips down on its own.
  • Even once adjusted perfectly, tension screws may need to be readjusted for a number of reasons, such as welding position–i.e. different tension may be required if welding in horizontal position (2G) versus in flat position (1G).
Part 3: Using the passive hood
  • The ideal flip-down is one in which the user’s hands remain exactly where they were prior to the flip-down.
  • The goal, therefore, is to keep the body motionless except for the neck.
  • The flip-down should not require much effort. Welding work is often hard work, and the flip-down shouldn’t add to user fatigue any more than necessary.
  • It’s a flip-down, not an up-then-down. Lifting the head up before nodding it down is usually a sign that the tension screws are too tight. An up-then-down motion can also take the user’s eyes off the work, which is sub-optimal.
  • Never use a hand to lower a passive hood. It’s a bad habit to get into. One can barely, sorta, kinda get away with flipping down by hand in some applications (chiefly GMAW), but not many. Learning to flip down well is part of learning to weld; starting with good habits shortens the process.
  • Good helmets (including the Jackson HSL-100) have a detent that locks the helmet in the flipped-up position. This feature should be used every time–that is, the helmet should be lifted all the way up so that it clicks and stays in place. The detent is immensely helpful in preventing the helmet from accidentally flipping down, especially when the user bends over to look down at a weldment on a table.
Part 4: Everything else
Your helmet is yours
If you’re serious about this welding thing, you need your own hood.
Don’t delay
Beginner welders often flip the hood down, then delay striking the arc for a few seconds. But with the hood down, the user can’t see anything–there is little to be gained when the user is “flying blind” like this. I tell beginners to think of the flip-down as occurring while they’re on the way to starting the arc; the finger should already be on the MIG gun trigger, or the foot on the TIG pedal. Prior to flipping down, everything should be ready for welding to begin, except that the hood is up instead of down. As soon as the hood comes flipping down, the arc should be struck. The only exception is if the welder detects that the flip-down was unsatisfactory, usually meaning that the hands moved (more on this below).
Process-specific tips
GMAW:
  • The tip of the electrode wire should generally be touching the work prior to and during flip-down.
  • Friction between the tip of the wire and the work can help in preventing movement of the torch during flip-down.
  • If the hands move slightly during flip-down, the user can sometimes use the tip of the wire to “feel” for the start location, e.g. the gap between two plates.

GTAW:

  • Unless scratch-start or lift-start is used, the electrode should never touch the work.
  • If in doubt, prior to depressing the pedal, the user can touch the electrode to the work (again, possibly “feeling” for the start location with the tip of the tungsten), then lift the electrode slightly before depressing the pedal to start the arc.
  • Advanced tip: Flashlight mode. When using a foot pedal for non-critical applications, the arc can be struck and kept at low amperage, then guided to the desired start location using the arc as a light source. Keeping the amps low (pedal barely depressed enough to keep the arc lit) helps prevent discontinuities like arc strikes, which are especially troublesome of crack-prone materials. This technique is undesirable for critical applications.

Get a sweatband
sweatband
This is a leather sweatband for welding helmets. It installs on the front of the headband in a couple seconds and is worth its weight in gold when doing any significant amount of welding work. Tillman makes this one, which is well worth the $2 asking price. Black Stallion/Revco also makes a cotton one. The foam typically sold with a helmet, even a nice one, is engineered for low cost, not comfort.

Seriously, get a $2 leather sweatband. Your helmet will feel more comfortable, espeically when it’s hot out.

Get a gold lens
For things like precision TIG, a gold lens is the gold standard of arc visibility. I like to say that looking at a TIG arc through a gold lens is like looking into the soul of the arc. Instead of the green or blue tint of a normal lens, colors look nearly true-to-life through a gold lens. But the difference between an auto-dark lens and a typical green passive lens is bigger, to me, than the difference between a green passive and a gold passive lens. It’s nice to have, but not a necessity for every welder.

Practice

Learning to flip-down a passive hood properly takes patience and practice. Even after years of welding, some flip-downs will go poorly; this is not a cause of great concern. It takes only a second to lift the hood up, evaluate what went wrong, and try again. Within a few minutes of learning how, almost anyone can set up and use a passive hood like a pro.