is this welding lens right for the job ? (stick welding)

[cnc2]

Hi guys !

I bought a welding helmet (no name) and a couple glass lenses with 11 & 12 shades.

The lenses have the AULEKTRO brand printed on them like this:
AULEKTRO 11 FW 2 DIN GERMANY.
AULEKTRO 12 FW 2 DIN GERMANY.

After googling for AULEKTRO, i've found a website where there was no reference to the FW 2 type of lens, only FW 1 was mentioned, therefore I am worried if this lens is suitable for stick welding (smaw) it might be intended for torch welding/brazing or it might be a counterfeit part, and I want to be sure not to fry my eyes.

I did some testing of the lenses by looking at a lit light bulb, here are my observations:

1) By looking through the lens which came with the helmet & had no markings on it, the filament appeared reddish.

2) By looking through the AULEKTRO lenses, the filament appeared greenish yellow with a barley noticeable shade difference between the 11 and 12 shades.

Which lens seems to be a good one ?

I also did try to check the IR protection by using a remote control, and it only reduced its working distance and the remote was still working one or two meters away from the TV....isn't it supposed to block/filter ALL IR light ? the invisible beam of a remote control has a tiny power compared to stick welding light, is it normal ???

Please help, any input is welcome.

Thanks !
cnc2.

[wildwestpat]

The welding arc generates a load of ultra violet light as well as infra red. Both the IR and the UV cause of eye problems for welders and can lead to permanent blindness. There are some welding eye glass filters that have a sharper UV and IR cut with the intention of providing the welder with some vision prior to the arc being struck. These would give a greenish view BUT make sure what you have is suited to your intended use. However as you only get one chance get the correct filters from a reputable source and keep the receipt!

You also need to be aware that there are special lenses for uses other than hand welding so you are right to be cautious. (Inspection windows in automated machinery for example.) Get the right filters for the work you are doing including the arc power / materials and operating distance as the filters are cheap.

This document might help http://www.marcosta.com.pl/katalogi-...t-spawarki.pdf Table on page 84 might be of interest re choice of filter.

Regards - Pat

[cnc2]

Thanks for the reply & link Pat !

What do you mean by "have a sharper UV and IR cut" ?

Apart from the table I already saw elsewhere, page 84 showed a price list of welding lenses....I got two lenses for around 0.5 Eur :eek (German ???) while the cheapest lens on the list starts at 1.32 Eur....this means the seller got the welding lenses he sold me for about the price of cover (transparent) lenses ??? (0.15 to 0.20 Eur)

The number following FW in the code is an optical grade according to DIN EN 166, so my lenses are of grade 2, what does it mean ??? (googled DIN EN 166 & only found a PDF file on sell)

Thanks !
cnc2.

[wildwestpat]

The materials used to make the filters have a frequency versus attenuation characteristic and the eye also has a frequency sensitivity peaking in the green region. The filter characteristics are a balancing of the need to provide adequate reduction in the harmful effects of the arc's radiated power and leaving enough low level light to see the work before the arc is struck. The old style filters were very - very dark and it was difficult to see the work until the arc was struck - this was ok for the hand held shield and simple welds but for more sophisticated jobs better viewing is required before the arc is struck as well as providing protection against the harmful radiated power from the arc. This is why the filter needs a very sharp transition to maximum protection with frequency either side of the eyes most sensitive region as well as attenuating the light to a safe level. Put another way the filter needs to provide adequate (almost total block) of the frequencies either side of the green part of the spectrum and at the same time provide enough reduction in the green region to protect the eye from damage. This is why there are different filter frequency characteristics required for the different materials. In addition there are choices in density depending upon the distance between the eyes and the working arc.

As to price this relates to what the distributor can extract from the user rather than the intrinsic worth of the material. The normal terms and conditions of commercial supply could be expected to yield price breaks and discounts so that the indicated prices are not much use.

Also DIN EN 166 is a specification for impact rating. DIN EN 170 covers UV so I repeat my recommendation is to only buy from a reputable welding supplies outlet so that you know what you are going to rely on to protect your sight is correct for the sort of work you will be doing.

Regards Pat

[cnc2]

Thanks for the informative reply Pat !

Well, my biggest issue is locating a reputable/trustworthy supplier.

In the first place I was going to buy an auto darkening welding helmet from a local ESAB distributor...BUT... they were selling a no name low quality Chinese helmet for around $100 ...reading its characteristics showed that response time was <1ms, while most of the helmets today have a response time < 1/20'000ms ...we did try to test it but it never darkened when switched on :eek then the guy told me it would darken in front of a cigarette lighter (the stone scratching one not an electric/piezo lighter)...NADAAA ...may be it was because the guy didn't remove the protective film from the lens, but a battery operated helmet should darken to #4 when powered on.... I looked for an other supplier and found one who was selling an "Emporiki" welding helmet (made in Greece) for around $200... it turned out to be another no name Chinese helmet branded "Shine" AS2000-F...clearly over priced...A liar is a liar !

Is there a way of testing lenses ?

Is there a chart for lens selection with respect of the material being welded ? (will be welding steel for now)

Sorry if my English sounds weird.

Thanks !
cnc2.

[wildwestpat]

Try the attached document as it has a nice table that is easier to read than the one I previously posted.

I would avoid the cheap electronic shutter type as they are not fail safe and even then I would use the simple filters given a choice regardless of cost. It just feels wrong that the LCD is clear then activated by light from the welding arc to give the required filter density.

Regards - Pat

[cnc2]

Thanks Pat !

As I already told you, I have already seen different versions of that table around the net....What I don't know is hos to select the right lens according to the material being welded. For example what lens for welding stainless...etc.

I can't recall where i've first read about different lenses for different welded materials, but you reminded me about that by saying "This is why there are different filter frequency characteristics required for the different materials" in your post #4.....Am I getting it wrong & the only selection criteria is the welding current ???

Well, I've rolled the dice today and tried my first welds, just to see how it feels, my test was short (two 2.5mm rods) because of the untrusted welding lens. I used the AULEKTRO shade 12...I didn' think it would be bright behind such a dark lens...is it normal ? (not too bright to flash me though)

I have a 500A welder but I'm not sure it can do 500A because it is portable, small and light <30kg....I did my tests with the welder at its lowest setting...it has seven positions and I chose the lowest.

The three highest positions have an open circuit voltage of ~50V (weird !!! fake positions or what ?) the lowest position is at around 40V.

I think I'll get an ammeter to get the true numbers, and build a dimmer like circuit for more precise adjustments.

What do you think ?

I'll be looking for a lens which will make me more confident.

Thanks !
cnc2.

PS: while testing, I flashed myself once because I started the arc before lowering the lens...it was short but man that was bright !!!
Is that a common mistake ? any known consequences ???

[wildwestpat]

The tables I have suggested you use give the filter number against arc current and the material. Having decided to weld the filler rod and gauge of metal determine the current. Too high and you burn holes - too low and the filler is all bloby with no punch into the parts being joined. The type of equipment determines the flux and likely strength of the UV given off for a given current. The other big influence on filter strength creeps in when welding materials other than steel but these welds will also require special fluxes and probably protective gas shields where the suppliers recommendations should always be followed as there are a lot of variables but it is often practical to use the same filters as form steel at the given current.

By materials I was meaning the welding rod / wire and the flux rather than the metals being joined as far as I am aware the materials being joined have a lesser effect than the current and flux/filler combo but I am not an expert and take the advice of the supplier of the welding sundries (materials) wire - rods etc.

However if you are going to be welding a lot the actual rod suppliers advice should be followed as these tables are a general guide as distance and material do have an effect but to a lesser extent than the actual arc current.

As far as I am aware the effect of flashing the eye is an intense irritation (itching burning sensation) that occurs some hours latter and does not go away. I only have this third hand as I am cautious by nature and prefer brazing to welding.

The open circuit voltage is not a guide to the current available. The open circuit voltage needs to be high enough to start the arc and 40 volts plus is going to be enough for average cleaning of metal components prior to being welded. Many welding equipments supply a superimposed alternating voltage onto the electrode to help breakdown any oxide film but the auxiliary (superimposed) voltage plays no part in the production of the molten metal. The control of the arc current is done by a variety of means depending upon the type of equipment. Some are electronic and other rely on the magnetic circuit of the transformer or additional resistance / inductance. Each type of equipment has advantages under certain circumstances and there is not a one size fits all.

Hope this gives you the information you need to select the best filter to protect your vision whilst at the same time giving adequate vision to see the work prior to the arc being struck. I find it helpful to use 1000 watt QI lamps on stands to give easy vision with goggles on prior to any welding.

Regards - Pat

PS you need goggles for brazing.

[cnc2]

So, by welding material you was meaning welding process, confusion cleared.

Thanks for the QI lamps tip, I did my first welds in a garage under a 75 or 100W incandescent lamp & kept opening & closing the lens's "window" to be able to position the rod, & once, before I lowered the lens the rod touched the workpiece...when the lens is up, the arc always starts properly just to flash you

Thankfully I'm fine, no scratching eyes...it felt a tiny weeny weird a few hours later, I don't know if it was psychical, but just to avoid the scratching "sand" in the eye problem, I looked at a neon tube for some seconds, just to stay on the safe side.

Thanks for all the help !
cnc2.