Large Welding Lens

Date 12-24-2002 00:55

Try STANDARD Welders Supply in Memphis, TN. 901-523-6836 talk to Tommy Howell if he can't find it, it's not made.
Faron Breaux

By Wildturkey (**)

Date 12-24-2002 13:13

Luke, I believe that the standard large size lens is 4.5" x 5.25" and can be purchased at any local welding supply.

By dee

Date 12-25-2002 05:37

If you are looking for two FEET by three FEET shade 10 or 11 filters you might consider combining lighter ones to achieve a darker filter...

Rohm & Haas used to make a product gnerically described (incorrectly) as Plexiglass in a variety of tints. GE may be able to help with Lexan sheet... a plastic supply house outside of the welding industry might help...

A few decades ago I had Mylar samples (like the silver plastic baloons) of various film thicknesses and with various densities of metalization; the greater the metalization the less light it transmitted. Even the heaviest film thickness might be too thin for your purpose except perhaps as a suppliment to another filter...

I'd be concerned about knowing UV transmissiveness of the material you select as a substitute and how to CYA without ANSI cert on a home brew filter; supplementing behind a filter already designed for welding might be a more prudent option if you are unsure of all the safety considerations.

regards,
d

By Wildturkey (**)

Date 12-31-2002 13:42

Sorry about the first reply Luke. I now see that you require 2' x 3' not inches. I must have been reading fast. Dee suggested the Plexiglas, which may very well work. Just make sure that the UV protection is there. But I have been told that doubling lenses is not a good idea. I have searched everywhere for something to confirm what I have been told and have not found anything.

By CHGuilford (****)

Date 12-31-2002 14:13

A couple of years, my eye doctor told me he was able to tint polycarbonate lenses to make sunglasses. I don't know how it's done but I was thinking it may be possible to use the process on larger sheets of plexiglass or Lexan? I'll see if I can find some info but you might find it worth asking a local optical supplier about it.
CHGuilford

By dee

Date 12-31-2002 19:51

CH,
I regret that I'm unaware of the composition of standard lenses for welding helmets. I have suspicions but don't know for sure if it's the polycarbonate material itself that provides the UV filtering; I'm sure there is a supply source for plastic sheet that can provide same in a variety of tinted shades off-the-shelf. I cant advise about materials- that's out of my area.

I'm also concerned about the heads-up about doubling up tinted lenses. I think I got the impression it was OK from Jackson instructions or perhaps comments online around here somewhere in the context of adjusting fixed shade automatic safety lenses ("blinkers")... reasoning behind any possible hazards escapes me. Any insights on the subject would be appreciated. Every shield should have more than one lense in it (and the wearer should also use safety glasses behind it)- I understand the suggestion is that only one of the combo should be tinted? If it's a mounting or restraining design issue for impact protection in a portable face shield this would not pertain to the design of a window, would it?

regards
d

By CHGuilford (****)

Date 01-01-2003 13:31

Dee,
Actually, my thinking was not about any specific number of layers of material. Just that tinting is possible on a small scale, so I would think someone might do it on larger sheets, and it might be commercially available. Also, I would think an optical materials supplier would be better able answer questions about UV tranmissivity (is that really a word?)
I don't know why you can't have more than one of the combo tinted, just that normally one plate gives the protection needed. I like to use a shade 14 when welding with FCAW at 250+ amps. We don't usually have them in the tool room, so I combine a #10 with a #4 or #5 burning lense. I don't know if that gives me a #14 or #15 but I know my eyes like it better at the end of the day.
I think the idea of every shield needing more that one lense comes from using glass filter plates for welding, that they can shatter from impact or from heat encountered in welding. The plastic cover plates are cheap insurance against injury and keep the more expensive filter plate from getting spatter stuck to it. (I know that you and most everyone else already know this, just mentioning it for those who might not.)
But all this is interesting and if suitable UV filtering materials can be found in large sheets, I can think of a few applications in the company I work for.
As far as mounting goes, we're limited only by our imagination.
CHG

By dee

Date 01-02-2003 19:39

CH,
I appreciate your response. Your rationale seems to be good as to transmissivity data- BTW the word does stem from "transmissive" and at least it exists now- of plastic; I'd expect opticians to know, but my faith and trust remains in the engineers in the plastic industry; the manufacturers know and are willing to share such information about their specific product. 30 years ago I had these kinds of transmissivity specs from a company that manufactured metalized mylar, other films, and sheet; it's long-gone now but was extremely- and I mean thoroughly- detailed. If it was still around I'd share it. I have a few options I'm looking deper into as well for info for you guys.

My recollection is becoming fuzzy with age, but I seem to recall (note the word "seem" is not being used as a trite embellishment- it means I'm not 100% sure) reading directions from a newer all plastic shield that (ANSI or whomever) safety certification of the shield could not be insured without a clear lense both inside and outside of the tinted lense, and that safety galsses were also required and a pair came in the same box. I thought it curious but never pursued it further for verification... I figure if anything gets past the safety glasses I probably have more serious problems anyway, so what the heck- I guess it's a tad reckless not to really know.

You'll find the stuff.

Have a happy 03
d

By DGXL

Date 01-02-2003 21:06

Luke:
Many different ideas here, here are a few more:

We used "special curtains" when I worked aerospace and was learning LBW. They were very effective, and were not manufactured by the other welding curtain companies. They were designed specifically for various LBW applications. They were darker than a number 8 shade (I'm pretty sure - but not positive), because you could not see anything through these unless welding was taking place. That was 15 years ago as well.

Another option:
One of my clients installed small "doors" that would slide over the work areas of a welding lathe we designed. They did not need to watch the weld either, just periodically monitor the machine during operation. 2 welds were performed simultaneously using GMAW-P, very intense arc times 2.
While in Asia, I noticed nobody wears a hood, automated/mechanized welding equipment used the "door" methodology of protection. A part was loaded, door closed, button pushed, door open, part removed. (Quite efficient actually for the types of products being manufactured.)

I will be performing audits at 2 manufacturers of the sheet products within the next couple of weeks. If you post your e-mail addy, I can forward their respective addys and you can ask them yourself. I know they test for UV protection/transmission, but not sure to what extent. It depends on the intended application for the panels.

By Luke10 Date 01-06-2003 19:41

Thanks for all of the handy tips. I have sure learned a lot about lens. I am concerned about the safety aspect (shatter and UV) of the lens. Because of this I am hesitant to try to tint different materials and would rather have a welding lens. I did entensive searches on curtain lens and found that they only come in shade 8. We tried putting two shade 8 together, but it was too dark.

I finally found that Mack Products make custom size welding lens. The largest being 20" by 40". I have decided to pursue that route.

Thanks for everyones advice.

By BobbyN Date 12-11-2017 16:40

Is there an address for Mack Products?

BobbyN