For those who are familiar with gas welding aluminum, I was curious about the lenses you use. There are a few different lenses out there and I wanted to separate the financial interest in selling expensive lenses with what works well enough. I wouldn't mind playing with it just so I can say I can, but I wanted to be properly equipped for the process. Are certain rods needed for different alloys for general purpose stuff or will one or two do for most kinds? How do you know what alloy you have?
As best I can tell, the authority on this subject is the "Tin Man" guy. He sort of "Re-invented" gas welding of aluminum after the world almost forgot it could be done.
And apparently, he has built himself quite an empire. He markets a green lens that he claims is the best to be had. Back during WWII when aircraft aluminum components were gas welded, people used a blue lens. I can't remember what it was called. I wanna say "duodenum" but I think that's part of the anatomy of the stomach...
Anyway, all the above is simply me regurgitating what I read on his web site several years ago. At that time I bought one of his expensive lenses and I still have it.
But I've never used it. According to the "Tin Man" the issue is that the flux incandesces a brilliant yellow which is quite injurious to the eyes. He claims that the "duodenum" lenses do not adequately protect against this.
I hope I haven't mis-stated anything the Tin Man says in his web page. But I repeat it's been several years since I've thought about this.
And I h> For those who are familiar with gas welding aluminum, I was curious
"Vernon" wrote: (clip) people used a blue lens. I can't remember what it was called. (clip)the issue is that the flux incandesces a brilliant yellow which is quite injurious to the eyes. ^^^^^^^^^^^^^^^^^^^ Those blue lenses were cobalt glass, and they did a wonderful job of cutting the bright yellow light. I don't think it was the yellow that was harmful, but it made the weld area hard to see, since it was brighter than anything else. The word was that the cobalt glass allowed harmful UV to get through, and they were outlawed. If the "Tin Man" has a replacement, I'd love to try it.
if you have the money (for these things are still expensive) then the best filters to have are a dielectric coating, not a doped glass. By coating multiple quarter-wavelength thickness coatings onto the surface you can make a magic filter that can reflect any chosen wavelength. As the problem wavelengths are generally well known (they're the spectral lines of elements in the flux) then this allows a filter that blocks those effectively, yet still allows as much light as possible from the other wavelengths, improving general vision. However they're not cheap.
Years ago I used to work with lasers. Bulk glasses and dielectric coatings both proteted you equally well, but one also allowed you to walk around a dark lab without bumping into the furniture.
In astronomical purposes, many layers are overladed each with unique pass and block ability. The idea is to kill the Sodium light - easy a two color - two frequencies to block. A small block band would do it. Mercury on the other hand has many lines of color. and in some important regions.
One would want a UV cut (remember camera filters have this) and another for cutting back other colors.
The overall cut back is gray - chops a broad spectrum. The specks of black absorb light.
So if one had a good lens for this but not for that - adding another lens might be the ticket.
Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder
Glass without grounded metal sheet NEVER kills EM waves - Electro-Magnetic waves sail through most things. Light particles and light waves (point of view ) are blocked and passed depending on wavelength.
The blues one could be used if they were one of perhaps several glasses looked through. And that is that. The reason they were banned was safety. Types like you would not follow instructions or couldn't see this or that and would burn out rods or cones.
Martin Martin Eastburn @ home at Lions' Lair with our computer lionslair at consolidated dot net NRA LOH, NRA Life NRA Second Amendment Task Force Charter Founder
Rod: Cobalt is a magnetic material. It cannot block EM Waves. But as you point out, if you *GROUND* the cobalt lense, then it is safe. Or again as you point out, use a non magnetic lense in conjuction with the cobalt non grounded lense. So, we're on the same page, basically.
-- Rod Ryker... The intricacies of nature is man's cannon fodder.