what kind of glass to use

By sparmer Date 06-11-2001 20:26

I'm trying to find out what kind of glass should be used for windows that lookout from offices into a shop area where welding occurs. The office manager likes the idea of being able to see the work being done in the shop.
I'm concerned about eye injury and welding flashes. I know that welding torches also give off infra-red light that can harm eyes.
Caplan Bros. Glass said they had a "blackout" film that could be added to glass to darken it up, that it would be less expensive than glass, but having never used glass in this situation before, they were reluctant to give a recommendation. Just darkening the glass may not help.
Should glass be used at all in this situation?
Does anyone have any suggestions of how visibility into the shop can be provided without harming the observers?

By RonG

Date 06-11-2001 20:54

If you intend to look at Arc welding you need at least a No# 10 filter but whats the point? If you are not with in inches of the work you will maybe see a pin point of light only.

If you do only Oxy-Fuel welding / cutting a No# 6 is good but the same as above applys.

If you darken the glass a few shades (No# 3) plus far enough away and do not stand and stare at the arc you might get the effect you want but is it worth liability?

Inform your Office Manager that welding is not a spectator sport and the eye damage (flash burn) is very painful.

By bhiltz

Date 06-12-2001 22:35

How far away from the arc are you? I believe i read somewhere that about 20ft is a safe distance? Good safety glasses have uv protection, not from direct uv light within inches but uv from a distance ,maybe you can get this in a sheet to replace your glass?

By boilermaker (**)

Date 07-02-2001 21:17

A safe distance is 50 feet.

By HappyWelder (*)

Date 06-14-2001 15:27

The only way your pointy-haired boss is going to avoid
being disturbed by annoying arcs is to use a glass dark enough to
black out everything else.

/Happy

By John H. UK (*)

Date 07-06-2001 00:15

IR is most definitly not the danger involved in arc flashes and oxy./fuel torches, it's UV. UV is an ionising type of radiation that will pass into your boss' eyes and give him cataracs. Sevior arc flash burns the retina of the eye. This was discussed a while ago about how dark a welding visor should be. A point raised was that all welding lenses, no matter what darkness, filter just as much UV and IR radiation as each other. A number 6 filters no more and no less than a number 13. The number indicates how much of the other radiation it filters. A number 13 will filter as much of it as it can so you are not blinded by the visual intensity of the arc, so you can see what you're doing. A number 6 filter much less so you can see quite a lot, the flame's visual intensity is quite low.

As for the glass I'm not sure where you could get it from. I'm sure there must be places somewhere that sell UV covers for glass and plastics, or ones you can spray on out a can. If the office is far enough away darkened glass alone may just be enough. If it's far enough away the intensity of the UV might quite possibly be low enough for it to be absorbed entirely in the glasses dark layer. So long as he isn't planning on eating his lunch while he watches his workers weld I don't think there's any harm in using a piece of normal glass.

By Lawrence (*****)

Date 07-09-2001 17:21

That Ol Boss of yours needs curtains at the welding stations. There are several different varieties, colors and shades which can be portable and placed between the welding arc and the crystal palace <his office>. This way he can sit in the office and smoke his Cigars whilst watching the toils or timing the coffee breaks of those in the shop. Most Bosses are happy just to know the arc is struck and are satisfied with the muted glow emanating from behind the opaque safety screen. Rarely are they interested in technique or intimate details of the project at hand.

Here are some links you may find of value

http://www.traxindprod.com/welding/welding.html <--One of many online vendors

http://www.osha-slc.gov/OshStd_data/1910_0252.html <---OSHA welding safety page containing info on screens.

http://www.osha-slc.gov/OshDoc/Interp_data/I19780317.html <---a related OSHA compliance letter