Welding Galvanized Pipe

Date 11-17-2002 17:42

You should probably find out more about what product they manufacture. Although the ad said "galvanized pipe", they may be applying the galvanizing after the welding is finished. If that were the case, there would not be much cause for concern. However, if that is not the case you would certainly want to find out during the job interview and have them explain the safety precautions they follow. If the work were indoors, there definitely should be a good fume removal system at each workstation and/or removal of the galvanizing in the weld area prior to welding. Outdoors about all you can do is remove the galvanizing prior to welding. If they aren't following proper safety precautions, they already know it because the welders would be getting sick after short exposure to galvanizing fumes during welding.

Marty

By oldkid

Date 11-18-2002 02:59

Well they are not applying the galvanizing after welding. They are using galvaized pipe and sheet metal to manufacture horse corrals, feeders etc. I will definately check out their safety precautions and equipment.
Thanks
Mark

By dee

Date 11-18-2002 04:11

Mark,
I have heard some conflicting accounts of the level of toxicity of Zn.
Of course inhaling the fumes makes you sick, but it's not the same thing going on as many of the heavy metals. ONe account actually made a point about Zn being a necesary mineral for health, and is regularly found in vitamins, but then again so is selenium, which also demonstrates some toxic effects. Point is, it's nothing like cadmium, lead or chromium.

I am still learning about it.

As poisons go it's apparently pretty benign. It causes fever, chills, nausea and vomiting, muscle aches and weakness with recovery in 24-48 hours. Zinc chloride may cause pulmonary edema, cyanosis and dyspnea (somewhat more serious) with a fatality rate of 10-40% (I guess the chlorine helps its toxicity)

You may also note there is something going on with nickel and carcinogenisis (cancer) of the respiratory tract, and vanadium, cobalt and other common alloying elements also tend to be rather toxic if not carcinogenic as well.

Keep out of all the fumes; presuming them to all be toxic is the only safe course of action. We rarely really know what were dealing with, but frankly, I personally am least concerned with zinc. Many metals accumulate in the body, but I do not believe that is true with Zn.

Regards,
d

By jwright650 (*****)

Date 11-18-2002 13:08

Keep in mind that these fumes accumulate in your system too. Over time small traces each day can add up.
I use a "3M" model #8514 N95 Particulate Disposable respirator, these do well if you don't stick your head in the plume too much. They are good for about 8hrs of welding and then you'll have to throw them away because the filter will clog and you'll find it hard to breathe. They work on stainless steel, aluminum, galvanized steel, etc.
Hope this helps you from becoming sick from the fumes,
John Wright

By dee

Date 11-18-2002 21:16

j
According to Dr. Rbt H. Dreisbach,chronic poisoning does not occur with zinc fume inhallation, and recovery occurs in 24-48 hours. There have been no known deaths attributable to it in recent history.
Be assured the human body has the mechanism by which to [more or less rapidly] metabolize Zn. You may be surprised to learn it can even clear itself of Pb; at a half-life in bone over 32 years and 7 in kidneys it is indeed a slow process.

One of the most toxic of metal fumes is cadmium, which seems to show toxic effects upon any cell or organism tested.
Chromium causes ulcerations, bleeding, and many other problems.

While it is allways correct to err on the side of prudent caution, as I myself may have said the effects of ZN may be cumulative, I doubt now this is the case. It would be as irresponsible for me to cause a false sense of security as a false panic in the case of Zn. Metal fumes is bad stuff, but on the other hand it isn't plutonium.
Cumulative effects of metal poisoning is, however, a rule of thumb and it was good to have seen that pointed out.

By jwright650 (*****)

Date 11-19-2002 16:29

Galanized fumes,
It might not be fatal to breathe, but it sure is uncomfortable when you get enough of it to make you sick. I never enjoyed the experience, so I make our guys use the disposable respirators. Actually they ask for them, I don't "make" them wear it. Even if it only makes you think you are being safer, the guys at least think you are trying to look out for their well being. Morale is important in a shop, the days go by alot better with good morale.
I didn't mean to create panic in the welding world, but I'm sure I'm not the only person who has been terribly ill from those dreaded green and yellow fumes.
It looks like galvanized jobs come in spurts. We'll go several months without a single piece of steel needing to be hot dipped. Then we'll get several jobs at once that will last months, all galvanized. After several days of welding on this stuff, you'll feel the effects.
I know what you're thinking, "Do you want some cheese to go with that whine?"
Take care,
John Wright

By dee

Date 11-19-2002 22:30

John
Took me a minute to get the "cheese" joke...LOL... AHHHH, the power of cheese!

I'm not minimizing the importance of safe practice with the fumes, but rather I'm apparently having a hard time forming a context for others to understand my point of view. I try to fight that problem all the time.

One point poorly made is that it's probably a good idea to recognize the various symptoms of the metal poisonings we might encounter, so they might be caught at as early a stage as possible.

Another point I did amazingly poorly with is my opinion that if welders are getting sick with fumes from Zn, they are not working safely. That established as a required condition, I don't feel any particular precautions are required for galvanized. (Thats NOT to say welding anything, including Zn, should be done without regard to the fumes- exactly the opposite is true)

In any event, a grass-roots effort to start a safety section here in the BBS seems to be meeting some resistance from somewhere. If it might serve to save a life or avert a disaster any objections are, IMHO, irrelevant. Perhaps an email to the administrator would be constructive if our opinions converge on this point; safety is allways a good thing to discuss.

Regards,
d

By jwright650 (*****)

Date 11-20-2002 12:40

Dee,
Hey,I hear ya man! See, another hat I get to wear is the Safety Manager's hat here at our company(along with the enviromental compliance manager's hat) all that added over and beyond the QC/QA manager's duties they have entrusted to me as well. Yeah, I'm busy.
Anyway, a Safety Topic section would indeed be benificial to me as well. I always need fresh ideas, pros and cons, about safety subjects. Welding does involve safety issues of all sorts. AWS even publishes an ANSI standard Z49.1:1999 that addresses Safety in Welding, Cutting, and Allied Processes.
I enjoy reading over the topics on this BBS and the Safety Topic Section would be helpful and it would help separate safety from all the other welding topics. This would serve to "clean up" or organize the topics in a more orderly fashion.
What do ya think,
John Wright

By magodley (**)

Date 11-20-2002 13:26

I too would like to see a safety issue spot. In regard to the galvanized issue, if you investigatge far enough you might find other componets like pb in the coatings. AWS has published many documents on fumes and their affect on people. My advice is go ahead and take all the precautions.
Andy

By wfs4998 (*)

Date 11-20-2002 14:57

Why can't you use a fan nearby to blow the bad fumes away from you while welding galvanized metal?

By jwright650 (*****)

Date 11-20-2002 15:41

Fan works OK for SMAW, but FCAW and GMAW don't like breezes.

By TimGary (****)

Date 11-20-2002 16:28

I've unfortunately had to do alot of work on galvanized material including torch cutting, welding, and galva-bar coating.
Personally, I despise having to work with the wretched stuff. The zinc is always a pain to remove if your welding and you can never seem to remove enough to avoid burning some. It is also a pain to burn through with a torch as it causes a sloppy cut and a ventilation overwhelming amount of smoke.
The first couple of times I worked with it, I did not have the proper ventilation and didn't know better. The result was SEVERE headache and nausea that left me incapacitated for hours. After the old-timers I was working around had their laughs and thought that I had been "initiated" enough, they told me to make sure I had the wind to my back when working with zinc, don't breath the fumes any more than you have to, and to drink plenty of Milk as it is the "cure" for zinc poisoning.
Knowing these tips prevented me from becoming seriously ill again, but I cannot remeber a single time that I worked with Zinc that I did'nt get at least a little bit sick, no matter how good the ventilation. Maybe I'm more prone to the adverse effects than other people, or maybe it's in my head, but I would rather take a beating than to work with Zinc.
As for welding on galvanized piping all day, every day.... not a chance.
Anyway, that's just my opinion...
Tim

By jwright650 (*****)

Date 11-20-2002 19:27

Tim,
I hear what you're saying, it's not fun to work with. Like I said in an earlier post, the effects are greatly minimized with the disposable respirator I described before, and it fits under all the Jackson welding shields we've used. I do think that some people are more affected than others. Trying to weld through the stuff without removing it makes for ugly welds that usually need more attention before I'll let it go onto the truck headed for the jobsite. I like for my guys to grind off as much as possible around the joint to be welded, and then touch it up with cold galvanizing compound after it has cooled.
John Wright

By dee

Date 11-20-2002 22:24

John,
In an old archive somewhere I believe it was Mr Jooste or perhaps Mr Crisi who stressed that grinding to remove Zn is inappropriate for critical welds. Apparently the Zn can best be removed by [burning] it off with a torch flame, otherwise, even the amount of Zn dragged in on the abrasive wheel tends to cause cracking. I dunno.

In any event it rather defeats the principle of avoiding burning the stuff to avoid the fumes.

Has anyone else any experience with just how critical it is to avoid contamination with Zn?

d

By jwright650 (*****)

Date 11-21-2002 12:16

d,
Yep,I think I remember the post you are talking about. I think he's got a good point about the critical welds. Just like when welding stainless, you will need a stainless wire brush, that has not been contaminated with other materials, to clean your joint before welding.
John Wright