Advise for Galvanized Steel

[artdutra04]

Originally Posted by MrBasse

I always cringe when new people are jumped on for spreading misinformation... but I feel that this is a time for learning as well.

You can weld galvanized steel with no issues as long as you use proper equipment. You do not get zinc poisoning from the fumes. However, you should have adequate ventilation (read as borderline too much ventilation) and proper equipment (i.e. respirator) to avoid zinc oxide irritation which is similar to an allergic reaction that results in what is known as "metal fume fever." It is greatly unpleasant and has symptoms like the common flu. Fever, chills, awful headaches, and other not so fun issues commonly arise. These symptoms will be horribly uncomfortable, but generally clear up in 6-10 hours. If zinc oxide was so bad, we probably wouldn't rub it all over our bodies every summer. Most cases of major problems from welding galvanized steel are generally related to people who develop pneumonia or already have a weak respiratory or immune system, or where a person was so engulfed in fumes that the building was evacuated for visibility issues due to burning coatings of to prep for welding operations.

...

Or... grind off the galvanized coating first before welding. But then it's not galvanized steel anymore.

The reason I stated here to not weld it is because in the decision tree of pursuing things that have negative consequences, taking actions to avoid the situation should ALWAYS come before taking steps to mitigate the problem. Zinc poisoning / metal fume fever are just semantics for the same result - you can easily get sick if you do this action.

Even worse, is that people who may have a cursory knowledge of welding may not realize that they need to do anything different when welding galvanized steel, and won't realize until too late. This is the same reason why I will recommend to everyone to never laser cut polycarbonate, since avoiding dangerous fumes in the first place is better than dealing with the consequences.

Since FRC robots aren't generally subjected to salt bath/sppray tests or acidic or super humid environments, there aren't really any compelling reasons to use galvanized steel over regular steel or aluminum or polycarbonate etc., especially when a light oil coating can keep your regular steel from rusting.

And yes, while zinc oxide itself is safe in most applications (even noted by the FDA as "generally recognized as safe"), it's the fumes that are dangerous. Technically water fits this same description.

Originally Posted by yash101

I will have to agree with that. It scared me when I read, "you will get zinc poisoning by welding galvanized steel" because this is a type of steel. Many times, you will find steel welded, like in cars. I will have to agree with MrBasse that aluminum is much better on FRC robots.
...

There is nothing wrong with welding steel, it's welding galvanized steel that you have to take extra precautions on. Galvanized steel is just any normal steel alloy that is coated in zinc to have better anti-corrosion properties (e.g. not rust).

[jman4747]

Originally Posted by artdutra04

Since FRC robots aren't generally subjected to salt bath/sppray tests or acidic or super humid environments, there aren't really any compelling reasons to use galvanized steel over regular steel or aluminum or polycarbonate etc.,

Except that its free.

Also I assume it would be okay to water jet it?

[Ether]

Originally Posted by artdutra04

And yes, while zinc oxide itself is safe in most applications...

...like multi-vitamins with minerals for example ... check the label.

...it's the fumes that are dangerous. Technically water fits this same description.

Yes, do not inhale superheated steam.

[yash101]

Let's just end this argument about whether zinc fumes are dangerous. Let's just say, zinc oxide can be dangerous, but isn't always, so just make sure to have proper ventilation.

It's never bad to be overcautious, especially when you can be harmed severely, or maybe even killed. That's why we give safety tests to students before they can use tools!

[MrBasse]

Originally Posted by yash101

Let's just end this argument about whether zinc fumes are dangerous. Let's just say, zinc oxide can be dangerous, but isn't always, so just make sure to have proper ventilation. Just a fan blowing outside the building from where you are working should probably suffice, I guess!

It's never bad to be overcautious, especially when you can be harmed severely, or maybe even killed. That's why we give safety tests to students before they can use tools!

Just a fan will get you into dealing with all of the symptoms I listed earlier. To avoid a lot of discomfort you need a dedicated welding ventilation system and most likely a respirator for any residual fumes that get past the ventilation system.

[CENTURION]

Originally Posted by yash101

Let's just end this argument about whether zinc fumes are dangerous. Let's just say, zinc oxide can be dangerous, but isn't always, so just make sure to have proper ventilation. Just a fan blowing outside the building from where you are working should probably suffice, I guess!

It's never bad to be overcautious, especially when you can be harmed severely, or maybe even killed. That's why we give safety tests to students before they can use tools!

(Emphasis mine)

Please, if you don't actually know what you're talking about, don't offer safety advice on the subject.

I'm a professional machinist, so I handle safety concerns regarding our machine shop. I'm not a professional electrician or electrical engineer, so it's not a very good idea for me to give out safety advice about electricity besides "Don't touch it". Misinformation can cause accidents.

For this same reason, people will give out the advice; "Don't weld galvinized steel". Even though, as others have pointed out; it can be done. But it can only be done if you really, really know what you're doing. But "Don't do it" is a pretty good rule if you don't know exactly how to do it.

A fan blowing air out of the room to the outside is pretty much the bare minimum for ventilation. It might cut it if you want to get rid of some paint fumes, but when you're dealing with fumes that are actually dangerous, it's not going to be good enough.

[Alan Anderson]

Originally Posted by yash101

Let's just say, zinc oxide can be dangerous, but isn't always, so just make sure to have proper ventilation. Just a fan blowing outside the building from where you are working should probably suffice, I guess!

Please don't guess when health and safety are involved. You don't yet have the experience and expertise to give such advice...

...especially when you can be harmed severely, or maybe even killed. That's why we give safety tests to students before they can use tools!

Have you had any training involving the welding of galvanized steel? If not, I urge you to hold your tongue when you get the urge to answer safety-related questions about it. But please keep asking questions!

[edit]I didn't see Evan's note above when I wrote my reply, and I apologize for the redundant message. I didn't delete it, because I think my final sentence is important.[/edit]

[FrankJ]

Here is a fact sheet from the the American Welding Society on metal fume fever. Google is you friend.

[JamesCH95]

As a welder I prefer to TIG-braze galvanized steel with silicon-bronze filler material. I find it results in a strong weld joint and greatly reduces the amount of noxious fumes emitted by the joining process due to the low heat input of brazing and the fact that the base steel isn't actually melted. Several critical parts on our 2013 climbing mechanism were TIG-brazed with silicon-bronze filler.

Others have done a great job of addressing the safety concerns.