Topic: Welding Galvanized Metal...

[NorCalToy]

I have heard different things about welding on galvanized metal...

so:

What are the dangers (fumes, toxic, etc...)?

What is the strength compared to normal tubing?

Does it hold paint if rattlecanned?

Like i said, i dont know very much about it, i am just wondering because i have heard that you can and cannot weld it. Did a Google search and came up with mixed results.

Thanks for the help

[crawlerdan]

i am a former professional welder-there are myths and sayings but heres the facts from the oregon structural enineers union-in my words

yes there are fumes-weld in  a well vented, or fan blown area

you can weld structurally if you remove the galvinized coating at least 1/4 inch from the weld surface

if this is done on both surfaces-strength loss is minimal if present at all

and in my opinion, if you have to do it, so be it-but non galvanized is easier

yes it will hold paint if prepped normally-although it will always look like ass IMHO

i used to weld galvy plate to galvy pipe for pile driving type situations, then houses sat on em-so yes it is plent strong- but if you try to weld without removing the coating- it will leave voids, pockets of gas and air, and not pennetrate well, resulting in a poor quality weld


hope that helps

[BLACKDOG]

i am a former professional welder-there are myths and sayings but heres the facts from the oregon structural enineers union-in my words

yes there are fumes-weld in  a well vented, or fan blown area

you can weld structurally if you remove the galvinized coating at least 1/4 inch from the weld surface

if this is done on both surfaces-strength loss is minimal if present at all

and in my opinion, if you have to do it, so be it-but non galvanized is easier

yes it will hold paint if prepped normally-although it will always look like ass IMHO

i used to weld galvy plate to galvy pipe for pile driving type situations, then houses sat on em-so yes it is plent strong- but if you try to weld without removing the coating- it will leave voids, pockets of gas and air, and not pennetrate well, resulting in a poor quality weld


hope that helps

 

And x2 on the ventilation.  If you don't ventilate well, you can get very nauseous, and get some pretty bad headaches.  I'm sure there is long term effects as well, but I don't know exactly what they are. 

My sliders are made outta galvy, work just fine, plenty strong and durable. 

[crawlerdan]

the long term effects are...you end up looking like CrawlerDan 



but seriously, i puked black foam a few times

[abnormaltoy]

x3 on the tips.

Breathing zinc fumes is very bad for your future.

[Trunkz]

zinc fumes can make your future very short, ill have to dig up an article on it, but  a blacksmith i knew died from them

[kneedownnate]

Never welded it, but I've cut way, way, way too much galvanized metal with a torch and can vouch that the fumes are very bad for you.  If you inhale any at all make sure you chug a bunch of milk asap to absorb the toxins.

[4XFlyin]

The more you grind away from the weld area the better. I once got violently ill from the fumes. Barfed very painfully and felt like I was going to die. My body felt like Sh!zt.

[BLACKDOG]

the long term effects are...you end up looking like CrawlerDan 



but seriously, i puked black foam a few times

  no more welding galvy for me

[jimbo74]

activated charcoal is much better than milk

[toyotaman27]

Galvanized metals leave a tar in your lungs which make it hard to breath. This shortness of breath leads to upset stomach and kidney pains. But it is just a coating on the metal that can be ground down and ur just left with raw iron. The metal is as strong as ur weld.

[Stocker]

A contractor who worked for us several years ago had a terrible sounding voice -- hoarse, raspy, a bit muted and sometimes hard to understand.  He said it got that way from welding galvanized culverts.  Ventilate, ventilate, ventilate...


PS    He's dead now, but I don't know if there was any connection...

[BLACKDOG]

activated charcoal is much better than milk

Not for this case.  Activated charcoal coats the stomach, preventing absorbtion, but it also generall induces vomiting.  I don't think this is a situation where vomiting is a good thing to induce.  Seeing as the majority of the toxins wind up in the mouth, nose, sinuses, and airway, causing vomiting will just aggrivate the esophagus, and the mouth.  Personally I don't think the milk would really help either, it would certainly coat the mouth and upper throat though, so it may help to a point.  I know some people swear by it, and others think its bull, I don't have any personal experience to that extent either way.  

[Hyena]

I weld it at work all the time.  grind the off and i always where a resperator.

[yotaboy79]

i avoid it like the plague. it takes way to long to prep verses raw steel and it will make you sick, ive gotten sick from in and for me the milk did make me feel alot better

[NorCalToy [OP]]

cool thanks guys. i was just wondering, i started to read blingn's build thread and had thought you could not weld it, so i posted this up. i also thought it was more than just a coating on the metal...

wouldn't zinc make the metal rust faster? i read somewhere on here about putting a zinc block on the underside of the truck to attract some type of chemical so the rust eats it away before anything else. said it was a technique used on boats.

[jimbo74]

Zinc coatings prevent corrosion of the protected metal by forming a physical barrier, and by acting as a sacrificial anode if this barrier is damaged. When exposed to the atmosphere, zinc reacts with oxygen to form zinc oxide, which further reacts with water molecules in the air to form zinc hydroxide. Finally zinc hydroxide reacts with carbon dioxide in the atmosphere to yield a thin, impermeable, tenacious and quite insoluble dull grey layer of zinc carbonate which adheres extremely well to the underlying zinc, so protecting it from further corrosion, in a way similar to the protection afforded to aluminium and stainless steels by their oxide layers.

[kneedownnate]

wouldn't zinc make the metal rust faster? i read somewhere on here about putting a zinc block on the underside of the truck to attract some type of chemical so the rust eats it away before anything else. said it was a technique used on boats.

  sacrificial anode    It's a softer material that's supposed to degrade instead of your pontoons, hull, transom, drive, outboard or any other metal parts that may be in contact with the water.  It'd be nearly pointless to use on a truck unless you're constantly driving through creeks though 

Here's a link to better describe it  http://en.wikipedia.org/wiki/Sacrificial_anode

[NorCalToy [OP]]

i read it when reading a thread where you had posted about it. thanks for the tech terms kneedown and jim.

so its only really effective if the vehicle is constantly in water?

[MiniSimp]

Copy and paste:

WELDING ON GALVANIZED METALS
One of the most significant health hazards in the welding process is the generation of fumes and gasses. Do you weld on galvanized metals? Zinc is the coating used on galvanized metals, and when you heat the metal, it produces vaporized metal droplets which are called fumes. This is the smoky haze which consists of fine particles of metals or silicates. When you breathe these fumes, they may work deeply into your lungs.


The typical effect of breathing zinc fumes is metal fume fever. One or two hours or more after welding-without proper personal protection-you may experience severe thirst, pain in the legs, shivering, congestion in the head, dryness and tickling of the throat, and a cough. In very bad cases, you may feel severe shivering, a high fever, buzzing in the ears, nausea, vomiting, and even hallucinations and convulsions. Your symptoms will usually last 24 hours.


Some of you may weld for a period of time and find some of the symptoms appeared, then went away. You may actually have built up an immunity that hides the full effects. If you take a break from welding over the weekend or over a holiday, the symptoms will often come back again the next time you weld on galvanized metal. Because of this behavior, metal fume fever is sometimes known as "Monday morning sickness."


Protect yourself, if you weld on galvanized metals, by following these precautions:

In all operations where metal fumes are present, you should work in a well ventilated area. The best way to protect yourself against metal fumes is to use local exhaust ventilation at the source of the smoke. Do not re-circulate the air in the shop.
If good local ventilation is not possible you should wear an approved respirator, which will fit underneath your welding helmet, to protect yourself from fumes. This respirator collects the fume particles and keeps them from entering your lungs. (A paper dust mask is not adequate).
If you find white dust inside your welding shield, you are not properly protecting yourself from the fumes.
After you have finished welding, wash your hands and face thoroughly with soap and water.
Do not eat, drink, or smoke in areas contaminated by welding fumes.
If you think you are experiencing symptoms of metal fume fever, report it to your supervisor. Physicians familiar with this illness say that the best treatment is to drink plenty of water and go to bed and rest.
Finally, did you know that you can "contaminate" your family by bringing home zinc particles on your clothing? Protect both yourself and your family-weld safely.

http://en.wikipedia.org/wiki/Metal_fume_fever

[NorCalToy [OP]]

i didnt even think to check wikipedia. i googled and got yes's and no's as to whether or not it can be done. thanks mini

[toby]

I believe muriatic acid, the stuff you use for swimming pools will remove the galvanized coating. Soak the area you are going to weld until it dissolves. Handy when doing nuts and or bolts if your doing big stuff it will probably be more difficult.

[DTB]

you can weld structurally if you remove the galvinized coating at least 1/4 inch from the weld surface

I would probably do a little more than that (maybe 1/2 inch or more) ....just to be safe

[BLACKDOG]

I would probably do a little more than that (maybe 1/2 inch or more) ....just to be safe

Forgot to mention earlier too, when you're grinding that off, wear a respirator!!  That dust itself is pretty gnarly   

[crawlerdan]

I would probably do a little more than that (maybe 1/2 inch or more) ....just to be safe

jut tellin you what the inspector says