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If you are a professional welder or someone who likes to DIY, you should know about welding electrodes – also known as rods.
So what exactly are welding rods?
Welding rods are flux-coated metal wires that are melted and work as a catalyst to join pieces of metal together. Welding rods are also sometimes referred to as electrodes, and they are considered “consumables” in that they are used up during a fusion welding process.
The adhesive power of the rod wire is extremely strong and reliable since it is literally metal that disintegrates or melts to form a bond between metals.
There are various categories and types of welding electrodes. This welding rod guide will help you get detailed knowledge about the kinds of welding electrodes along with their pros and cons. And thus you can choose the best one for your welding applications.
History: Who invented welding rods?
Nikolay Gavrilovich Slavyanov, a Russian inventor introduced arc welding with consumable metal electrodes.
He started practical use of arc welding for a metal for the first time in the history of the world, in November, 1888. Before this, only carbon electrodes invented by Nikolay Benardos had been used.
In connection with this process, Nikolay Gavrilovich Slavyanov chose to call his method “Electric Casting of Metals” instead of welding.
He received a gold medal for this innovative contribution, at the World Electro Technical Exhibition ‘1893 in Chicago.
How do welding rods work?
While welding on a specific joint of metal, the current comes from the machine to the electrode holder, to the grounded area where welding is happening. And it results in heating and melting the electrode to create a metal bead.
The bead then solidifies as the temperature cools, holding the metal joints together. In other words, welding is a way of bonding pieces of metal. In fusion welding, the melted piece of metal (or “bead”) is the electrode (aka “rod” since its a long wire or rod shape).
There are of course, other ways to bond metal such as riveting, soldering, and brazing. But welding has become most popular because of its strength, versatility, and efficiency.
What are the components of a welding rod?
A welding electrode is composed of two parts. One is the metal core wire, another is flux coating.
The chemical composition of the metal can vary. It might be Bronze, Cast Iron, Aluminium, stainless, mild or high tensile steel.
The flux that coats is made of Cellulose, Hydrogen, Sodium, Titanium, Potassium and Iron powder. So the two main ingredients of a welding rod are Iron and Cellulose.
How are welding rods made?
The production of welding electrodes happens in two major steps-
- Formation of metal core wire
- And Flux coating it on the outside.
1. Forming the metal core wire
The metals used for the core can be cast iron, copper, aluminum, brass or mild steel. Let’s see the process in detail.
Firstly, a bundle of wire is pulled through drawing dies to reduce the cross-section area. These are then drawn in the metal forming machines to get strengthened and cut according to specified requirements.
2. Flux coating the wire
Flux is then coated on the wire using an extrusion press.
The flux goes under pressure through a cylindrical press and the wire enters into it from a wire magazine. A nozzle or die box mechanism incorporated in the extrusion press helps the wire get well coated with the flux.
Then the eccentricity tester checks if the formation of the rods is satisfactory. The coat is used for even current flow through the core.
After testing, proper ones are placed in an oven to bake to reduce the moisture.
Finally, the type of electrode is printed on its body. Rejected ones can be processed again.
Welding rod coating materials
The flux is made up of Cellulose, Feldspar, Powered Iron, Hydrogen, Mica, Titanium Dioxide, and Low Carbon Ferro Manganese as dry ingredients.
After proper weighting, they’re entered into a mixer to make a homogenous mixture. Potassium, Sodium, Potassium silicate are used for binding the dry mixture.
Then this is formed into briquettes with the help of hydraulic press.
Types of welding rods and specifications
Welding electrodes are available in various specifications and sizes. Different kinds of work call for different kinds of rods.
Here is a list of various welding rods and their different uses.
6010 Welding Rods
This is typically used in pipelines or to repair pipes. Both AC/DC are okay for this.
This provides deep penetration. It gives good control in handling the arc and also works fine in almost all positions. This rod is ideal for patchwork and repairing. It consists of the coating of high cellulose sodium so it can only be used with DC and current.
6011 Welding Rods
These are made suitable mostly for AC. Industries and steam pipe line constructions use these electrodes.
It needs more manipulation and is tough to operate. This can withstand 60thousands lbs. of pressure. It’s coating level of cellulose potassium is high, so it can operate using AC as well as DC currents.
One of its drawbacks is it produces slags that are harder to remove than others.
6013 Welding Rods
This is specially made for farmers. It doesn’t dig through paint or rust. Also provides smooth and clean welding.
The 6013 rods can withstand 60thousands lbs. of stress/square inch. Its the third digit, 1 indicates that all welding procedures are applicable for it. (Read more about 6011 Vs 6013 Welding Rods).
The last digit 13 says that it comes with a high coating of titanium-potassium. So, it is suitable for almost any type of power supply.
7018 Welding Rods
This electrode can deal with welding structural steel, pipes and to repair the pipeline if damage occurs. It results in strong and smooth welds.
It can withstand 70 thousands lbs. Per cubic square inch. It’s also suitable for all positions of welding. Welders use this one in powerhouses, dams, factories, bridges, nuclear weapons etc.
Since this rod creates a hydrogen-free flux, a moisture-free place is the perfect storage option for this.
7024 Welding Rods
This rod is a perfect choice for flat-horizontal welding, but it is not suitable for vertical welding.
It gives a mild penetration. It’s quite easy to use. Arc length is maintained using thick flux. It also helps drag the rod according to requirements.
How do you store welding rods?
Welding rods have to be stored properly or else they will become useless. And welding rods have to be stored in a dry, preferably hot and less humid place. These instructions are usually always mentioned in the package.
It is a very good idea not to throw away the package or storage box that comes with the rods. Because those boxes and packets are made suitable for the rods. You have to find a new storage option only if they are opened.
Putting them in upright position in a single row minimizes the chance of them knocking each other and causing damage and breakage.
Rod ovens are a good choice to store a large number of welding rods. They keep the temperature consistent and maintain a dry environment for the rods. They can cost anywhere between $100 to $10,000. However, this is certainly not necessary.
It is best to read the instructions that come from the manufacturer of the rods. That’s you are using because every kind of rods has specific storage requirements.
Can welding rods be recycled?
Yes, these can be recycled. The leftover rods can be recycled, repurposed or even upcycled. Metals are generally not harmful for the environment. So, welding electrodes are safe too.
The rejected or half-used ones are also processed again to make good rods. So, there’s minimum waste and almost all of them can be used.
Answering some question about welding rods (FAQs)
Q. Which is the best welding rod to start with?
Ans: 6011 is easy to use so it’s beginner-friendly. Mild steel or aluminum, it can weld pretty much anything.
Q. Can I use welding rods to repair pot metals?
Ans: Yes, some welding rods can be used to repair pot metals.
Q. Do you need a rod oven for welding?
Ans: Professionals welders or hobbyists who want high-standard output can get one. But if you are just starting out, don’t stress buying a rod oven right away.
Q. Do welding rods go bad?
Ans: Yes, welding rods can go bad. It depends on its storage condition and sensitivity to moisture.
Q. Which welding rods go bad the fastest?
Ans: The answer is 7018, due to its extreme sensitivity to moisture.
Q. Do they have a shelf life?
Ans: Yes they do. Shelf life primarily depends on the type of rods you’re using and how you store it.
Q. Signs that your welding rod can’t be saved?
Ans: If flux has been softened or has visible powder residue, the rod should be discarded.
Q. How long can a 7018 welding rod be out of the oven?
Ans: A 7018 welding rod can be out of the oven within 3-4 hours after removal from the oven.
Q. Do I have to keep my rods hot if I’m not performing code work?
Ans: Not necessarily. If it is not code work, just decorative style welding, you can focus on keeping it dry only.
Q. How long can you store welding rods?
Ans: This basically depends on how you use and store them. Do handle these rods carefully to expand their shelf life.
This content is written with all the information you need to know about welding and welding rods. Topics discussed here include the types, composition of these rods, also how to choose, store and work with welding electrodes.
Whether for professional purposes or not, this guide should answer most of your questions regarding welding. I hope this welding rod guide was informative enough to make your welding experience easier. However, if you still have further queries, we suggest you go to your nearest welding or hardware shop.