If “Can you weld magnets?” is a question you have been asking yourself and you have not been able to obtain an answer, you have come to the right place. I had the same question, so I did some research.
So is it possible to weld magnets together? Yes, it is possible to weld magnets. However, can you do it, or should you try doing it at home are the two other aspects to consider. Let me spoil it for you, the answer to these questions is no.
Why can’t I weld magnets at home?
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A one-word answer will not suffice in the world of welding as there are numerous terms, conditions and additional factors to be considered when it comes to welding magnets.
Magnets are complex objects and there are several technicalities that must be considered when welding them. For example, minimizing or eliminating magnetic fields during the welding process which are difficult and dangerous challenges. Even for those who know their way around a welder.
Even upon the removal of an external magnetic field, there exists a probability of residual magnetism whereby magnetization remains in ferromagnetic material.
The welding temperature and techniques must be carefully controlled according to the magnet’s thermal conductivity, reactivity as well as propensity to maintain its remnant magnetization throughout the process of welding.
The most feasible way to weld magnets is via arc welding processes wherein gas tungsten arc welding (GTAW), submerged arc welding (SAW), and shielded metal arc welding (SMAW) are utilized with the latter being the most sought out method.
However, ‘magnetic arc blow’ is an obstacle that may occur during such processes if the magnet is not sufficiently demagnetized and the conditions are not strictly controlled.
We’ll discuss further the significance of removing external magnetic fields and diminishing the remanence and tips on ensuring a magnet is suitable to be incorporated in the welding process.
The Importance of Demagnetization Before Welding
Magnetism is caused when the atoms which constitute a magnet align between its two poles. In the event that a magnet is exposed to high levels of heat beyond a point referred to as the ‘Curie temperature’, the motion of the atoms is misaligned and the magnet begins to lose its magnetic fields. This is a critical process when magnet welding is concerned as, if not executed, can cause magnetic arc blow.
Magnetic arc blow is a phenomenon that is caused when there is an imbalance in the conditions of the magnetic field surrounding the arc. This imbalance may occur due to various reasons. The most common ones being the arc forming at varying distances from the joint and workpiece connection or changes in the direction of the current flow to, through, and from the arc.
Magnetic arc blow may result in welding defects such as porosity, lack of fusion, etc. In extreme cases, depending upon the type of magnet, it might even explode. It is recommended for the degree of magnetism to be within 10 Gauss, 20 Gauss, and 40 Gauss for GTAW, SMAW and SAW. As magnetic arc blow may be caused by residual magnetism itself, it is essential for external magnetic fields to be removed before commencing the welding procedure.
Tips on Magnet Welding
First and foremost, it is important to research the type of magnet you intend to weld and its respective properties in order to ensure a smooth process of demagnetization. Different types of magnets, such as neodymium iron boron, samarium cobalt, alnico, and ferrite magnets, react to heat differently in different ranges.
Once the magnet and its melting properties are identified, the magnet needs to be heated above its Curie temperature and then cooled in a zero field.
AC welding is the recommended method for magnet welding as it has the capacity to facilitate higher temperatures of welding. As you might know, AC can support higher degrees of magnetism, which better combats arc blows, as compared to DC welding.
A commonly used method to ensure minimized magnetism is by wrapping cables around the object and connect the cables to an AC welder tuned to the highest amperage available to detect any possible arc and break the arc with scrap before tuning the welder by a range of 15 amps. Repeat this process until the lowest amperage is attained. Upon the completion of the process, the remnant magnetization, and subsequently the probability of arc blow, should be minimized and possibly eliminated.
Using an AC yoke to detect and measure the presence of magnetic particles at this point is highly beneficial and is, in fact, ideal equipment in this process. Once the conditions suitable for welding a magnet have been attained, the process may continue as is standard procedure for the method of welding assumed. Always pay keen attention to the weld puddle and if there is any sign of interference, search for the cause immediately.
I know, pretty complicated, right? At first, I thought I would try welding magnets, but after researching the whole process, I decided not to. There are just too many variables that can go wrong, and to me, it seems a bit like a waste of time.
Does heat ruin magnets?
Now, once we have talked about welding magnets, let’s cover other questions you might have related to the topic. I know I did get carried away with the linguistics in previous paragraphs, so let’s make things a bit easier to understand from this point on.
So does heat ruin magnets? In the long run, the heat does affect the magnets negatively. Heat causes the particles (or atoms) to move faster inside the magnet. This, in turn, disturbs the magnetic domains and weakens them.
In the long run, exposure to high heat will weaken the magnet bit by bit, until it demagnetizes completely. Keeping the magnet in extreme cold, however, can help to turn this process around. Perhaps even recover it to its original strength. It only applies if the damage done by heat is not too significant.
Magnets as a tool
For those of you who have not noticed, magnets are used everywhere, from screwdrivers to speakers, hard drives, and even in welding. (You might have heard about magnetic holders).
Magnetism in general is even used in cars (valves and solenoids), as well as relays and power drills. Magnets can even be used to generate electricity.
What are welding magnets used for?
Magnetic holders are used as an extra hand for a welder to help align, tack, and weld structures together. As I have done a fair amount of welding, I would say they are an irreplaceable piece of equipment. Of course, there are numerous welding clamps to help as well, but using magnets is in some cases inevitable.
How to use them
Those in the picture are regular arrow magnets that can be used in 45 and 90-degree angles. Maybe 135 is possible, I have not tried it yet, they are too big and bulky.
Anyway, the whole process is pretty straightforward. They are designed to act as a placeholder for two or more pieces of metal. You just place them where you need them. Once they are attached to your base metal, you can drag and move them around until you get the metal aligned exactly how you need it to be. It takes a minute to understand, but you’ll get a hang of it in no time.
You can see the tips of contact points are not at a 90-degree angle. It is important because it helps to prevent any debris from getting on the way, welding beads as well as keep the joints from being magnetized.
Once you have tacked together your frame, or whatever you are working on, just remove the magnets and complete the welds.
The whole process is a bit easier with magnet placeholders that have a switch that enables you to turn it off and on basically. It also makes the process of cleaning the magnets way easier since when you turn it off, the metal particles simply fall off.
How to clean welding magnets?
There is a number of ways you can clean your magnets once they are covered with iron particles. The first and the easiest would be to buy magnets with a switch.
If you are not smart enough like me, the best solution would be to use compressed air and blow it off. Wear safety classes tough as well as respirator while doing it.
If you do not have an adequate air compressor, from what I’ve learned, the next best option is to simply use a dry paper towel or a brush to knock iron dust off.
Another problem that occurs after cleaning them, is the fact that they tend to get iron dust all over them again. For that, I’ve seen people placing the magnets inside a plastic zip bag. That way the dust will stay on the bag as opposed to the magnet until you take them out. Helps to save time and nerves.
Why you should not weld magnetized surfaces?
As we discussed earlier, heat will ruin the magnetism so if you need to weld something that is magnetized, and you need it to be so after welding, kiss it goodbye.
Another thing when welding magnetized surfaces often, if not always leads to arc blow. It can be quite dangerous and it also ruins your weld. It is important to know that welding would only work in this scenario if you do not care about the thing being magnetized afterward, and only if it is slightly magnetized in the first place. If the base metal is too magnetic, you can’t run a bead on that.
To combat arc blow if you need to do some repairs on magnetized surfaces for whatever reason, your best bet would be to use a stick welder on AC. I know that’s the way it’s usually done when necessary.
Can you clue a magnet back together?
The answer to that question based on my knowledge would be no. Usually, what happens when a magnet breaks, you’ll get two separate magnets that repel each other at the breaking point. That’s because the polarity of the magnet adjusts as it breaks.
See, the magnets always have two polarities. North and south – once you break it, there will be 1 piece: north on one side, the broken side would be south. Same with the other – north on one side and south on the broken side. So to clue them back together to their original form, you would have to connect the south with the south. As physics dictate, opposite poles attract and the same poles repel.
Final thoughts
The art of welding magnets is a challenging skill to master but, as with any other matter of competence, it is attainable with the right tools and practice. Nevertheless, magnet welding is not recommended for those who are beginners in the field of welding to attempt on their own. It is highly advisable that one experiments with it using small-scale magnets in the presence of an experienced welder.
If attempting to weld larger objects with magnetic properties, it is advisable to invest in specialized equipment to ensure that the capacity is maintained and welding defects are minimal.
As magnet welding is a niche area in the field, it is vital to thoroughly research the type of magnet to be welded, its properties, the manners of ensuring the prevention of magnetic arc blow, and its compatibility with the method of welding. Other materials possibly integrated as the reactions of a particular magnet type may not be applicable to all.
Always ensure that your magnet is demagnetized appropriately according to its components and always gradually test its propensity to create an arc blow before starting your welding process.
Due to magnet welding being a field that is not as widely pursued as other areas and consequently not having as much coverage as others, do provide inputs of your experience welding magnets by shooting us an email.
