What is the Right Size Magnet for Magnet Fishing?

You could technically use any sized magnet for magnet fishing, but if it isn't the right pull strength the only thing you will be collecting is hooks and maybe a coin or two.

Items underwater may be submerged just below the surface making it easy to pick up, but other parts can be deeper in the sediment and muck. If the items are in thick mud you will need an even stronger magnet force to pull it out. However, if the magnet is too strong you run the risk of not being able to pull it back-out.

The right size magnet for magnet fishing will depend on the user. A 350 Lb magnet is a great place to start, not too weak and not too strong. If you find you need a stronger magnet, be careful. The stronger you go the more risk there is of getting it stuck.

In this article, we will go over what is the right size magnet for magnet fishing, as well as answer some other questions that may come up when searching for the right magnet.

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Magnet strength

You can’t just use a typical refrigerator magnet for magnet fishing. The pull strength just isn’t there and it won’t hold onto objects as you would like them to. You need a magnet that’s called a neodymium magnet. And they come in different strengths.

What is the right size magnet for magnet fishing? The best universal strength is the one meant for holding 350 Lbs. Anything stronger can present problems if it clings to something too heavy to pull up, or sticks to the bottom of a bridge. There are alternative shapes of magnets that might actually prevent this such as the cone shape.

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Types of Magnets

Neodymium magnets are produced by a company called Brute Magnetics. They now create special magnets that are especially helpful for magnet fishing for different types of fishing methods. Here is what they include to be more effective.

Flat ring magnet

This is a basic hockey puck-sized magnet that has a top-mounted loop. This is ideal for bobbing in slow-moving water and off piers and docks. Their smallest magnets start with a 300 Lbs model and move up to 2100 Lbs. These run for normally under 20 dollars apiece, but you might find another neodymium version that’s cheaper on Amazon.

Cone-shaped magnet

This is the same magnet that's inserted into a metal cone so it can be dragged easier. The cone shape helps keep your magnet from getting snagged on rocks or debris. They now offer a bright yellow plastic slipcover model so you can see in clear or shallow water where your magnet is. These magnets allow a starting 375 Lbs pull strength. The plastic cone attachment is optional but sold as a complete kit it starts at 25-30 dollars.

Dual-sided magnet

There are universal magnets that are ideal for dragging. No matter what side it lands on the downward-facing side will make contact with something metal soon enough. The weakest that is offered is 550 Lbs. and is divided into two parts. Each side of the magnet will pull 275 Lbs for both sides and can start at 44 dollars apiece.

Check out my review of the top 10 fishing magnet kits.

Interference gunk

Your magnet will go through water that is covered in mud and muck at the bottom. This stinky substance will have all sorts of interference depending on your technique of fishing. You might snag nails, rusty pieces, fish hooks, and even discarded needles!

All covered with that familiar gunk that canals, lakes, and slow-moving bodies of water tend to have. Ocean water will be different since salt prevents this muck from forming so easily. Your technique and magnet strength will determine how easy it is to retrieve the item.

Different Techniques

Bobbing technique

This is what most people are doing on the edge of a bridge, pier, or dock. It's dropping the line and bobbing around until you find something. This usually washes off muck easy enough, though you'll need to clear-off a flat-ring magnet every so often. Little metal pieces that stick will make it nearly impossible to pull-up a larger item that doesn't have enough hold.

Dragging

Using a double-sided puck or a cone-shaped magnet is great for dragging around. But these will get more abuse in being covered with items as they go through dirty water. A cone shape has a disadvantage since the magnet is facing backward instead of directly on the bottom. While it still has plenty of strength to attract metal, it's not going to get caught as often on obstacles. There is a DIY fix that magnet fishers have figured-out to solve this problem.

Add a plastic bottle liner

This is a method that is used only for the flat-ring magnet. Using a standard 2-liter plastic bottle, about half of the bottom portion is cut-off. The pull rope is run through the top pour spout and the magnet is facing downward. You would then use a heat gun on a low setting to shrink the plastic around the flat ring. When this is done correctly, you then have a plastic slipcover that can be pulled along the bottom. This is also a bonus since the plastic is easier to wipe off any kind of muck and little metal debris.

Proper cleaning of your magnet

It’s amazing how so many magnet fishing enthusiasts don’t keep their magnet clean. It will rust if you don’t take care of the metal. Removing tiny pieces that are still stuck are often left clinging to it which promotes rusting. This makes magnet fishing more of a chore when rusty spots form pits on the magnet housing. A good cleaning towel that helps remove metal bits will keep this from happening. Even coating your magnet with a good layer of WD-40 will prevent rusting for several years.

Keeping the ring attached

Every type of neodymium magnet will have a standard ring that attached with a screwed-in bolt. Making the bolt tight enough is not going to last very long because it will start to loosen. It needs to have something that helps lock the bolt onto the threads.

This is why many magnet fishers use Loctite 243 glue. This is the red tube and it's for permanent thread-lock adhesion. No matter how many times your magnet is knocked-around the thread lock won't allow the rounded ring to come loose.

A good-sized spare

You never know when the worst-case scenario happens and your magnet is stick on something it cannot lift. It might be due to the depth of water you're fishing in that you can't retrieve it from. So you'll have to give up and cut your rope and lose the magnet. This can happen when a stronger magnet is used.

A 500 Lbs magnet sounds great but you don't have a winch on hand to pull it free. Your next alternative is to have a decent spare magnet handy. What is the right size magnet for magnet fishing in this case? You should have at least a magnet that is rated for 300 Lbs to do a good job. This way you can continue fishing and perhaps come back later with swim gear if the water is clean enough.

The proper rope knot

A strong magnet will stick to an object wherever the magnetic surface attaches. Finding a toolbox or heavy object like a sunken bicycle will take time to pull out. Your rope needs to be tied to the ring attachment with a knot that won't come loose.

If you use a magnet that is rater for 400 Lbs or more, it can put too much tension on the rope. The best knot that is recommended is a Palomar Knot. It can then be covered in bicycle handlebar tape or electricians tape. The tape helps resist muck getting into the knot so easily.

Checking your rope often when using the dragging technique will let you know if small cuts or tears are forming. This can lead to the rope breaking faster than you expected it to. Depending on the type of rope you choose, a continual inspection of your rope will be in your favor. You are less likely to lose your magnet this way.

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Related article: Best Knot for Magnet Fishing

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Things to consider

Never anticipate that magnet fishing is without risks. The stronger a magnet is rated, the more strength that is needed to pull something out of the water. Your rope can also snap and you can be injured from the rope recoil. You might also fall backward and land on something that leads to back or bodily injury.

More recently in 2018, a Father and Son both perished while magnet fishing in an English canal. There are no details on how they fell into the water, but they both drowned as a result.

It is unclear what kind of magnet they were using, however, its possible their magnet was too strong. Once they got hold of a heavy object they may have been pulled in because of the weight and canal current. Having a partner on hand is always recommended, while a coordinated group is much better. If an object is too heavy to lift with one rope perhaps a second or third will complete the task.

Conclusion

you should now have a better understanding of what the right size magnet for magnet fishing is. Stronger isn’t always better for magnet fishing. So, using a standard 300-350 Lbs neodymium magnet is perfect.

If you take this advice and the other helpful tips, your next adventure will be safer and more productive.