For boat owners around the globe, Deep Blue Yacht Supply is your trusted source for the best zinc anodes in the marine industry. We are committed to providing the best zinc anodes, at the lowest prices, with superior customer service.

Zimar Zinc Anodes set the standard when it comes to cathodic protection. Zimar Zinc Anodes meet all standards set forth by Mil-Spec A-18001K, Mil-Spec A-18001A, and Mil-Spec A-18001. Zimar Zincs are individually hand poured to assure the highest possible zinc concentration and lowest amount of porosity.

Trust Deep Blue Yacht Supply to help equip your boat with the best possible zinc anodes. Deep Blue Yacht Supply is able to provide the ultimate sales and service experience, when it comes to selecting the best zinc anodes to protect your investment against corrosion. Deep Blue Yacht Supply has a huge inventory of the best Shaft Zincs, Plate Zincs, Rudder Zincs, Nut Zincs, etc.

Seawater is inherently corrosive and this is even more pronounced in the case of components that are made of two different metals. Any time two metals are in contact in seawater they will form a battery and one of the two metals will give up its electrons to create the current that flows between the two metals. This process is known as galvanic corrosion and unless you want your boat to begin failing you it is important that we halt this process before it begins. This is done by using a third metal which will more readily give up electrons to create a current. In boating, zinc is most commonly used and the zinc pieces are called zinc anodes, or more commonly just zincs.

Zinc anodes are used on boats anywhere two metals come in contact with each other and are thus subject to galvanic corrosion. This is most common with a stainless steel shaft and aluminum propeller, but there are many other places where two different metals come in contact on a boat. Without the protection of a zinc anode you risk corrosion seriously affecting your parts and components.

Some people think that as long as zinc is present it will protect the other metals on their boats, however they soon learn to their chagrin that this is not true. You can not protect your metal components by simply hanging a piece of zinc over the side of the boat, the zinc anodes must be in contact with the metals they are protecting. This isn't a big deal though as boat and engine manufactures have designed parts to allow for the inclusion of zinc anodes, from the zinc collar that goes around your shaft to the zinc hull plates that are used to protect bronze through-hull fittings to the various zincs in an engine there is typically a protection wherever there are two metals with the possibility of galvanic corrosion occurring.

Now that you know about the importance of zinc anodes it should also be stressed that these anodes do not last forever. Because they are sacrificing themselves to protect your more important metal parts they corrode themselves and are slowly worn down. As a rule of thumb the zinc anodes should be roughly 1% of the surface area they are protecting and should only need to be replaced annually. To be safe though you should inspect all your metal parts regularly for signs of corrosion and if any is present replace your zincs immediately. Typically zincs are replaced when they are only half consumed. Once they go beyond this they are significantly less effective and you risk damage to the parts you are trying to protect.

The good news is that zinc anodes are not expensive, many cost just several dollars and even larger hull plates can be had for under $30 in many cases. When installing zinc anodes be sure that they are in contact with the metal being protected, do not paint the surface of the zinc and make sure that both the zinc and other metal surface are bare and bright before installing the anode. In the case of your engine you should refer to the owner’s manual to be sure you know the location of all the zincs, some can be difficult to locate if you aren't aware that they are there.

It is good that there is a way to protect your metal parts, but the protection only lasts as long as you keep your zinc anodes bigger than half depleted. Make it a habit to check for corrosion regularly and replace those zincs when they are half depleted.

About Zinc Anodes

Without a doubt, some parts of a watercraft are much better known than others are.  While even non-boaters have probably heard of propellers, outboard motors, and rudders, some boating enthusiasts may not have heard of zinc anodes, also known as boat zincs.

What are Boat Zincs?

Boat zincs come in a variety of shapes such as plates, disks, and cylinders, but what they all have in common is a surface area that allows the metal of zinc to help prevent galvanic corrosion on other parts of your boat. Zinc anodes work by giving up their own electrons so that other metals located nearby will not give up theirs.  Boat zincs in this way can help to prevent corrosion of boat parts such as stern drives, steel shafts, rudders, fittings, and above all, propellers themselves.

Boat zincs such as plate zincs, nut zincs, and shaft zincs are also called “sacrificial anodes” or “sacrificial zincs” because they will corrode as they keep other metals from doing the same.  Boating enthusiasts need to keep careful track of their zincs because once they have decayed a great deal, they will no longer be able to prevent corrosion effectively.  At this point, boat zincs need to be replaced so that propellers and other metal pieces have continued protection.

Boaters should also be diligent to check for corrosion on their propellers because such corrosion can mean that more zinc surface area is needed to protect it fully.  As a general rule of thumb, boaters need to have 1/100^th as much zinc surface area as the area being protected, but some situations will require additional zinc anodes.

Zinc Anodes Protects Metals from Corrosion

One unfortunate side effect of immersing metals in seawater is corrosion. A specific type of decay known as galvanic corrosion can happen when two kinds of metal are connected and then exposed to salt water.  In layman’s terms, this causes the metals to behave in a battery-like fashion; current will begin to flow between them as electrons from the atoms of one of the metals are converted into metal ions and lost into the seawater.  Galvanic corrosion usually proceeds at a rapid pace and destroys the metals involved.

This is obviously a large problem for boaters.  Propellers are frequently mounted on shafts made of stainless steel, but those same propellers are themselves made of other metals such as aluminum or alloys such as bronze.

Avoiding Galvanic Corrosion: The Role of Anodes

In order to avoid forming a battery circuit, designers of boats and motors have long used the technique of the anode.  This involves providing a third type of metal such as zinc, which is placed in electrical contact with the other two metals involved.  Designed to be “sacrificed,” this third metal has inherent qualities that cause it to readily lose electrons.  Since nature takes the path of least resistance, the zinc anodes will decay and eventually be replaced so that shafts and propellers can remain pristine.

Boat zincs can also help to protect other watercraft elements such as rudders and hull plates.  These zincs take a variety of forms including round plates, rectangular plates, and cylinders designed to encircle a propeller shaft.