Dive knives are not maintenance-free scuba diving accessories. Even a dive knife made of the strongest material needs thorough cleaning after every few dives to stay sharp and free from rust.
Cleaning your dive knife should be part of your routine at the end of a day of diving. Not cleaning your dive knife after every use in the ocean gives the buildup of sand and salt on the knife the chance to cause damage.
Since a scuba dive knife is usually tucked away into a sheath or folded up, you might not notice the rust building up until it is time for your next dive. By this time, you are already too late and will have to do a much longer cleaning of the dive knife to give it back its shine.
How to Maintain your Dive Knife
Carrying a dive knife is a safety precaution for divers, as long as you store a dive knife safely during your dive, and you don’t want your safety precaution to fail while you are underwater because of poor maintenance.
Perhaps for safety reasons, or due to your diving conditions you know you really need a dive knife, now scroll down for the best ways to keep your dive knife sharp and rust-free. And in case there is rust on your dive knife, below are tips on how to remove rust from a dive knife.
Regular Cleaning of a Dive Knife
These next few steps are for basic cleaning tips for your dive knife. These steps are recommended for you on how you should clean your dive knife after each dive.
- Remove the sheath or fold open the dive knife.
- Rinse the dive knife (and the sheath if it is a fixed edge dive knife) in freshwater.
- Let it soak in freshwater for a while so that all parts are covered.
- Carefully dry all parts of the dive knife with a thick but soft cloth. Make sure that there is no moisture left in crevices.
- Apply a layer of wax or silicone that keeps out water.
How to Remove Rust from a Dive Knife
Fortunately, rust can be removed from a dive knife. The cleaning process takes several hours and needs to be done carefully and thoroughly but it is possible.
This is what you can do when there is already rust on the dive knife. Don’t wash the dive knife as the moisture won’t remove the rust anyway.
- Remove any debris and dirt with a regular liquid cleaner and thick cloth.
- Drench another clean cloth in a specific rust-removing cleaner, kerosene or WD-40.
- Wrap this cloth around the dive knife and let it soak through for about 5 hours.
- Now the rust should be loose enough that you can rub it off. Remove the solution and rub away the rust with a steel wool sponge or the special cloth that comes with rust-removing cleaners.
- Once all the rust is removed, clean the dive knife with another clean soft but thick cloth. This is to remove any leftover moisture or grease.
- Repeat steps 1 – 5 if there is still rust on the dive knife. Repeat until the dive knife is completely clean.
Despite being called stainless steel, this material actually rusts easier than titanium dive knives. If you have a stainless steel dive knife then you need to be more thorough with the routine cleaning.
Dive knives made with titanium don’t rust as easily which is why they are easier to keep sharp and rust-free. However, don’t skip the routine cleaning because eventually the titanium can get damaged, as well.
When to Sharpen a Dive Knife
One difference in how to sharpen a dive knife depends on whether it is a sharp edge or a serrated edge. However, since most dive knives have two kinds of edges, this does not apply to many models.
How to sharpen a dive knife mainly depends on the type of material it is made of. Stainless steel dive knives are easier to sharpen than titanium dive knives.
There are several knife sharpening tools on the market with several models that are also suitable for dive knives. The best ones for a dive knife use sharpening rods which make it easier to sharpen the serrated edge.
You can also run the dive knife through a simple electric knife sharpener. This won’t damage the sharp edge nor the serrated edge. If you have a titanium dive knife, check whether it is a complete titanium alloy or only a titanium coating. Dive knives with only a titanium coating can actually lose the titanium layer so be careful when sharpening.