How to Clean Dirty or Moldy Swim Caps

how to clean swim caps

Swim caps are considered essential swim gear for competitive swimmers due to the many benefits they provide, but they are also the most commonly replaced item due to lack of care. Most of the time, a swim cap is torn or punctured by sharp nails, jewellery, or stretched too much. Other times, they are ruined because they are not cleaned properly, resulting in mold growth and irritated skin.

If you are replacing your swim caps every few months, you might be doing something wrong (or your swim caps are very low quality). Assuming you are caring for them properly, swim caps can literally last months and even years. I’m sure it’s annoying having to spend money on a new swim cap every month; wouldn’t you rather learn how to keep it in good shape so that you can use it for much longer?

In this article, we will cover two important topics with regards to swim cap maintenance: 1) how to clean a dirty swim cap, and 2) how to prevent swim caps from getting dirty in the first place. To be fair, the cleaning process for both scenarios are similar, but we will also provide additional tips with regards to how to dry and store your swim cap. Without further ado, let’s dive in.

How to clean a moldy/dirty swim cap

If you notice that your swim cap has little black dots all over it, unfortunately that’s not a polka dot design that you’ve forgotten about; it’s mold. How the heck does a swim cap get moldy?

Bacteria thrives in warm, damp environments, and this eventually leads to mold formation. Unfortunately, after swimming many swimmers simply toss their swim cap (and other swimwear) into a bag while they are still damp. Unless you have a mesh bag that allows air to circulate, the moisture will never evaporate.

This is the perfect condition for mold growth, and if you fail to control this, then mold formation will occur. Naturally, some amount of it is avoidable; after swimming, you’re not literally going to dry your swimwear before you head home. That said, washing it and properly hanging it up to dry should be the first thing you do once you are back home.

If your swim cap already has mold growing on it, here are the steps on how to clean it up.

Use vinegar

Many people rely on using bleach to clean up any tough messes. For cleaning moldy swim caps, that’s going to be a no-go. Bleach is too strong of a chemical and can permanently damage a swim cap which is made from light materials.

Instead, a gentler (but just as effective) approach is to use vinegar. Vinegar can clean on its own, but it can also enhance other cleaning agents. I even use it regularly with detergent in my washing machine and it gets rid of any unpleasant odors. Here’s how to use it to clean your swim cap.

First, take your swim cap outside and brush off as much visible mold as you can using a soft-bristle brush. Next, take it inside and put it in a basin. Pour some vinegar directly on any moldy areas that weren’t brushed off as a spot treatment. Now leave it to air dry to give the vinegar some time to work its magic.

After 30 or so minutes, fill the basin with cool water and vinegar. You don’t need much vinegar, maybe two or three tablespoon’s worth. If you want, you can combine this with laundry detergent; as mentioned, vinegar will act as a booster. Let the swim cap soak in this solution for 15-30 minutes at a minimum, but longer is better.

Furthermore, drain the basin and rinse the cap in clean water. When trying to get the water out, do NOT wring your swim cap. That will damage the material and possibly tear it. Instead, squeeze the swim cap between two towels by pressing the towels together with the swim cap in between; do not do any twisting motions.

Finally, line dry it in a ventilated area out of direct sunlight. Even though swim caps are designed to protect your head from UV rays, that doesn’t mean that it is completely immune to it. Sunlight will degrade the material and drastically reduce its lifespan, so dry it somewhere in the shade.

Do NOT store your swim cap until it is completely dry, otherwise you will just be recreating the same situation that led to the mold growth in the first place.

Dry your swim cap properly

So we touched on this point above, but we want to expand on how you can best dry your swim cap. Believe it or not, drying a swim cap is something many people mess up on, and this can cause wear and tear or lead to mold growth. It sucks because you can put all of this hard work into cleaning your cap and only to have it get undone at the very last step. We want to help you avoid that.

After rinsing your swim cap, it will still be soaking wet. Use the towel trick we mentioned to gently squeeze any water out of the cap. There will still be a few droplets here and there, but at this point you could just line dry it and call it a day.

If you’re a stickler and want to get it all so that there’s absolutely no chance for mold growth, then you can use some baby powder to absorb the last bits of moisture. This also has the side benefit of preventing the cap from sticking to itself which could deform its shape.

What you want to do is apply a generous amount of baby powder to the inside of the swim cap and leave it there for several hours. You can leave it there for 24 hours to get the best results. After the time has elapsed, take a soft-bristled brush and brush out the powder inside. The advantage of this method over line drying is the cap will not stick to itself which helps keep it soft and gives it a longer lifespan.

Store your swim cap properly

After cleaning your swim cap and drying it, we still aren’t quite done, but we are so close to the finish line. The last remaining step is to store it properly. How hard could it be, you might ask? It’s not hard, but some people don’t realize that improperly storing their gear can also decrease their gears’ lifespan.

Once again, just like how we told you to line dry your swim cap out of direct sunlight, do not make the mistake of storing it anywhere that the sunlight can reach. Your best bet is to put it in your bag, because leaving it out somewhere can potentially expose it to sunlight as it completes its daily rotation.

As for how to actually store the cap, there is a method for that too: put the cap on its crown. Placing the swim cap on its crown prevents it from collapsing on itself and preserves its shape. You don’t want any creases as this can wear out the material.

An alternative is to place the swim cap on a hat stand, if you have one of those. This also helps the swim cap maintain its shape, but make sure it stays out of the sunlight. Ideally, your swimwear should be stored in a cool, dry area.

Frequently asked questions

How long should swim caps last?

Swim caps can last anywhere from a month to a few years. This large range is due to a variety of factors such as the type of swim cap you have (e.g. Latex vs silicone), how often you wear it, and how well you are maintaining it.

Let’s start with materials first. The two most popular types of swim caps are latex and silicone. Between these two, silicone swim caps are more durable and can potentially last years, assuming proper care. Latex swim caps are not as durable and may only last a few months at a time.

Naturally, if you wear a swim cap more often, it will get worn down and will reach its natural lifespan much faster than a swimmer who only wears it occasionally. Thus, how “long” something lasts is not the best question to ask; you should be asking “how many times can it be worn” before it breaks down, in which case latex can be worn dozens of times, silicone can be worn hundreds of times.

Finally, failure to properly clean the cap, dry it, and store it properly will reduce the swim cap’s lifespan. Maybe one could have gotten significantly more use out of their cap, but neglect caused it to become brittle or to grow mold, and that’s not really the caps’ fault.

Why is my swim cap sticky?

A sticky swim cap is a bad sign. As we mentioned, avoid leaving your swim cap in direct sunlight. Excessive heat can cause the materials to break down (melting in this case) and becoming sticky. Once this happens, there’s no way to “fix” this problem other than to get a new cap.

The sun is not the only problem. Storing your swim cap in a hot room is enough to cause it to become sticky. One time during a particularly bad heat wave, all of my swim caps melted and I had to replace all of them. This is highly uncommon but not unheard of so pay attention to where you store your swim caps.

Can I clean my swim cap using a washing machine?

Absolutely not. If swim caps can literally melt when left in a hot room, do you think they can survive the washing machine? Latex, rubber, and silicon are materials commonly used to make swim caps and they are not suitable for the washing machine.

Even if you have a more durable swim cap, putting it in the washing machine is a surefire way to wear it down and drastically reduce its lifespan. The best way to wash your swim cap is by hand, as outlined in the sections above.

Even when hand washing, you must be very gentle and make sure you never twist the swim cap when squeezing water out. Use the towel method and apply baby powder to dry it out in a gentle way.

Parting words

Swim caps are the single most replaced items for swimmers because they are delicate and sensitive. However, even knowing this, you should still try your best to keep them clean to ensure their longevity and prevent skin irritation.

You don’t even need to do anything special; just keep up with your regular care and you won’t ever have a mold outbreak. To reiterate, that just means to rinse it thoroughly after swimming and to line dry it fully before storing it back into your bag.

To reduce the likelihood of tears and punctures, trim your nails or file them down so they aren’t so sharp. Be careful with hair/bobby pins, earrings, or other jewellery that could puncture the cap. When stretching the cap over your head, be gentle so as not to tear it.

With a robust care system and some due diligence on your part, swim caps can potentially last for years, not just months. When people start to neglect maintaining their swim gear, they will have to replace them very soon. It doesn’t take much time or effort at all, so it shouldn’t be hard to keep it up.

Each time you use your swim cap, it will get worn down slightly. Over time, it will naturally tear or go through discoloration no matter how much you care for it, but mold formation is definitely not okay and is avoidable by following the tips provided in this article. If mold formation occurs, you can try to salvage the cap but the best option is to replace it with a new one.