How to Wash and Care for Your Swim Trunks (So They Last)

Swim trunks are exposed to chlorine, salt water, sunscreen, and UV radiation on a daily basis, all of which degrade fabric, fade colors, and break down elastic over time. The good news is that proper care can significantly extend the life of your trunks. The key rules: rinse immediately after use, wash cold gently, never put them in the dryer, and let them air dry away from direct sunlight.

⚠️WHY SWIM TRUNKS NEED SPECIAL CARE?

Most swim trunk fabrics are made from polyester, nylon, or a blend of both, often with added spandex or elastane for stretch. These materials are durable and quick-dry by nature, but they have specific enemies:

• Chlorine breaks down elastane fibers, causing waistbands and liners to lose their stretch

• Salt water leaves mineral deposits that can stiffen fabric and accelerate wear

• Sunscreen (especially chemical sunscreens) can stain fabric and degrade fibers over time

• Heat is the biggest enemy of elastic — hot water, hot dryers, and direct sunlight all shorten the life of the waistband and liner

🔑 STEP-BY-STEP CARE GUIDE

Step 1: Rinse immediately after use💧

As soon as you're done wearing them, whether at the pool or the beach, rinse your trunks in cold fresh water. This removes the majority of chlorine and salt before they have time to set into the fabric. You don't need soap for this step, just a thorough rinse.

Step 2: Hand wash or machine wash cold 🧼

For a quick clean after the beach or pool, hand washing with a small amount of gentle detergent is ideal. If machine washing, use a cold water setting and a gentle or delicate cycle. Put your trunks in a mesh laundry bag to prevent friction damage.

Step 3: Use the right detergent ✅

Use a gentle, low-fragrance detergent. Avoid detergents with bleach, optical brighteners, or fabric softeners, these can damage the fibers and fade colors faster. A small amount goes a long way.

Step 4: Never use a dryer 🚫

The heat from a dryer is one of the fastest ways to ruin swim trunks. It degrades the elastic in the waistband, shrinks the liner, and can cause permanent warping of the fabric. Always air dry.

Step 5: Air dry in the shade🌿

Hang your trunks in a well-ventilated area away from direct sunlight. UV rays fade colors and further weaken elastic fibers. Indoors or in shade is ideal.

Step 6: Store properly👕

Once fully dry, store your trunks flat or loosely folded. Avoid cramming them into a tight drawer or storing them while still damp, this can cause mildew and permanent creasing.

CARE CHEAT SHEET 📊

 

TAKING CARE OF THE LINER

If your trunks have a compression liner, wash them inside out to reduce friction on the liner fabric. The liner is made from a stretch fabric similar to athletic wear and can lose its elasticity faster if washed aggressively.

If your trunks have a mesh liner, check the liner after washing for any bunching or pulling. Mesh is delicate and can snag in the washing machine, this is why a mesh laundry bag is especially important.

HOW OFTEN SHOULD YOU WASH SWIM TRUNKS? 🗓️

🏊♂️ After every use in a chlorinated pool, rinse immediately and wash as soon as possible. Chlorine left in the fabric continues to degrade fibers even when dry.

🌊 After ocean use, a thorough rinse is usually enough for a single day out. Wash after every 2–3 uses or when they start to feel stiff.

🩳 If you're wearing them as casual shorts (not swimming), a full wash every 2–3 wears is fine, same as regular shorts.

💡Frequently Asked Questions

Can you put swim trunks in the washing machine?

Yes, but on a cold, gentle cycle in a mesh laundry bag. Avoid hot water and vigorous cycles, as these damage the elastic and liner.

Can you put swim trunks in the dryer?

No. The heat from a dryer degrades the elastic fibers in the waistband and liner and can permanently warp the fabric. Always air dry.

How do you get sunscreen out of swim trunks?

Apply a small amount of dish soap or laundry pre-treatment directly to the stain, let it sit for 10–15 minutes, then rinse and wash as normal. Avoid rubbing aggressively, which can set the stain further.

How long should swim trunks last?

With proper care, a high-quality pair of swim trunks should last 3–5 seasons. Signs that it's time to replace them include the elastic becoming loose or twisted, colors significantly fading, or the liner losing its shape.

Can you wash swim trunks with regular laundry?

Yes, as long as you use a cold, gentle cycle. Just be sure no other items in the load have zippers or hooks that could snag the fabric.