The Hat Cleaning Bible: What I’ve Learned Cleaning Thousands of Hats Over 5 Years

The Hat Cleaning Bible: What I’ve Learned Cleaning Thousands of Hats Over 5 Years

When I started Hat House 79 five years ago, I had no idea how much time I’d spend cleaning and restoring hats. I thought I was just flipping lids. What I actually ended up doing was learning how to bring beat-up, stained, and smelly hats back to life — sometimes from the brink of the trash can.

Over the years I’ve cleaned thousands of caps. I’ve made plenty of mistakes, ruined a few good ones, and slowly figured out what actually works without destroying the hat. This guide is everything I’ve learned the hard way.

Know Your Hat Before You Touch It

Not every hat can handle the same treatment. Before you start scrubbing, take a minute to look at what you’re working with.

Check the fabric. Most hats are polyester, cotton, or a blend, and those are pretty forgiving. If there’s wool in it, be gentler. Older trucker hats from the 70s and 80s sometimes have foam inside the front panels. A lot of people try to baby that foam, but I’ve found it’s usually better to just wash it out completely. It doesn’t hurt the hat, and it’s way less messy and easier than trying to preserve old crumbling foam.

If any part of the back strap is real leather, keep it dry and clean it separately with a leather cleaner.

The bill matters too. Flick it with your finger. If it sounds hollow, it’s probably cardboard. If it feels solid, it’s likely plastic. Cardboard bills need more care and shouldn’t get soaked.

Quick colorfast test: Dampen a white cloth or Q-tip with lukewarm water and rub it on a hidden spot inside the hat. If color comes off on the cloth, don’t soak the whole thing. Spot clean only.

If the hat is rare, valuable, or you’re just nervous about ruining it, take it to a good dry cleaner. For everything else, let’s get to work.

Supplies I Actually Use

You don’t need a bunch of fancy gear, but having the right tools makes the job a lot easier. Here’s what I keep within reach:

• A clean work surface (kitchen sink works great)
• Laundry detergent (or dish soap in a pinch)
• Clean towels or microfiber cloths
• Lukewarm water
• Something to shape the hat while it dries

What I actually use now: I clean almost every hat with my own Hat Brushes. I carry three types — a soft horse hair brush for delicate panels and logos, a medium boar hair brush for general cleaning, and a hard PBT brush for really scrubbing the sweatband. I also put the hat on my Original Hat Shaper while I’m scrubbing and while it dries. It gives me a solid surface to work on and helps the hat keep its shape instead of drying all wonky.

My Everyday Hat Cleaning Spray

For hats that are just dusty or moderately dirty, I don’t always go through a full wash. Instead, I use a simple spray I’ve been making for years. It works on pretty much every fabric type and saves a ton of time.

Here’s the mix I use:

• 1 tablespoon Dawn dish soap
• 1 tablespoon isopropyl (rubbing) alcohol
• 1 tablespoon white vinegar
• Fill the rest of a 200 ml continuous spray bottle with water

Why this works so well:

• Dawn breaks down grease, sweat oils, and food stains better than most things I’ve tried. It’s the heavy lifter for actual dirt and body oils.
• Alcohol kills the bacteria that cause odor and evaporates quickly, so you’re not soaking the hat with a ton of water.
• Vinegar dissolves the salt and mineral rings that sweat leaves behind, helps deodorize, and has natural antibacterial properties.

I keep a bottle of this stuff mixed up at all times. For light jobs, I just spray it on, let it sit for a minute or two, then wipe or brush it off. It’s fast and effective.

This is actually going to be one of my next products on the site. I’m going to sell the branded 200 ml continuous spray bottles and include the recipe for free so you can keep making it yourself.

Step-by-Step Cleaning Process

1. Dry Brush First This is the step I used to skip when I first started, and it always cost me more work later. Before anything gets wet, dry brush the entire hat — inside and out. Get the sweatband good, the area where the bill meets the crown, and all the panels. You’ll pull off a surprising amount of loose dirt and lint.

2. Attack the Sweatband The sweatband is usually the dirtiest and smelliest part. I go after it first and usually clean it twice. Use the hard PBT brush and your detergent or dish soap (or my spray for lighter jobs). Scrub it thoroughly, rinse, then hit it again if it still looks rough. This is where most of the odor lives.

3. Clean the Inside of the Bowl This is the part that actually touches your head, so it needs real attention. Work your way around with your brush or a damp cloth. On mesh trucker hats, be gentle — don’t scrub so hard you tear the mesh. A damp cloth usually works better than a stiff brush on those.

4. Clean the Outside Panels Give yourself something firm to scrub against. I put the hat on the Hat Shaper and turn the sweatband out. It makes a huge difference. Use the medium boar hair brush on the main panels, but switch to the soft horse hair brush or even your finger on embroidered logos so you don’t damage them.

5. Clean the Bill Work the top and bottom. Don’t soak it if it’s cardboard. Use a damp cloth to wipe it down instead of running it under water. Plastic bills are more forgiving.

Tackling Really Bad Hats

Some hats are just wrecked — heavy old sweat stains, caked-on dirt, and that deep smell that won’t go away. When a hat gets to that point, I go nuclear.

I fill the sink with the hottest water I can get out of the tap. Then I add a liberal amount of Dawn, a full cup of OxiClean, and about a half cup of baking soda. The baking soda gives it extra scrubbing and deodorizing power.

I let the hat soak in that mix for a few hours (sometimes overnight for the really bad ones). After the soak, I scrub it thoroughly with the hard PBT brush, especially the sweatband, then rinse it well.

For spot treating really bad stains without doing a full sink soak, I use an OxiPaste. Here’s the simple recipe I’ve been using for years:

OxiPaste Recipe In a small bowl or jar mix:

• 2–3 tablespoons OxiClean
• Just enough very hot water to make a thick paste (toothpaste consistency or a little thicker)

Let it cool, then apply it to the worst spots with a toothbrush. Let it sit 15–30 minutes (don’t let it dry on the fabric), then scrub and rinse. Repeat if needed.

This combination has saved a lot of hats that I thought were too far gone.

Special Situations

Heavy Stains Dawn dish soap is still one of the best things I’ve found for tough sweat and grease stains. Let it sit 10–15 minutes before scrubbing. For really bad spots, the OxiPaste above works great.

Rust Stains White vinegar works surprisingly well on rust from pins or metal buckles. Apply it with a toothbrush, let it sit a few minutes, then rinse. Repeat as needed. After cleaning metal parts, a light coat of oil (like 3-in-One) helps prevent new rust from forming.

Odor If the hat still smells after cleaning, hit the sweatband with a laundry sanitizer. I’ve had good results with Lysol Laundry Sanitizer and OdoBan. Let it sit 20–30 minutes before rinsing or letting it dry.

Drying & Shaping (This Part Matters)

Don’t just set the hat on a table and hope for the best. While the hat is still damp after cleaning, put it on the Hat Shaper and let it air dry completely. This is the single best thing you can do to bring a hat back to its original shape. I usually let mine dry overnight.

If the hat is still a little flat after drying, you can steam it lightly and then set it back on the shaper to hold the shape while it finishes drying. Just go easy on cardboard bills.

For floppy trucker hats, once they’re on the shaper I like to give them a light spray with the blue Faultless starch. It brings back that structure without making them stiff as a board. For vintage sports hats I usually use the gold starch instead — it gives some body but doesn’t make them overly rigid.

Machine Washing Option

If the hat is colorfast and has a plastic bill, you can throw it in the washing machine. Put it in a mesh laundry bag or pillowcase first. Use cold or lukewarm water on a gentle cycle. Skip the dryer — always air dry it on a shaper.

Storing Your Hats

Once they’re clean and shaped, store them properly. I like using clear plastic bins with a clean, dry rolled-up towel or a plastic bowl inside each hat so they keep their form. If you’re stacking a bunch in one bin, the old shipping bowl fold works fine. Tossing a dryer sheet in the bin helps keep them smelling fresh.

Final Thoughts

Cleaning hats isn’t rocket science, but doing it right takes practice. The biggest mistakes I see (and used to make myself) are skipping the dry brush step, not cleaning the sweatband well enough, and letting hats dry without any kind of form.

After five years of doing this every week, I’ve learned that having the right tools makes a real difference. That’s why I made the Original Hat Shaper, why I carry three different Hat Brushes (soft horse hair, medium boar hair, and hard PBT), and why I’m bringing my own cleaning spray to the site soon.

You can find all of it at hathouse79.com.

Got a hat that’s in rough shape? Drop a comment or shoot me a message on Instagram. I’m always happy to talk through a tough one.

Let’s bring those old lids back to life.