After a backpacking or camping trip, it’s too easy to just toss gear into heap in storage and forget about it until the next trip. Unfortunately, this type of negligence will destroy your tent faster than a hungry bear, a pack of mice, or a murder of crows looking for an opportunity in the backcountry.
Aging tents whose finishes are old and deteriorating are often the fastest to populate with mold or mildew spores and even bacteria (which results from deteriorating tent coatings). But it can happen to new tents put away damp or dirty, too. You’ll know how bad it is by its smell. If your tent has developed a wretched stink, the easiest and cheapest cure is to pre-wash it in a utility or laundry sink filled with water and 4 cups of baking soda mixed in. Soak for about 2 hours. Pick it up and hold it to your nose to check for lingering odors. Once the stink is gone, rinse it well, and hang it up to dry, or throw it in a dryer on the air dry setting.
Another option is to use an all-in-one disinfectant, fungicide, virucide, and germicide. If you go for this big gun approach (this particular EPA registered product is effective against a wide range of microbes), set up the tent on hard surfaces, spray it down and let it sit for at least 10 minutes before moving on to washing it. But keep in mind some people are sensitive to these chemicals so you really need to double rinse your tent if you go this route.
Pre-washing tents with enzyme-based cleaners is the best way to get stink out of old tents, despite what many people claim. Enzymes are powerful scavengers of microbes. Try this before going for the big gun treatment outlined below. Follow directions on the bottle for amounts.
Spot treat grease stains with an organic citrus-based solvent (rinse well after applying to individual spots). Remove black stains caused by flaking metal from aluminum poles by spot treating with a water-based silver tarnish remover (typically used for jewelry and household goods).
High-quality new tents are typically treated with a Durable Water Repellency (DWR) finish with a urethane coating (on the fly and on the inside of the tent body) to make it waterproof. DWR resists water, making it bead up and roll off like the wax finish on a car. In time, as the tent ages, the DWR disintegrates and the fabric begins to absorb more water, which breaks down the urethane coating.
Observe the state of these coatings, and use your nose to guide your cleaning procedure:
For tents with light musty odors, and those that haven’t been cleaned in a while, use a cleaner specifically designed for tents, like McNett’s Revivex or Nikwax Tech Wash, to remove dirt and residues that might otherwise prevent waterproofing polymers (that you’ll use to recoat the tent) from bonding to the fibers that comprise the tent fabric; you do not want to try to re-coat over dirt or stains. Tent cleaning products are specifically formulated to clean high-tech gear without diminishing their DWR finish. They remove dirt (but not necessarily grease or stains) and ensure the tent fabric can evenly and consistently take up any new treatment. Avoid using dishwashing liquid, laundry boosters, spot removers or bleach on tents. Such products can interfere with the DWR finish, or worse leave a film that will make the tent difficult to properly recoat.
Fill the sink with water, mix in the cleaning product per instructions and gently scrub tent fabric all over with a soft sponge, by hand. Then squish and squeeze the fabric for about 10 minutes. Rinse thoroughly, and toss in the dryer; dry on the air-only setting. Drying it in a dryer will keep it free from airborne dust and pollen. Don’t set it up on grass or dirt. Some retailers recommend this, but if you plan to recoat it, any debris or dust that have clung to the fabric will create an uneven surface when you re-coat it.
If your tent still has intact waterproofing, you can skip pre-treatment/wash and go straight to a DWR-safe cleaner followed by a wash-in, brush on or spray-on re-coating product. Use a utility sink or a large tub to hand-wash the tent (don’t use a washing machine, which can overstress seams and netting on older tents).
If the tent has already lost all its guts and glory (finishes/coatings), you can safely pitch it in the washing machine; follow cleaning directions on the bottle of tent specific cleaner.
If it’s peeling, it gets more complicated, but well worth a try. Scrub off as much of the peeling urethane as you can with a bristled brush and then throw it in the washing machine to try to remove the rest. You may not get it all off, but try to get as much as you can so you can virtually start over.
Set the tent up on a clean, hard surface and use a seam sealer to first coat all the seams. Then apply two coats (let the first dry 24 hours) of a polyurethane (PU) sealant (a good option is Tent Sure Tent Floor Sealant ). A foam brush makes application easy, and produces a clear and flexible finish that will make your tent look almost new without nary a stink.
Consider storing your tent in a duffel instead of its original storage sack. Air circulation will ensure a fresher smelling tent the next time you pull it out to use it. In fact, the best thing you can do for your tent is to store it in a dry, loosely packed state, preferably in a bag with mesh top to help prevent moisture that leads to mold and mildew, and one that’s big enough to minimizes stress on the tent’s fabrics, seams and zippers. Finally, don’t store your tent in a musty basement or un-insulated garage (where heat fluctuations will do a number on tent components). Consider storing your tent in your bedroom or hall closet instead of a garage, basement or attic.