Uggh. Mold and mildew. How do you get rid of them in hot and humid climates?
I don’t have the perfect answer. What I do know is that boat interiors seem to be fertile breeding ground unless you’re running an air conditioner or dehumidifier. NOTE: I am NOT talking about any types of toxic mold here . . . just “normal, everyday mold” that shows up in boats in humid climates.
When we were cruising in the Sea of Cortez, we didn’t have a major problem with mold and mildew as it’s relatively dry there (the Baja peninsula is a desert). But when we spent a summer in El Salvador, we had a bit of a problem. This winter, in the Florida Keys, was the worst I’ve experienced . . . and from the email I’ve gotten, it seems that many people were fighting mildew all over the US and through the Caribbean.
Here’s what I’ve learned, first in the area of prevention and then in cleaning:
We haven’t found anything to be 100% effective in prevention of mold and mildew. Three items that are frequently mentioned – bleach, vinegar and tea tree oil – did absolutely nothing for us (ditto for many other cruisers I’ve talked to in south Florida). What has helped:
- Really improving ventilation with fans, exhaust fans, wind scoops and just keeping hatches and port holes open.
- Moving things around and getting rid of even more clothing, bags, extra towels and bedding so that there is more unrestricted air movement in the boat as well as less “stuff” to get mildewy.
- When possible, washing anything that did have mold or mildew on it in very hot water, which does kill the spores.
- Do laundry more often, particularly of sheets, towels and anything else that may get damp or sweaty. Again, I use hot water whenever I can.
- Hang towels and rags out to dry whenever the weather allows (don’t let them sit damp in the boat).
- Rinse anything that’s been in salt water off before coming in the boat (salt attracts and holds moisture): feet, shoes, swim suits, dog. Unfortunately, sometimes we have a wet dinghy ride and our clothes get soaked . . . and it’s just not feasible with other boats nearby to strip off all the wet clothes on the back deck! But we try to stay as close to the door as possible and toss the wet clothes into the cockpit so the salt water doesn’t get in the boat.
- We use Concrobium liberally on fabric, wood and fiberglass. It’s sold in home improvement and hardware stores in the PAINT department, not cleaning supplies. Spray it on and as it dries it kills the mold and mildew spores, and continues as a preventive. You’ll see reviews where people say it totally stopped mildew but that’s when they were able to eliminate the conditions that led to mildew . . . on a boat, it seems to help a lot, but since you can’t eliminate the humidity, mold and mildew will eventually come back if you don’t keep re-treating. About once a month, we go through the various areas of the boat and spray, moving storage crates and cleaning them as we go, too (note: you have to leave it wet so it kills the spores as it dries). If you can’t find Concrobium in a store near you, you can get it on Amazon:
- Concrobium is safe to use on fabrics and we find it has helped a lot with mildew on our life jackets, foul weather gear and hats. No, it hasn’t totally eliminated problems – but they are far less severe than before we were using it. We also are making a big effort to let all these dry outside before we bring them inside the boat.
Mold and mildew stains are tough to get out of fabric and wood. Items that can go in a washing machine with hot water do pretty well although there may still be a little stain left. Items washed in cold water don’t do nearly as well.
Concrobium isn’t marketed for removing stains, but we’ve found that it helps considerably with upholstery and “fake leather.” It does a great job on fiberglass and plastic surfaces – spray it on, wipe off, then respray and let dry to inhibit further growth.
Borax (sold for laundry) is also helpful. Mix it with hot water and wipe down areas with mold and mildew. Do not rinse off. The borax will both clean it and do some good in preventing reoccurences. Used on fabrics, it will lessen stains as it dries. You can often find borax powder in the laundry aisle of grocery and big-box stores, or buy it on Amazon:
Bleach can help some items but can cause its own problems with discoloration — it can remove color and will turn some white items yellowish. If you want to try a dilute bleach solution (I use about 10% bleach – or less), test it first on a hidden spot.
There are numerous “mold stain remover” sprays on the market. Most work with bleach. We haven’t had much more success with them than with just using borax, bleach or Concrobium but depending on the material you’re working with, you might. Most of these are sold with cleaning supplies in home improvement and hardware stores.
If you are particularly sensitive to mold, have a lot of it on your boat or have respiratory problems, I’d suggest using a sanding dust mask at a minimum . . . or perhaps a true respirator if you have one.
If you’re in a hot and humid area, you’re almost certain to have to deal with mold and mildew. And it won’t be a one-time battle: it will be ongoing. You can kill off the existing mold and mildew, but as long as the conditions exist, it will keep coming back. The tips here will lessen the problem considerably, but I don’t know of anything that will eliminate it permanently while still allowing you to be aboard short of air conditioning or a dehumidifier . . . and those aren’t practical without shore power.