Mildew in the Cabin

[pdqaltair]

I've been doing some research for PS Magazine on mildew and I have a question. But first some background:

--We've looked at CaCl2 and other desicants. This is only going to keep the cabin dry if things are tight.
--We've looked at dehumidifiers vs. CaCl2. There are some small units that seem very useful. Article submitted.

We've started testing canvas samples:

--If kept low humidity (<60%) significant mildew is impossible to start, even if the samples are inoculated.
--Water repellant treatments help a lot. Synthetics (Sunbrella) are much more resistant than cotton. Obviously.
--Vapor treatments don't seem to do much. Perhaps some incremental difference in a situation that is nearly sterile, but we can see it.
--Bleach will kill it if you use enough (and related products), but it can grow back if the bleach is rinsed off. And you can't use bleach on upholstery or carpet.
--Vinegar will kill it and keep it away better, but use that on soft surfaces and you'll have to sell the boat... if you can.

And finally the question. It seems some very simple alkaline cleaners (TSP+borax+washing soda as well as variations) are quite effective--better than some "anti-mildew" products--for pennies. The trick is to use low concentration and not to rinse. The borax/phosphate residue is the thing. Phophates only seem to be a problem from cleaners going down the sewer (laundry) and we're talking about low volume spray cleaners that are not rinsed. Different. Sure, you can add organic surfactants (soaps) to increase effectiveness, but unless they are carefully chosen and biocide added (quat amines?) they themselves become mildew food.

What have you found most effective at preventing mildew return? Why?

[PaulinVictoria]

Good winter tarps and regular airing/sailing year-round.

[davidpm]

Originally Posted by pdqaltair

--Vinegar will kill it and keep it away better, but use that on soft surfaces and you'll have to sell the boat... if you can.

What happens?

[marcusc130]

It smells like vinegar..... Forever.

[T37Chef]

Kanbera Gel, a tea tree derivetive...you have clean first but it will kill the rest and will keep it that way. our boat has never smelled so good since using it

[sidney777]

DG home (brand) mold and mildew remover from Dollar store @$1.50 . Spay and leave it on, or wipe it off.

[pdqaltair]

Originally Posted by T37Chef

Kanbera Gel, a tea tree derivetive...you have clean first but it will kill the rest and will keep it that way. our boat has never smelled so good since using it

Yes, I hear that, but testing suggests it will only be effective in small areas with little ventilation (if there is effective ventilation it dissipates too quickly) that are dry and clean. I think we will see that it is a supplemental tool useful in some cases, after other steps are taken.

As you have suggested, it will not eradicate mildew from a damp boat.

[pdqaltair]

Originally Posted by sidney777

DG home (brand) mold and mildew remover from Dollar store @$1.50 . Spay and leave it on, or wipe it off.

Specific link? Can't find it on DG site.

[hellosailor]

chef, there's a strong biocide in tea tree extracts. Nail salons use it to cure nail infections, both fungal and bacterial. No idea what's in the gel but I'd bet the same active ingredient, which seems to sublimate very nicely, the tea tree oil can be quite pungent.

pdq-
I've found that if you keep things fairly clean and dry, good ventilation will stop mildew. But then again, I don't hang around swamps. I knew someone who used to work full time for Ford, going around the country examining AC systems in cars that had perennial mildew problems. They had no universal cure either, but using toxins (copper or tin or silver in micro-form or as base materials) seemed to be the best way to stop it from getting started, but if moisture built up, the crud would always follow.

Bleach of course will also kill cotton and some other fabrics.

But you missed two killers, ozone and UV-C. Like every other mildecide, they will kill it--but the spores are in the air all the time, everywhere. Killing it just provides good food for the next crop, unless you also clean away the food, and change the environment to someplace they won't grow. (By keeping it dry, or toxic, or outright wet.)

[capecodda]

One winter storage cheap solution is kitty litter in buckets or pans (the more surface area the better) in all the cabins. Even sealed up the boat can start the season with no mildew to cleanup. We also remove all fabrics, cushions, etc.

But you may be driving for solutions that work while commissioned, we haven't had much problem with that up here.