Mildew during lay up.

[Colwyn D]

I get mildew forming on the woodwork while boat is laid up. It's not a big deal as cleans off easily but I've picked up a packet of mildewcide from Ace hardware, Sun Pac. Active ingredient is paraformaldehyde. Anyone know if there is likely to be issues leaving this in the boat for a couple of months?

 

[Boatsb]

ventilation is a good thing. Mildew needs moisture and the mildewcide does not fix that.

http://www.sciencelab.com/msds.php?msdsId=9927382


Not good for humans.

 

[Walter P]

Keep the air moving with a small fan. You don't need much, just enough to move air around. Also if
you wipe down everything with any good cleaner just before lay up, keep moisture out and air moving
the chances are that you won't have those issues. If you have sensitive allergies it would be best to
wear a mask while cleaning mold. Any physical disturbance of mold can cause it to "bloom" and all the
spores become airborne.

Walt

 

[Colwyn D]

Thanks for the suggestions. I have kept the boat in Florida for ten years and find providing air circulation difficult without letting driving rain in. Boat is on the hard during lay up and no electricity is available for fans etc.
I have considered making a solar powered fan to fit in place of the engine hatch, salon floor, and force air out through the engine room but the mildew killer seems an easier solution, at least until I find it's caused all the plastic to go brittle, metal to corrode and whatever else comes with some of my good ldeas.

 

[jim rosenthal]

You would be better off with those nonpowered devices that absorb moisture, and rigging a fan inside the boat; I think moving the air is more important than letting fresh air in, although getting fresh air means something, too. I leave a fan running all the time in my boat, whether she's at the dock or at the yard, and so far no mildew problems. The devices that collect water will have to be emptied from time to time, but the labor is a lot less than removing mildew, and a lot less dangerous to you. I would not put anything that emits paraformaldehyde in the boat.

There are some low-wattage heaters made for storing boats, also, look in Defender or (gag) WM.

 

[bobk]

Thanks for the suggestions. I have kept the boat in Florida for ten years and find providing air circulation difficult without letting driving rain in. Boat is on the hard during lay up and no electricity is available for fans etc.
I have considered making a solar powered fan to fit in place of the engine hatch, salon floor, and force air out through the engine room but the mildew killer seems an easier solution, at least until I find it's caused all the plastic to go brittle, metal to corrode and whatever else comes with some of my good ldeas.

First, get a temperature humidity display that shows instant values as well as min and max over the previous 24 hour period. These are about $25 on the internet. Seal all vents, ducts etc that can allow outside air into the boat using preservation tape. It's pricy but doesn't leave a tape residue except on vinyl. You want to get the relative humidity below 60%. Monitor your situation. If the RH is too high, set a gallon bucket of a dessicant (Walmart or Home Depot) in each space. If you are well sealed, this ought to work. You may need to replace the dessicant once during the layup period. Be sure to leave the closet doors open.

If you need to do more, check out 'No More Mildew' from National Allergy on line. It can be applied to all sorts of surfaces and lasts a long time.

BTW, formaldehyde vapors are nasal carcinogens.

Bobk

 

[Boatsb]

Hey Bob.

Your a plastics chemist not a mildew expert.

And Jim is just a doctor.

No one's going to follow your directions if the internet says otherwise.

 

[bobk]

Hey Bob.

Your a plastics chemist not a mildew expert藍.

And Jim is just a doctor. 洛

No one's going to follow your directions if the internet says otherwise.

Scott, As they say, YMMV. But hey, BTW, I'm a doctor too, but in chemistry . Did I ever tell you that my condo had been destroyed in a hurricane when I bought it. The building's contractor was not able to remediate the black mold, so the place was sold cheap. I remediated the mold my self on the first try and it passed several tests to prove it. So maybe I'm a mildew expurt too?? Organic chemists tend to be jacks of all trades.

Bobk

 

[jrbrein]

Also, fix any deck leaks and get the water out of the bilges. This is a constant source of humidity.

Jon

 

[jrbrein]

Regarding deck leaks and water ingress. Since taking possession of my 43' DCFB, I have been chasing down leaks on the boat during gentle rains, hard rains, wind driven rain from every direction and the boat flexing and straining against the dock lines, melting ice and snow, etc...

I have found water coming in from all sorts of places.

But, I am happy to report that I am winning the battle!


Jon

 

[carolinacoast]

2 suggestions: solar fan to move air, or solar power to a battery source to run a fan.
When I am on the hard with no power, i buy boxes of damp rid's. I want that moisture gone, as I am terribly allergic.
I have used this method for 20 years, and I can get about 3 weeks from these.
https://damprid.com/

I used to buy the bulk ones and refill (that is all they made). 1 would always spill or get a crack and the brine would ooze on carpet. yuck. I prefer the self contained with hangers. For hurricane Matthew, was on the hard, no power, lots of humidity. Had 6 boxes spread around. no mold. $40.. priceless.

 

[SEVEN]

Move to a yard that has power and run a small amount of heat and a fan or two.

 

[Reefgeorge]

Living in Florida and being allergic to mold I have had to learn a thing or 2 about mold management.

Mold needs food and moisture to grow and some varieties do better in darkness. To start, what BobK said about a humidity meter. It's a losing battle if the interior humidity is too high. Less than 60% is mandatory, less than 50% is better. I use an extech meter on my boat. I actually find that a sealed boat that is getting heated by the sun through the windows produces a lower humidity with less problems. Leaking Ac ductwork, open areas to the engine room, etc make this more of a challenge. There is a trade off here of course because the sun can make stuff fade or breakdown.

Next is food. Before layup think about vacuuming everything including drapes and couches. Also wipe down All dusty surfaces and don't coat wood or anything else with something that is mold food like certain oils or polishes.

As mentioned here also open everything so that every space gets warm and has lower humidity. This is the whole idea behind those closet rods that you plug in, it slightly raises the temperature and lowers humidity. I've never found circulation to be important unless it is to sweep out a trapped area of high humidity. Totally still warm air at 45% humidity will do the trick.

George

 

[Colwyn D]

That's been a fantastic amount of information for me. Thanks for all the replies.