How to dry the air

I just purchased a 42 ft trawler that I will be living on in Southern Ca (Oxnard). I noticed that the previous owner has number of different "bags" and small plastic containers holding moisture absorbing chemicals of some sort. What is the best way to control the humidity on the water?

Also, I have a "non-stainless" 9mm pistol and a 12 ga shotgun that I will store on the boat. Is there a good way to store these firearms so they don't corrode from the salt air?

I currently use the little plastic buckets of absorbent material too and would be interested in a better way myself. As for the firearms I prefer routine old school maintenance with plenty of oil in a soft case. Mine are lamb skin wool lined.

If you can put the items in a sealed locker, then a bag of adsorbent will do a decent job of drying out the area. Better though to wrap the items in plastic, drop in a bag of adsorbent and seal the bag.

David

A de humidifier , over the sink , operating 24/7 works.

The way to keep the air dry is simple.

Ventilation

Anything else you do is just making up for poor ventilation.

There are allot of methods to ventilate a boat. In some locations the little sun powered units work.

In other locations passive ventilation works.

On our boats I've found that I like power ventilation. Vetus makes a really nice power ventilator for a boat. Costs <$100 and draws if I remember right something like 50 miliamps. A couple of these in the right place will do the trick.

ksanders said:

The way to keep the air dry is simple.

Ventilation

Anything else you do is just making up for poor ventilation.

There are allot of methods to ventilate a boat. In some locations the little sun powered units work.

In other locations passive ventilation works.

On our boats I've found that I like power ventilation. Vetus makes a really nice power ventilator for a boat. Costs <$100 and draws if I remember right something like 50 miliamps. A couple of these in the right place will do the trick.

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Read "The warm dry boat", everything you need to know about ventilation.

mikekomm said:

Also, I have a "non-stainless" 9mm pistol and a 12 ga shotgun that I will store on the boat. Is there a good way to store these firearms so they don't corrode from the salt air?

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Clean them well and make sure everything has a light coat of CLP on it.


As for storage, you can use anything from a $10 SackUps or Bore Stores silicone impregnated gun sock to a $200 Pelican waterproof case.

There's also a company called "Inhibitor" (theinhibitor.com) that specializes in this sort of thing and has what are supposed to be really good chemicals and storage solutions, but I've never used them personally.

I bought one of those little Evadry dehumidifiers this fall and it works great. Yes, I have read "A warm dry boat", a few times (our local library has a copy) but the dehumidifier has worked better for me this winter than ventilation has in the past.

Northern Spy said:

I bought one of those little Evadry dehumidifiers this fall and it works great. Yes, I have read "A warm dry boat", a few times (our local library has a copy) but the dehumidifier has worked better for me this winter than ventilation has in the past.

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The Eva-Dry 2200 worked well for us also. We left the boat in FL for 1 month plus last August. Came back and everything was dry and no mold or mildew. We modified the reservoir so it would drain into the sink.

Anything above 60% relative humidity will breed mold. It really depends on where you are and what the RH is in the air. Sometimes the RH can be so high that introducing it into your environment is not only bad but your asking for trouble if you have non moving air. There are several things I would suggest, I have dealt with a mold remediation in a basement once and don't ever want to go through that again. After having conversation with a micro biologist about the presence of mold and how to avoid having it in my living situation here is what we came up with. Very simple and will always keep mold at bay,
1. If there is mold present you need to clean it up. Wear a mask and clean with bleach. Google how to properly clean up mold. There are several methods but best is a mild solution of bleach 1 cup to say a gallon will more than work. (Probably over kill but it's mold)
2. Purchase a RH meter at your local hardware store and monitor. Often RH meters are built into the nicer temp indoor outdoor gauges. I have one and monitor it several times a week.
3. Move the air - simple mold won't establish itself if it's moving. Mold is always present in the air. It's warm, stale air that allows it to establish.
I have five fans in my boat. A few pancake dehumidifiers a couple of chemical dehumidifiers and three 4" fans.
If your RH is above 60% or higher you need a dehumidifier, try a few pancakes if that doesn't work then get a small one that can drain directly into your sink and run it. Make sure to buy a few fans so all the air is circulating and being adjusted to your RH levels. I usually like about 40-45%. To dry and you risk damaging your wood and health.
Also - be very careful with the chemical dryers the water collected from them can be corrosive (dispose properly).
Also one of the projects this summer is to repaint the interior cabinets as there was mold present from the PO. I cleaned and now keep the drawers open when away from the boat. Repaint with a bilge paint that has a built in mildicide. No worries if I continue with my current practices.

I have a portable By Arrow Pneumatics it has a drain so I sit it over the galleysink, I got it about 10 years ago. I had to have a local A/C guy service it 4 years ago.

Love the EVA dry! that is a great mod - I think I am going to partake your solution for long term draining is great!

Awesome they even have a 12v for the Eva
Eva-Dry 2200 Electric Dehumidifier

When looking for a dehumidifier be aware of the temperature you will operate the unit in. Most dehumidifiers will quit working at around 65 F. There are dehumidifiers that will go down to 45 - 50 F and are usually called Basement Dehumidifiers. This is what I have in my boat here in the PNW.

When we used to live on our Defever 45 in the Seattle area, the dehumidifier made a world of difference in livability. Before the dehumidifier I was constantly wiping the moisture off the glass after cooking or even breathing in the winter. After the dehumidifier this problem went away.

I've suggested this to every liveaboard I know and those that followed my advice where surprised at the difference in livability.

bshillam said:

Love the EVA dry! that is a great mod - I think I am going to partake your solution for long term draining is great!

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Did the same mod, highly recommended. Mine was filling up in a few days otherwise.

Which model of the EVA is that? Have you experienced the same problem with it shutting down due to temp? I usually like to keep my boat about 50 when I am not in it.

ys, all this talk about mold high humidity and the like is great, but the simple fact is that mold will not grow in places with good ventilation.

Just because you have high humidity, does not mean you'll have mold.

In Seward Alaska, we have similar weather to the greater Seattle area, it just rains more.

Its simple, keep your boat well ventilated, and you will not get mold problems. Your boat will always smell and feel fresh, because its filled with fresh air.

Do not ventilate and you'll need to get the humidity down to a point where mold growth is not possible, but you'll still have a boat filled with stagnant air.

ksanders said:

The way to keep the air dry is simple.

Ventilation

Anything else you do is just making up for poor ventilation.

There are allot of methods to ventilate a boat. In some locations the little sun powered units work.

In other locations passive ventilation works.

Click to expand...

If you live in a very humid area, ventilation just replaces humid air with more humid air. Many marine AC units have a dehumidify setting and that's what I use. Other than that, a separate dehumidifier would seem to be the best solution.

WesK said:

If you live in a very humid area, ventilation just replaces humid air with more humid air. Many marine AC units have a dehumidify setting and that's what I use. Other than that, a separate dehumidifier would seem to be the best solution.

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Southcentral Alaska is as humid as it gets.

Replace humid stagnant air with humid fresh air and no mold grows.

People would rather, it seems to jump through all kinds of hoops, when ventilation solves all the problems.

ksanders said:

Southcentral Alaska is as humid as it gets.

Replace humid stagnant air with humid fresh air and no mold grows.

People would rather, it seems to jump through all kinds of hoops, when ventilation solves all the problems.

Click to expand...

Yes, keeping the air flowing is mainly it. We have quite high humidity here in Queensland, but I find a solar-powered extractor fan (not surprisingly called a solarvent), keeps the mildew away - costs nothing to run. I have two...one in the for'd hatch, the other is that round white porthole looking thing on the front face of the flybridge. They operate even in overcast conditions.

bshillam said:

Which model of the EVA is that? Have you experienced the same problem with it shutting down due to temp? I usually like to keep my boat about 50 when I am not in it.

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Mine is the little 1100, but I have a little boat.

I keep a bit of heat in my boat as well, maybe in the mid-40s F. I've never had it freeze up when the oil filled heater was on. But I have had it freeze up when the boat was, well, below freezing during the early cold snap we had this fall, when I didn't have the heater on. It looked like it was trying to ingest a snowball. But as it is a peltier effect unit, it doesn't matter. I just put it in the sink, snowball down, so the meltwater didn't get into the unit.

My RH reads ~50% when I go down and check the boat. Typically the RH outside is >80% where I live in the winter.

I went with a small Peltier Effect dehumidifier like the Evadry. I also installed a hose in the tank to allow it to drain into the sink. I didn't have a fitting to put in the tank so I just drilled a hole slightly smaller than the OD of the hose, shoved the hose in the hole and it's been draining fine ever since. I used aquarium air hose.

I thought about a solar vent but decided not to cut a hole in my hatch which was the best place for me to put one.

I have several cabinets that would not get any ventilation until I open them. Keeping the air dry is the key. I would have to dissagree with just ventilation. Close up a cabinet in a high humid area and put something to culture mold and I'd be a betting man that you would get something quickly in a closed up area of the boat.

I have 2 of those oil-filled heaters, open all the hatches and compartments and leave some of the windows open a crack. No growth.

Remember too that when it's nearly freezing or is freezing there is virtually no humidity in the air.

Here in Fl where summers are 100+F with 100% humidity mold is a problem.

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Yes not very yachty , but as a replacement hatch cover , these are very effective.

Since they run almost 24/7 there are loads of air changes per day.

Sunlight pouring in the windows heats the interior , alowin the relative humidity to drop.

IF the interior walls can be kept from dripping condensation , most of the mold hassle goes away.

Xsbank said:

I have 2 of those oil-filled heaters, open all the hatches and compartments and leave some of the windows open a crack. No growth.

Remember too that when it's nearly freezing or is freezing there is virtually no humidity in the air.

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My recollection of oil heaters is they add quite a lot of moisture to the air as they burn. I certainly would never leave any heater like that unattended. Then there is the issue of rain getting in through opened hatches, and not being secure, so I guess you mean only while on board, which suggests you are a liveaboard. The original query was to do with boats left closed up, and how to avoid condensation, and therefore mildew etc, I think.

Peter B said:

My recollection of oil heaters is they add quite a lot of moisture to the air as they burn.

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Oil filled heater... It's a radiator. Ideally, no burning involved.

Pete, I think they are talking about electric heaters like this:
Pelonis Oil Filled Heater
No flame or exposed heating elements.

Ventilation may stop mold growth but you still have humid air that will condense on cooler surfaces causing rust, corrosion and wood swelling and rot. And you're bringing more of it into the boat.