G-W 283 Wet Under The Deck

[geost]

I have a 2006 G-W 283. All areas under the deck visible through the access ports are constantly wet. A colloidal soup sits on top of the fuel tank. The soup can be cleaned off but I wonder if other 283 or center console boat owners are having this problem and have a remedy. I'm sure this is condensation but with small access ports drying it out is a dilemna. The boat is kept in the water year round in coastal SC. (vertually no storage yards available). Had water in the tank last fall despite keeping fuel level above 70%. Fortunately, wasn't too far from the marina when the engines died. I had not checked engine mounted fuel filters in a month or so. This is our 7th boat and never had a water problem in the past. I assume that this was also a condensation problem as marina claims no water in its underground tanks. Now I'm reluctant to go offshore. Anyone encounter same problem?

GEOST

 

[choogenboom]

hi Geost - greetings from neighboring Beaufort SC. I have had the same mold (yup, that black stuff is mold) problem on both my Gradys and if it makes you feel any better, I had the same problem when my Grady was stored on a lift at my house in southern California in a area considered to be semi-arid desert.

The first problem you bring up, mold, happens because bilges by their nature are always at or near 100%RH and in the evening, as the deck cools, that moisture laden air comes into contact with the now cooler deck, condenses, and drips to whatever lies below. The problem seems to be confined to the area under the deck plates, probably because the thermal mass of a plastic deck plate is less than that of the surrounding fiberglass deck. You have a couple choices:

1. install a dehumidifier in your bilge - not practical
2. Put a moisture absorbant dessicant in the bilge. Not practical as it would need constant replacement.
3. insulate the underside of your deck plates with foam. Never tried it but guessing it would at least help eliminate the deck plates as the worst offender
4. ignore it, and pressure wash the affected areas when it suits you. Thats been my solution.

The second problem, water in the gas, is harder to ignore. I had recent fuel problems from hell (see my recent post on the bad effects of ethanol) , including water in the fuel. But on boats that I use regularly and fuel up regularly I have not seen the water in the fuel problem. I now have a GW 330 Express and BW 180 Ventura in the water year around. I have yet to have water problems in the BW but it has a plastic fuel tank which likely does not sweat as much as the aluminum tanks in the GW. My prior GW (1994 Seafarer) was in the water here in Beaufort for over a year with periodic but not heavy use and it had no water problems. Back in california the GW Seafarer could sit unused for months with no attention given to fuel levels during storage and I never had water in the gas; in fact I can't remember changing the fuel filter more than once or twice in 10 years. The new Grady 330 Express has had water problems but I inherited those from the former owner so I can't correlate how it was stored with the appearance of water.

I have done some research and other than lots of anecdotal evidence I have yet to find a well conducted experiment that shows how much water gets into a gas tank given a certain set of ambient conditions.

My gut tells me your water in the gas is coming from sources above and beyond condensation and the most likely is the oring under the fuel cap. We get plenty of rain and unless that oring is in good shape water will run straight into the tank. A second but less likley source is water pumped in with the gas when you fueled up. My neighbor owns a dozen or so exxon stations and he told me in great detail how their tanks are slanted with the fuel pick up on the high side and daily samples taken from the low side looking for water. Marina fuel docks may not be as careful but seems unlikely they are the source of teh water.

Elsewhere on this forum is good advice on aftermarket Racor filters with clear site bowls on the bottom and built in drains as well. A fine insurance policy against future water problems.

Chris

 

[Hookup1]

Wet under the deck

I'm sure you have mold and some of it is condensation related but my experince has been the access ports are notorious leakers.

After washing my boat one day I looked into the battery compartment. Water was dripping down! I pulled the access port rings off and re-caulked them. I changed the O-rings and lubed them. Pulled the deck and re-caulked. Nice and dry now.

It may not be the complete solution but it is likley part of it.

 

[Tashmoo]

To resolve the moisture problem all you need to do is move a small amount of air from the bilge say one air change per hour. As a point of reference small computer sized fan running all the time would be more than enough volume the problem is finding a low power draw fan that will hold up to salty conditions and then finding a place to mount it.

I had a wet moldy basement and lived with a dehumidifier for years until I installed a 100 cfm computer fan in the door from the basement into my bulk head to heat and cool a place for the dog to hang out. The dog loves it and I have not needed to use a dehumidifier in years. All that was needed was to move the saturated air out and let fresh air migrate in through the million places that it can with a slight negative pressure inside.

 

[choogenboom]

Tashmoo - great suggestion!

Chris

 

[NOTHING ELSE MATTERS]

What i had done on my express was, bought a small plastic fan from boaters word(around 9"-10") and a 3 foot thingie(i don't know what is called) that you plug in and gets warm, between the warm air of the bar and the fan circulating air all the time never had a problem of mold in the cabin or the bildge.

 

[BobP]

Another member previously reported Grady HQ recommends periodic rinsing of the tank spaces below deck, etc. You may want to do a search to find the thread.

Even though your boat is very young, be careful when considering the use of heating devices below decks (exception is cabin on cabin boats), a gas leak can still occur, there are plenty of hoses, valves, filters, and fittings around, as well as half-assed mechanics who attent to them. Gas vapors are highly flammable and explosive.

In the off season, before considering leaving bilge doors open and deck covers off etc, as a means to vent these spaces, critters may decide that you have placed out the wlecome mat for new residents. If they move in, you will wished you had lived with the mildew instead.

Bilge spaces are meant to be damp places, Grady even attempts to seal these areas from ventilation. Venting only works when it is already wet down there, but when it becomes dry, leaving it open will allow the wet to come on faster, on a daily cycle.

I would say in general, a boat stored outdoors in the sun is better off than one in the shade outdoors, with respect to dampness/ mildew in cabin and below decks.

 

[seasick]

The fan idea is only helpful if the outside humidity is less that that in the bilge. Oftem it is but in some locales it may not be. My point is that if you move wetter air into the bilge that was dry, it will get wetter.

 

[choogenboom]

That 3 foot thingy is probably called "Golden Rod" - they make those a mile from my old house in Oxnard, CA.

http://www.drytheair.com/xcart/store/ca ... Watts.html

Note that the golden rod and other space heater like it are NOT de-humidifiers as the manufacturers claim. They are the opposite. With any standing water in the bilge they will actually result in more, not less, water vapor in the air. They are heaters. Coupled with a fan to force air changes in the bilge you may or may not improve the condensation and mold problem, depending on a number of variables including fan CFM, inside air temperature and %RH, outside air temperature and %RH and the thermal conductivity of the walls of the enclosure.

I sell a lot of monitoring equipment to building scientists, and the problem we are grappling with here is parallel to that of crawl spaces (and to a lesser extent attics) of houses. There is a long history of people applying many theories to crawl spaces and attics that sounded fine on paper but invariably ended in mold. The current best practice for both crawl spaces and attics is to seal and insulate them and condition their airspace the same as you would any other air space in your house. Unfortunately boats are not often plugged into AC power making power hungry solutions such as dehumidifiers a non-starter, and bilges of boats that are in the water are virtually impossible to keep dry between either deck leaks or below the water line leaks and the fact that bilge pumps often leave 1/2" or more of water in the bilge.

For those of you that are curious, I just placed two of my company's wireless humidity sensors on my 330 Express. One sensor is in open air at the helm station and the other is in the bilge on top of my auxiliary tank. They are logging temperature and %RH every 5 minutes. If you want to see the data go to our web site https://www.omnisense.com/sensor_select ... larmOnly=N and login with username guest1 and password omnisense. You can see the current and historical data and graphs of the %RH in the open air and in the bilge. To see a graph click on the value you want to see a historical graph of. Note the sensors went in 10/31/2008 at about 9 am. This is step one in the process to quantify the problem we are trying to solve. Note also that there is standing fresh water in my bilge – best of my knowledge I do not have any below the water line leaks.

I recently replaced the o-rings on all my deck plates and schmeared them with Vaseline. At that time I had water and mold below the deck plates on top of the fuel tanks. Like a few others have noted here, I had seen water running into the bilge via my “sealed” deck plates when spraying them with a hose. I noted this morning that the area below my deck plate was dry and mold free. So could be the worst offender is leaking deck plates – a simple problem to solve.

Once I have accumulated a decent %RH data history for the bilge I’ll report back in.

Chris