Shades or no shades

[Hippocampus]

Our boat has translucent and opaque shades. Also one way shades (inside) for the pilot house. We are leaving the boat for 2-3 months in Hilton head.

Being new to trawlers question is: Should we leave the shades down to decrease UV? If so the translucent ones or opaque? Or leave them up to get solar warming inside the boat.

This was a non issue with sail as there’s nothing like the same amount of glass. S look forward to opinions.

 

[Xlantic]

I would leave the opaque shades down and keep out the UV which is very damaging to most surfaces.

If you are concerned about humidity inside the boat you can leave a dehumidifier running or some portholes open for ventilation.

 

[rslifkin]

I'd also leave the shades closed. I've always left blinds / curtains closed whenever we're not on the boat. If getting cold is a concern, it's more of an issue overnight anyway. Early and late in the season I tend to leave one of the reverse cycle A/C units running for heat so the boat stays warm if we get a cold night.

 

[koliver]

If not shaded, your upholstery will fade with exposure to UV rays. There is no doubt that will occur.

"One Way" depends on the brightness on each side of the glass. those on the bright side can't see what is on the dark side, while those on the dark side can see what is on both sides. Change the relative brightness and the "direction" of the one way reverses. In the context of reducing UV, "One way" is not helpful.

Fifertex acts to limit the amount of light passing through the shade. Some allow 5%, 10% or more. We have ~5% on the front windows and ~10% on the sides. The front covers have to come off to move the boat. The sides remain covered most of the time. These provide privacy and adequate cover to limit fading. There is no upholstery below the front windows, so no direct light onto the upholstery from that source.

 

[High Wire]

We leave our curtains closed. It will stay warm enough in the cabin from the warmed shades. The UV will eventually fade and destroy the shades so plan ahead.

 

[rgano]

I find that in winter weather here in the panhandle of Florida my 40-dollar Peltier effect dehumidifier sitting in the galley sink adds a bit of warmth to my downeast cabin.

 

[Hippocampus]

We will not be on the boat so as per protocol will leave all below waterline thru hulls closed. So no opportunity for AC and don’t care about inside temperatures. We are not there.
Have much experience leaving boat in the tropics. Up here in Hilton head temps do fall significantly during the night but it gets to light shirt weather during the day. Research shows similar weather for the period of our absence. It’s different than the tropics or New England hence the question. Humidity is modest so far will hang damp rid bags. Put out a few mildewcide bags and open lockers/drawers/engine room. Then call it a day.

Thanks for the replies.

 

[twistedtree]

I prefer shades down, but not blackout shades. You want to cut the UV, but the darker it is inside the more prone to mildew and mold.

 

[Hippocampus]

TT thank you for that. That addresses my particular question.

 

[Comodave]

Ventilation is key. On one boat I put a solar vent on the hatch in the forward cabin blowing into the boat. In the aft cabin shower I put another solar vent in the cabin side blowing out of the boat. Boat always smelled fresh and no mold or mildew. I would put the shades down too. Block out the UV. On that boat I made covers for the cabin windows out of white Stamoid. It would allow light into the cabin but block the UV. Also it is waterproof so it helped keep the windows from leaking.

 

[Hippocampus]

Surprised compared to sailboats who frequently ventilation is not optimal on small/medium sized trawlers. Nothing like a bunch of dorades with some facing forward and some aft to keep a boat ventilated and wind/spray out. My boat has none. Much prefer natural ventilation. No problem underway or at anchor. Open pilot house doors and aft salon door and great ventilation. But get none when buttoned up. So when leaving it for awhile better off to button up, dehumidify and either bomb it or leave a mildewcide hanging.
I’ve had nothing but bad luck with any solar vent as have my friends. Not a fan.
Although Edwin’s boat is a very excellent boat I noted the absence of natural ventilation. A dorade like device could be incorporated into the corners of the house without being very visible and not destroy the aesthetic he seems to want to achieve.

 

[twistedtree]

Ventilation is good, but not always, especially when unoccupied....


If you get situations where the interior is cold but it's warmer outside, venting in the outside air will likely lead to condensation. It all depends on the relative temperatures and humidity levels. I ran into this with an unheated boat in New England. The spring was bad on days when the outside temps warmed up, but the boat's core was still cold. Also in the hot humid part of the summer with humid air outside and lower parts of the hull cooler from the water. I expect it's different if there is a source of water in the boat, like a wet bilge. In that case not letting it accumulate inside makes sense.


I have run into this in basements in old houses. Common recommendations are to ventilate, but I have found that exactly the opposite works better, all because of condensation. Especially in the summer, outside air circulating through the basement condenses on the cooler basement walls, and you are effectively pumping water INTO the building. I got a much drier (lower humidity) basement by closing the windows rather than opening them.

 

[koliver]

Surprised compared to sailboats who frequently ventilation is not optimal on small/medium sized trawlers. Nothing like a bunch of dorades with some facing forward and some aft to keep a boat ventilated and wind/spray out. My boat has none.

Add some dorades.

 

[RT Firefly]

Greetings,
Mr. (Dr.) H. When we left our boat for extended periods of time both in NC and in FL we lowered blinds and left 110v oscillating fans running 24/7. There was no mechanism whereby we could readily ventilate (ports/dorades/solar vents so she was pretty well buttoned up. One or 2 fans in each area/room. I did NOT want to run the AC,

2 in v-berth, 2 in forward guest, 2 in master, 2 in saloon/galley and one each in ER and pilothouse. Never a problem with mold or smells even after 6+mos. You get funny looks when you buy a dozen fans at once. We probably cleared out the store's complete stock for the year.

I also think if you keep the air moving, even internally without inside/outside air exchange, it hinders mold development.

IF I would have had a dehumidifier I probably would have used that as well and drained to the galley sink.

 

[Hippocampus]

We’re back home now.

The shades are set up so first pull down is translucent but if to continue to pull down it’s opaque. Decided to pull down so Bottom half translucent and top half opaque. Snapped in the sun reflecting shades for the pilot house. They are done from the inside so no risk of them blowing away.
Took off all canvas except the cover for the dinghy and flybridge instruments . For the dinghy ran some line around it so no wind risk. For the flybridge dropping the Bimini frame and some short line should prevent wind issues.
We buttoned up the boat. Hung dehumidifier bags in all spaces including the engine room after mopping up the last drop of water in the bilge.
Just before leaving and locking up hung mildewcide bags. The gas released is heavier than air. So one in the pilot house. One in the master stateroom. And one in the salon. They’re good for 700sq.ft. so a bit of over kill. All lockers, closets, and drawers left cracked open. All internal doors left open.
Left no fans running nor our electric dehumidifiers nor AC. In fact other than battery chargers and such nothing but the bilge pumps are on. Although we are plugged into 2 30a lines wanted no loads that would exceed our solar production. Never saw a yard worker walk the docks even once so not confident we would be replugged in if needed. Fortunately got friendly with folks living on their sailboat who say they will keep an eye out.

Only downside is that when we return can’t occupy the boat for at least 6 hours until it airs out. To do this will open every exterior door and turn on the AC units briefly. Mold can grow in the ducts so once air goes through them turn them off and turn on the host of fans instead. Just hope it isn’t raining that day.

Thanks all.