looking for recommendations for solar vents

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Sep 26, 2010
808
Macgregor 1993 26S Houston
Now that it's really hot outside I'm concerned about the temps inside my boat when it's all closed up. I looked at WM's website and they do have a couple of solar powered vent/fans, but I don't know if they really move the air.
It's hard to tell from the reviews.
??????
Jim

I searched the forum and it seems there isn't much to choose from.
They all look like their designed to be mounted horizontally to keep water out, but I see most guys install them in hatches. Is it safe t assume that most or some of these are sloped like the hatch on my 26s? That's where I pictured putting mine.
Jim
 
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Sep 25, 2008
961
Macgregor & Island Packet VENTURE 25 & IP-38 NORTH EAST, MD
Hi, I would recommend the 4" Nicro solar vent. I would guess most people install in a hatch so they don't have to cut a 4" hole in their deck. I wanted my vent to be close to the center of the boat, in an area where there is less 'foot trafic', and where it wouldn't interfere with any running rigging. With these factors in mind, I installed mine on the deck, on the port side, even with the mast. The deck is cored here, so i made the hole slightly larger and then epoxied over the exposed plywood to seal it off. The fan moves enough air to keep the inside vented well, but in no way does it create a draft (you can barely feel the air moving). It also keeps the inside vented during winter storage (providing you don't cover it up). The installation directions allow for it to be mounted on a SLIGHTLY curved surface, but its not much, a flat surface would be best. Also, consider what it would be like opening the hatch with one attached to it. On my boat the hatch opens all the way against the deck and if a vent was attached to it, it would get smacked against the deck every time the hatch was opened. Another good point for the Nicro vent is their warranty, its 2yrs. I had one that quit after 18 months and they replaced it, shipping included!
 
Jul 7, 2004
8,481
Hunter 30T Cheney, KS
This is on my list of things to do. The forward hatch is a popular place, not sure it's the best. I don't think the little bit of slope is a problem. Someone here installed one over the head - could be a diet problem :)
Solar is nice. If you have a steady breeze you might consider a wind driven fan, they are cheaper. I want one somewhere over the cabin area and one on the laz. I have the IdaSailor post riser on my tiller so clearance isn't a problem.
 
Sep 5, 2007
689
MacGregor 26X Rochester
Unless you're moving a lot of air, this kind of ventilation won't make any difference in the interior temperature. They do have value in exchanging the air to keep odors and possibly moisture from building up, but when the boat is baking in the sun, a few cfm won't make a discernable difference in air temperature. Far too much radiant heat bouncing around in there.
 
Sep 26, 2010
808
Macgregor 1993 26S Houston
thanks guys,
I ordered the bigger one from WM in stainless. It's rated at 1000 cu.ft./hr.
No telling how much it'll do in real life.
I originally planned on putting it on the hatch, but now that you brought it up,
the hatch is hard enough to open already, and the kids habitually open it up all the way and drop it on the deck. :(
I suppose I could install one of those gas charged struts to help open it and also limit how far it goes.
Over the head or galley seems like a technically better place but I'm not ready to cut a big hole up there yet. Maybe in a few years?
 
Jul 7, 2004
8,481
Hunter 30T Cheney, KS
Unless you're moving a lot of air, this kind of ventilation won't make any difference in the interior temperature. They do have value in exchanging the air to keep odors and possibly moisture from building up, but when the boat is baking in the sun, a few cfm won't make a discernable difference in air temperature. Far too much radiant heat bouncing around in there.
I agree. I found in our 100-plus degree summers that a tarp over the boom keeps a lot of the sun load off of the deck and in the cabin. We run AC fans below to really move air around when we are in the slip. A bimini is a necessity out on the water!
 
Sep 26, 2010
808
Macgregor 1993 26S Houston
I agree. I found in our 100-plus degree summers that a tarp over the boom keeps a lot of the sun load off of the deck and in the cabin. We run AC fans below to really move air around when we are in the slip. A bimini is a necessity out on the water!
Mine sits on a trailer in a driveway. Problem is that I don't live there so I always lock up the cabin. That cuts down on the ventilation. I know I should put a tarp over it, and keep meaning to but so far haven't done it.
I put the mast up if I think it's going to be there a while before I use it.
(It's harder to steal with the mast up!) But the boom stays inside. I guess I could run a rope from the mast to the stern rail or mast crutch.
Anyhow I was hoping it would lower the inside temp a little, and pull out moisture to cut down on mold/mildew.
Hope I didn't waste my money?
Jim
 

Faris

.
Apr 20, 2011
232
Catalina 27 San Juan Islands
If you're just wanting ventilation while the boat sits unattended, you really don't have to move a lot of air. You just want to move air constantly or regularly. Moving more air or moving it faster really won't do much more to mitigate mold/mildew problems. The best thing you can do is remove all cushions and open all compartments, then allow some air to circulate on an ongoing basis. And, don't leave standing water anywhere.

The rest will pretty much take care of itself.

And, moving air, even just a little, will lower the inside temperature while the boat is in direct sunlight. Moving more air will lower it more, but only to a point somewhere above the outside air temperature of course, but temperature is not your #1 enemy in the mold/mildew battle - it is moisture.
 
Sep 26, 2010
808
Macgregor 1993 26S Houston
Well $%^&&*#!,
The places where the shrouds attach to the hull have leaked ever since I bought it.
I haven't fixed it yet cause it's been so dry.
It's been raining some in the afternoons here lately, and while working on wiring the auto pilot last weekend I saw about an inch of water under the stbd settee. I thought If I just let the boat breathe it would take care of itself.
Sounds like tomorrow after work I need to get over there with a sponge.
It's always something.
I have some 5200 coming with the air vent on Friday. I can seal up the shroud anchors and stop it.
Thanks for the motivation guys!
Jim
 

Sumner

.
Jan 31, 2009
5,254
Macgregor & Endeavour 26S and 37 Utah's Canyon Country
....I have some 5200 coming with the air vent on Friday. I can seal up the shroud anchors and stop it.
Thanks for the motivation guys!
Jim
Be real sure you want to use the 5200, because all that I've heard about it is you aren't going to get things apart once you put it on. Some places might be the right application, but I wouldn't use it on the chain plates.

Our boat always got water after it rained from the chain plates on the shrouds and from around a port side window. Last fall when we were leaving the boat in Florida over the winter on the trailer in the storage yard I worried that we would come back in the spring to a boat that had water and mold.

I had some 5200 and 4200 and some 4000 on board and when we took the boat out I quickly put some 4000 around the chain plates without taking them off and also around the window. We came back 3 months later to a dry boat and neither leaked on the next trip when it rained and the seal still looks good.

I like being able to take things back apart and would rather have to put the 4000 or something else on a little more often vs. dealing with the 5200 after all that I've read about it.

3M™ Marine Adhesive/Sealant Fast Cure 4000 UV




[click to enlarge]
A high quality cosmetic sealant cures to form a firm, rubbery, water-tight seal. Superior UV resistance. Very low odor. Remains flexible.
http://solutions.3m.com/wps/portal/...E3E02LECIE20S4K7_nid=GW4D41NSGBbeQH8HT14PGTgl

I like the fast cure and the flexible part for the chain plates on the shrouds,

Sum

Our Endeavour 37

Our Trips to Utah, Idaho, Canada, Florida

Our MacGregor S Pages

Mac-Venture Links
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
I would not use 5200 on the chain plates.

once the mast is up, the (MY) plates move a bit with with the shroud. I did use well nuts to replace the rivits and reseal it w/ lifecalk around 1x / yr.

on the solar vents and tent. the PO put one on the laz hatch and on on the v berth hatch. they are ok. but both have died in the 5 yrs I owned it (probably a battery).

they didn't stop mold and mildue in SoFla, but may have worked in Tx where the PO lived...

I put a 20x12 silver tarp over the mast tied to trl and it covers the sides pretty well. thats what I'd recommend. (I have a 110v, fan running 24/7 and that keeps mold away)

or get one of the garage tents and lift it up with some pipe...
 
Sep 26, 2010
808
Macgregor 1993 26S Houston
I just picked the 5200 quick dry, because it said it's waterproof. I didn't know it wouldn't be flexible enough. I also didn't plan on taking the chain plates out. I was just going to try sealing from the outside for now. (I have enough projects!) Maybe I'll pick up some of that 4000 stuff.
I have one of those garage tents from Academy over my Hobie and it works ok.
The Mac seems kinda big for it.
I'm past due for getting in the water, I may forgo the vent install this weekend and go sailing. I haven't been for so long I can't remember how many weeks.4-5? Too many!
Jim
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
5200 is pretty flexible but its very hard to get off, and I think it will tear if you put the mast up and down. if you left the mast up, then it will probably be ok. but I like to reseal it, since the chain plate does seem to move when the shrouds are under load.

my old house and the garage tent lifted up... didn't cover entire boat (20') but covered the bow hatch to mid cockpit.



note: I have my mast raised up on the trl, so you may not need to go too high to get boat under it...

GL!
 
Apr 30, 2006
610
Macgregor 26s Kemah, TX
My old boat was kept in a slip. There was a lot of mildew if it wasn't vented. I think it was caused mostly by the temperature difference between the water and air causing condensation.

My Mac is kept on its trailer so the condensation problem is greatly reduced anyway.

In this area, the prevailing winds are southeast, and I use the wind to vent the boat, which faces west on the trailer.

I put a flat piece of rubber down when I close the forward hatch. This keeps the hatch slightly open but not so much that rain gets in. The main hatch has a natural gap in it and the wind blows through the main hatch and out the forward hatch enough that it stays ventilated. As someone said in an earlier post, it doesn't take a lot of air to ventilate the boat. Also, I roll up a piece of insect screening into the main hatch to keep the mud daubers out.
 
Sep 1, 2005
22
- - Annapolis
doehunter said:
Now that it's really hot outside I'm concerned about the temps inside my boat when it's all closed up. I looked at WM's website and they do have a couple of solar powered vent/fans, but I don't know if they really move the air.
It's hard to tell from the reviews.
??????
Jim

I searched the forum and it seems there isn't much to choose from.
They all look like their designed to be mounted horizontally to keep water out, but I see most guys install them in hatches. Is it safe t assume that most or some of these are sloped like the hatch on my 26s? That's where I pictured putting mine.
Jim
Another idea is to get PortVisors over your ports. I have them on 2 of my boat's 4 ports, and now I just leave those ports open most of the time during summer. Some rain gets in sometimes, but it's so hot and it rains so infrequently that I don't worry about it.

Just an idea.

Chris
 
Sep 26, 2010
808
Macgregor 1993 26S Houston
5200 is pretty flexible but its very hard to get off, and I think it will tear if you put the mast up and down. if you left the mast up, then it will probably be ok. but I like to reseal it, since the chain plate does seem to move when the shrouds are under load.

my old house and the garage tent lifted up... didn't cover entire boat (20') but covered the bow hatch to mid cockpit.



note: I have my mast raised up on the trl, so you may not need to go too high to get boat under it...

GL!
Looks like you have the mast high enough to raise the pop top.
I like that. The tent thing looks similar to the one I have over my Hobie.
I don't remember how tall it was but as you said I could raise it if needed.
I think it's 10 x 20 ft, so it would cover the cabin. Hmmmm
What's another 100$$ huh?
The admiral is already getting edgy! I gotta stop for a while.
 
May 4, 2005
4,062
Macgregor 26d Ft Lauderdale, Fl
I got my garage tent for around $99 at northern tool. added 6 pipes ~ 5' (?) tall, from HD, and drilled them for a stop, and inserted the factory poles in the over sized ones from HD. probably $40 total. then redrilled the pipes to anchor the top tubes in the bottom so it doesn't take off in a blow.

and yes rasing the mast allowed me to dry camp and work on the boat... and with the tent almost fun to work on it.

I got about 6 mo's out of the factory white canopy, and around 4 mo from the silver/blue tarps. ~ $25/tarp.

I ended up not dry camping, but thought I would..

I think I cut the 10' pipes in half but don't remember... think I used 3/4" emt.

*(and tent is a 10x20, tarp is ~12x20)

[10' 3/4 pipe = ~$4.25 at HD]
 
Jun 3, 2004
1,863
Macgregor 25 So. Cal.
You could just use some 2x4 to make a fake boom and another from the mast fwd to the bow and cover with blue/sliver tarp (silver side out) helps reflect the sun best.

Keeps sun and rain off the boat and you can even leave the hatches open a little by slipping a small block of wood in between the stops and still dogging the hatch.

I have an inverted cover over the companion way hatch that allows for ventalation with it secured [plus a lot of air leaks around the top.
 
Jun 5, 2004
997
Macgregor 26D Boise
I have had a solar vent in the deck over my head area for over 5 years. It works great to remove odors and ventilate moisture.
 
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