Roof AC removal

[OUTRIGGER]

I purchased a 22 (high top) with a roof AC installed. I want to remove it and would like any suggestions on what to do with the 14" by 14" hole.
I have looked at hatches and looks like I would have to cut out the hole even bigger, and the high top roof has a curve so don't even know if a hatch would fit well.
I was thinking about just a flexable plexiglass sealed down with liquid nails. Any thoughts about something better, or neater would be great.
Thanks

[Captains Cat]

First of all, living in Texas, most are trying to put AC in not take it out. Is it non-functional?

Guess I'd re-fiberglass it. Glass in the inside, lay in core material (probably got balsa in the surrounding roof and then glass over the top. Fairly straightforward, I'm sure Dr. Bob on Thataway could lead you through it.

To get started, put some plastic or other material that will release the fiberglass on the inside with tape.

Support it with a flexible piece of masonite or thin plywood. Lay glass cloth into the hole from the top, saturate with epoxy (if you chose to use that) or polyester resin (if you don't).

Let that set up.

Repeat several times making sure you cover the surrounding core in the hole.

Once this sets up hard, remove the plastic and masonite or plywood on the inside. Don't worry about the inside finish yet.

Put in the core material and repeat the fiberglass over the top of the core until you get up to the thickness of the roof.

Finish the outside and inside to match the surrounding fiberglass. If you live near a good fiberglass shop, I'd take it there.

Or, buy a new AC unit.

Charlie

[thataway]

When repairing a "hole" in cored material, it is more difficult than just glueing in a piece. Any fiberglass needs to be tapered at least 6 to 1, and then the new glass worked into the old over that taper. This needs to be done on both the top and bottom. You could make a plug, and them tape around the edges. The plug would be molded to match the curve of the top, and then glass mat and cloth used to tab in the plug, with the taper.

You could also build a top which is flat and level, as I did on the Tom Cat with the cutout--then use that flange for a piece of Plexiglass or Lexan. I have laid on large windows on a pilot house, using structural silicone adhesive. (It is not just your normal silicone or liquid nails)--the Plexiglass (acrylic) or Lexan (Polycarbonate) has a different co-effecient of expansion than fiberglass, thus the holes in it have to be large enough to allow for this expansion, and plastic "buttons" act as washers between the screw and clear material. You could do this with a dome shape, but the clear material would not be as thick or strong.

You can also put a wooden filler frame on top which follows the contour on the bottom of the frame, and flat on the top, and then use a 12" x 12" marine hatch, or even use one of the RV 14" x 14" hatches in this cut out.

However, I have cautioned about cutting out the top of any of the C Dories, without making a frame and then a level area over the top to install the RV air conditioner unit to give adequate support to the roof of the boat, and give a level surface for the air conditioner to sit on. See below:

[jennykatz]

This is one of the reasons for just using KISS system with window air from frigidaire $89 5000 btu .I would follow Dr Bob's recommendations for sure Good Luck

[Will-C]

I looked at different ways to get AC on our boat. I liked the roof line with out a roof top ac unit. But I didn't want another thru hull so I opted for a roof top unit. I would not be with out it. I saved the piece that was cut out of the roof if we ever sell the boat. We have trailered our boat from Maine to Florida and have used our roof mounted AC unit with a Honda EU 2000 generator and shore power just about everywhere. I keep the boat plugged into power at the house and turn on the AC when working inside the boat in our drive way. For me carring around an ac unit and having to stuff it in the window would be a pain in the butt. Besides in my opinion it l looks so ghetto. I like just turning the knob. I'm afraid to turn past low cool as it will get like a meat locker in short order. The roof tops cost a little more but for us we would not be without it. If I lived in Texas I'd get a replacement AC unit stuffed in the hole in your roof and have a place to escape the heat and sleep in comfort.
D.D.

[thataway]

To Second what D.D. said. We leave the air conditioner running all of the time durng the hot season (5-6 months a year in Pensacola, FL.). It prevents mold, keeps the cabin cool, and certainly is better for the inside of the boat. There is a real advantage to the RV type of AC unit, without the thru hull and cooling water system. All of the small Corp of Engineer boats and many of the smaller tug boats use the RV type of Air conditioners on the wheel house or pilot house. The RV air conditioners seem to last longer than marine units and are far cheaper and easier to replace if it becomes necessary.

[jennykatz]

Outrigger if unit is still working just keep it .If we went on extended trips like DD or dr Bob I would have considered roof A/C but for mostly day trips and occasional marina trip the window model works for us . The only problem with roof air on cd22 high top is its looks but if you can get over that just keep it . On the other hand if the unit is broken or just doing day trips just follow Dr. Bob's discussion and recomendations he has done this already

[OUTRIGGER]

Thank you for all the great info & help. I think y'all want to know why I would remove the AC if it still works. I envy those of you who take days or weeks trips and an AC would be necessary. I also love all the pictures of your C-Dorys on nice smooth waters. But this is my situation. My 22 is in a small subdivision marina on a relatively small lake. We only go out for sunsets and to restaurants. Our house is just a block from the marina. We will never sleep on the boat, even have taken off the pottie since it would never be used. The marina only has a 15 amp breaker for around 20 slips. Even when a couple of battery chargers come on at the same time the breaker pops. So I would have problems plugging in a 15 amp AC. So no using the AC at the marina.

I do have a small Honda generator which would power the AC. but I don't want to mess with taking it to the boat & back (it would walk away if on the boat). Also don't really want the noise. Our lake does have a lot of wave & wake action, to that 100 pounds up high makes the boat bob side to side more than normal.
So there you have it. Maybe years from now I will be retired and able to trailer and do some real trips, but for now the AC won't be used.

[Minnow]

Getting back on the original topic, those pictures sure look like that roof is cored, but the roof on my 25 is not cored in the middle. Only on the lower sides of the roof and the short flat spot just behind the brow.
Was there a change in roof construction, or is it model specific?

[Sea Wolf]

[Les Lampman]

To the best of my knowledge the center (popped up) section of cabin top on the CD22 was never cored.

Sometime about 2005 and later (subject to verification) the side sections of the cabin top (that is, to either side of the popped up section) got a layer of coring added to the inside to facilitate mounting the cabin lights.

Les

[thekurp]

[wailedcentipede]

getting of topic .. your house air may not stay on 72 but at a minumum with air the inside temp should be 10 degrees lower than outside .. on the sunny side pull the curtains that helps .. the odd day were in the high nineties our inside temp is 20 degrees cooler than outside depends on the number of times the doors are opened .. wc

[cruiserlessvinny]

Or. Your supply air (blowing out of the register) should be, depending on many factors and who you ask, 13-18 degrees cooler than your return (air being sucked back into the duct) air. It is not advised that you turn your a/c on if the outside temp is less than 65 degrees.
CV