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Message |
Barry McCully (Turtle)
Registered Member
Username: Turtle
Post Number: 10
Registered: 8-2007
Posted From: 71.7.213.91
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 18, 2008 - 5:00 am: | |
I had an earlier post about putting a roof air in one of my roof hatches and was told to make an alum. frame 14.25 x 14.25 which I did does anyone know what the proper way to continue would be what or I have to buy or to make. |
JR Lynch (Njt5047)
Registered Member
Username: Njt5047
Post Number: 210
Registered: 7-2006
Posted From: 70.61.104.58
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 18, 2008 - 10:43 am: | |
Drill out all the rivets, remove the hatch, frame and get the roof smooth around the hatch area.
Find the aluminum material you plan to use for the hatch cover. Some are using stainless steel. Aluminum will be easier to work with, and electrolysis is less a problem.
The AC frame should be welded inside the hatch frame...which is going to be a problem with your aluminum frame. Would redoing your frame in 1.5" mild steel be doable? Biasing the AC opening towards one end of the hatch will make building the frame easier. Let one hatch crossmember serve as the front, or rear support. I'd keep both ACs in the forward-most position. That would keep the driver cooler, and the rear AC will be further forward from the rear wall.
Keep the overall height of the new hatch cover roof material equal too, or a fraction higher than the surrounding bus roof. You don't want water pooling at the AC base. Maintaining the curve of the bus roof will almost be necessary for the hatch cover panel to lay flat against the roof. The AC gasket will easily accomodate the roof curve.
Once the frame is in place, the rest of the job consists of sealing and riveting the new roof panel in place. It isn't necessary that it be attached to the AC frame.
If you use any blind hole rivets, be sure to use "Cherry" rivets or something waterproof. I'd use sealer on the rivets too.
Sikaflex would make a permanent seal between the panels.
Other 'busnuts will have more (better) information.
This will give you something to think about.
Now Gitrdone! JR |
Camill Paul Elbisser (Paul)
Registered Member
Username: Paul
Post Number: 46
Registered: 3-2005
Posted From: 72.49.46.249
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 12:36 am: | |
I welded in 1 1/2" sq. steel tub and lined with 1 " wood to make a 13 3/4 opening for AC Units.
You can see this at www.incredibus.com
Good Bussin
Paul |
John MC9 (John_mc9)
Registered Member
Username: John_mc9
Post Number: 577
Registered: 7-2006
Posted From: 66.217.105.121
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 2:20 am: | |
Yikes!
If the ceiling of the bus is out, I guess having that 14.25" frame
pre-built will work out.... If the ceiling is still in, well..... It ain't
gonna' be easy squeezing that frame inside the hatch opening.
I (and many others), used 2" square oak stock, and simply
built the frame inside the hatch opening. The wood absorbs
a lot of vibration and is easy to work with.
The hatch must be removed, and the "lip" ground off the existing
frame. There's no real need to remove the entire hatch frame,
since the frame is solid enough to support further construction.
The new, smaller AC frame can then be built inside the existing
hatch frame, closing it down to the required 14.25" dimension.
You then have to cover the "new" opening with aluminum
stock, and cut a 14.25" hole to match your frame. The
aluminum should overlap the opening by a few inches at the
least! You should use butyl under the sheet of aluminum,
to prevent water from entering. Most of us have used
self-tapping sheet metal screws to fasten it down, since it makes
re-tightening (or re-caulking) the assembly in the future, possible.
Cheers! |
JR Lynch (Njt5047)
Registered Member
Username: Njt5047
Post Number: 211
Registered: 7-2006
Posted From: 70.61.104.58
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 10:54 am: | |
HELLO!...A clarification: I do not recommend removing the welded in steel hatch frame...nooooo, just the aluminum inner trim...that's a frame of sorts..isn't it?
Has anyone ever mounted an AC in the actual hatch? Reckon how strong a hatch is? This isn't a recommendation...just idle thought. Lots of 'idle' time right now. Snowed last week, it raining now, 37*, and snow for later. Can't play outside. Bummer.
Paul has posted several great AC frame photos.
http://www.incredibus.com/images/droproof/100_2584.jpg
JR
(Message edited by njt5047 on January 19, 2008) |
H3-40 (Ace)
Registered Member
Username: Ace
Post Number: 746
Registered: 10-2004
Posted From: 75.200.189.226
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 11:46 am: | |
FWIW, my ac's both front and rear were installed in the OE escape hatch. The one in the middle was installed in a self cut hole!
NO problems yet!
Ace |
JR Lynch (Njt5047)
Registered Member
Username: Njt5047
Post Number: 212
Registered: 7-2006
Posted From: 70.61.104.58
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 3:40 pm: | |
Hey Ace,
Seems like a good idea...if the hinges and seals are good. ACs aren't that heavy.
Or, if the hatch on an MC9 couldn't handle the job (I got no idea?), use the top of the hatch and build a lightweight frame for the AC.
FWIW, JR |
David (Davidinwilmnc)
Registered Member
Username: Davidinwilmnc
Post Number: 221
Registered: 7-2005
Posted From: 75.180.200.138
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 4:12 pm: | |
I'd mount an AC (heat pump, actually) in the front hatch if I had one (MC-8's didn't). I do like having my rear hatch available. It's how I get up there to paint or clean the roof. It's also how I got my front unit up to the roof. I'd definitely keep the rear hatch free to open.
David |
Jim Wilke (Jim Bob) (Pd41044039)
Registered Member
Username: Pd41044039
Post Number: 254
Registered: 2-2001
Posted From: 208.6.60.4
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 5:21 pm: | |
I "temporarily" mounted a roof air on the escape hatch on our '87 Eagle. IF your OEM vent/escape hatches are the same as the Eagle (and I think most are) then do not waste your time. Here's what I encountered:
The removeable hatch and it's rim are made of plastic. I originally thought "no problem, they won't rust or leak." So I took off the hatch & took it in the shop. I cut a 14.25" hole in it only to find out that the hatch is two thin pieces (1/8") of ABS glued together with a hollow area about 5/8 inch in between. So being more stubborn than smart, I did sume surgery and inserted a piece of plywood between the halves to give it some strength.
So I put the hatch back on it's frame and went to mount the AC on it. Now I discover that the hatch lip is raised about 2" above the roof. So some sort of block has to be fabricated for the rear half of the AC to sit on. (It usually sits on the hole AND on the roof with foam blocks.) You may think you can skip this part but the AC is heavy enough to hold the front of the hatch open just enough for rain to get in.
Next, after you cheat the roof god & get this AC mounted in the hatch, we find that the inside cover/ducting won't fit AND the wiring doesn't work the way it's supposed to.
So I surmounted all of these issues about 2 years ago only to find out this fall that the designed life span of the ABS hatch rim has expired and cracks are appearing from the outside perimeter to the rivet heads that fasten it down. (Now, before you say that this has something to do with what I did, you need to know that the other hatch which is factory stone stock with no AC is in identical condition!)
So, based on the above, I can say that not only should you not mount AC units on the plastic, but you should remove the escape hatch itself and replace it with something decent (like a boat hatch) or at least install new hatches.
BTW, I discovered the hatch rims were failing because of the water leaks INSIDE the Eagle which were traced to the hatches.
There, that's my $.02 worth. |
John MC9 (John_mc9)
Registered Member
Username: John_mc9
Post Number: 579
Registered: 7-2006
Posted From: 66.217.103.104
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 19, 2008 - 11:04 pm: | |
This part has got to be emphasized:
"So I put the hatch back on it's frame and went to mount the AC on it. Now I discover that the hatch lip is raised about 2" above the roof. So some sort of block has to be fabricated for the rear half of the AC to sit on. (It usually sits on the hole AND on the roof with foam blocks.) You may think you can skip this part but the AC is heavy enough to hold the front of the hatch open just enough for rain to get in.
Next, after you cheat the roof god & get this AC mounted in the hatch, we find that the inside cover/ducting won't fit AND the wiring doesn't work the way it's supposed to. "
It'll be the same scenario for the MC9! Don't waste your time.
Remove the hatch door, build a frame to fit, and be real happy! |
H3-40 (Ace)
Registered Member
Username: Ace
Post Number: 748
Registered: 10-2004
Posted From: 75.201.171.131
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, January 20, 2008 - 10:39 am: | |
UH maybe yours are different than mine! My complete hatch was removed frame, trim and whatever else there is to it. The ac was then installed as if you cut your own hole! There is NO frame built purposely for the ac unit and they sit flush on the roof and they DO NOT leak!!
Oh wait... this IS a Prevost isn't it, not an MCI or Eagle? LOL just kidding
Ace |