Battery Box Gasket

[Chuck]

I replaced the battery box gasket, along with most of the other gaskets on the trailer a while back. I recently realized that the battery box compartment isn't water tight. A close look revealed that the gasket, which I mounted on the door, isn't touching the flange in the battery box frame in at least one area. (didn't take a pic, as I didn't think it would show up in a photo...can barely see it "in person").

I'm wondering if the gasket is supposed to mount on the trailer side, rather than on the door itself. All the other openings on the trailer use this same "U" shaped gasket..actually, the profile looks like an italicized "U", and its supposed to mount on the "hatch" side of the openings (be they windows or doors).
Its possible that the battery box got slightly bent or warped, but it doesn't look it. There's no obvious damage to it, so whatever warpage is so slight, I couldn't imaging trying to bend it back into shape. the door operates and closes fine. I'm wondering if some generic hardware store weather stripping on the frame would fill the gap enough to seal it.
any other ideas?

(this may explain why, when I had dropped the belly pan for an underside inspection, the heaviest rust/corrosion was just behind the battery box area; probably been leaking for a while).

[Chuck]

Ok, I took a closer look. its definately been "distorted"...bent in some fashion. It also seems a little bit more maleable than I thought it would be. if I press on the part that seems bowed out at the bottom, I can get the door to come closer to fitting...I'm thinking it would be adjustable using a rubber mallet to try and persuade it closer to its original shape.

I took a couple of pics...its hard to see, but if you look close, you can make out the gap where the gasket isn't even touching the frame. 1/8...maybe 3/16" gap there. no problem sliping a dollar bill in there with the door closed. Most of the way across the top edge, its not touching, although the left corner is the worst.

in the second pic, you can see that the top edge of the door isn't square with the door frame...and the trim doesn't line up. maybe it was bumped in a direction perpendicular to the trailer's wall, while the door was open, pushing it in. (just a guess...as the skin or face of the door doesn't look like its ever been damaged. )

any suggestions? I'm all ears....

[wahoonc]

Chuck,
My battery door is warped too. I wonder if it has anything to do with people sliding a 60+# battery back and forth on it? Mine does not have gaskets on it, and does not show evidence of ever having had them.

Aaron

[Chuck]

yeah, I suppose that would do it.

hard to believe there was never any gasket at all on yours....without something in there, it must be a bit of a rain-scooper.

[wahoonc]

Chuck,
It probably does catch rain, I will get a better handle on what goes on back there when I get that closet torn out. That should be coming up pretty soon...if I ever get home My battery area is completely encased in plastic and the door has a plastic interior cover on it. So maybe it didn't leak....much

Aaron

[Kistler]

My trailer has no gaskets on the battery compartments. I guess they were saving weight?????

[Frank S]

Hi--My battery box has a gasket installed by the PO. Could they have originally come with out a gasket for venting purposes, as the inside of the box appears to be sealed from the inside of the A/S?--Frank S

[wahoonc]

FWIW (and it ain't much ) my service manual shows a gasket on the door...but it shows a lot of other things that didn't happen either

Aaron

[Kistler]

Seems that the battery boxes are plastic; I think I like the fact they "vent" to the outside. Mine are under the divan.

Kistler

[GO Bob]

Battery box are NOT to be sealed. Batteries produce hydrogen gas and do nasty thing like go BOOM if alowed to be cofined. I had a sealed flash light that used only 2 AAA batteries. One day I changed the batteries and did not put the catalist pill , changes H2 to H2O, back in. The instruction clearly said "Danger check for catilist and do not use if not present". While in my pocket the light must have turned on because I heard a crack and felt something pop my leg. First thought was I was shot buy a 22. The light had exploded in two. that was 2 AAA batteries. Please do not seal your battery compartment. The plastic liner if in good shape will keep the water out of the trailer. This needs to ckecked at least yearly for cracks. When the battery leaks acid you do not want it in your trailer. If still wondering check the battery label about cofined spaces. If you want to see what hydrogen does I'll find some pitchers of the fire this year.

[Chuck]

You know, I was wondering about the "venting" thing. Maybe I should just leave well enough alone. But I'm not confident that the plastic box keep water out entirely. Its not a floor rot issue, as the box sits below the floor of the trailer, but water that gets in winds up sitting along the hinge of the door, and slowly works its way into the belly pan, soaking the underside of the frame and cross members.

A couple of years ago, when I had the belly pan down, I found that the heaviest corrosion on the frame was right in this area. Now, I also found that the frame around the battery box wasn't sealed well, and the wooden supports that fit up against the 2 outriggers that form the sides of the battery box were a couple of plywood sponges...soaking wet, and rotted. I cut new one's and replaced them, then sealed up the box frame with vulkem. maybe that's the only place water was getting in. But I don't know...I'll see if I can find the pic.

on edit: ok, here's the pic. this is curbside, facing aft. the battery box is just to the left of the cross member that has rotted through in one spot. maybe that was from the sponge oops I mean 'insulation' that the factory put there...but there it is. the pipe is the shower drain.

[Chuck]

I found the exploded diagram for the battery box in the service manual, and it does show a gasket on the door. The pic also jarred my memory...the battery cables come in through holes in the side of the box. the holes aren't sealed up at all, so the box would never be air-tight. The battery cables go through the holes, through the outrigger that forms the side of the box, into the cavity between the main frame channel and the bananna wrap. then they go up through 2 more holes in the plywood floor, into the closet in the aft corner of the trailer, where they connect to the univolt.

I can't remember if that banana wrap cavity in the corner was stuffed with insulation, or not. Even if it was, it wouldn't be "air tight"...but would inhibit air circulation a bit.

so I wonder if this is (or was) considered to be adequate ventilation for the battery??

the top of the battery box is just a plastic "half-a-box" that sits on top of the floor and is screwed down to it. if that were sealed around the edges, and the battery cable holes are sealed up w/ caulking, no gas could get into the living compartment of the trailer. there might be a build-up of gas inside the box, but it wouldn't be under pressure or anything, as it could leak out into the belly. But H2 would want to rise; not sink. so...
thoughts??

[GO Bob]

Sealing the box from the living area is the first and most important. besides the H2 batteries can produce sulfuric acid gases. As a gas it can be unplesant to deadly. Unlikely, but in a small inclosed space it would be worse. This acid can be seen as that white stuf on and around the battery. This oze or if a battery cracked would send acid through trailer.

Now. The battery box need to vent directly to the atmosphere. For the same reason the propane line is not under (between floor and pan) the belly pan. These hydrocarbons can rise and pool just waiting for an ignigtion sourse. Lead acid batteries are dangerous.

Please read the safety info from the battery manufactures. They know more and can explane it better.

[Chuck]

yes, I understand what the potential hazzards are. But this design is not something that I cobbled up in my back yard. it was designed and built this way by the airstream factory.

[GO Bob]

Some designs are bad ideas in practice. My '75 has a battery door like yours. My '82 has slits in them which is not perfic because being in the front road grime gets over the batteries.