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wacnstac · 06-08-2006, 06:28 PM

I know there is a lot of threads about this and I have read them all. One place I think mice are getting into my trailer (31' rear bath 1979 International) is along the main electrical cord (have already blown the expanding foam around this) and I think the rear frame openings I have seen references to. Problem is I don't exactly see where these are or know where to look. Do you have to remove the rear bumper to get at these and fill them in?

66Overlander · 06-08-2006, 07:37 PM

wacnstac,
I think it depends on what type or rear bumper you have. Many 70's - 90's Airstream trailers have an opening compartment at the rear bumper, where the lid is hinged upward. These trailers typically have a aluminum (I beleive) bumper bolted to the frame ends. If you feel behind this bumper you will notice that the fame ends are open. Also, if you look in the bumper storage compartment, there are large (maybe 4" dia.) round holes going into the inner side of the frame rails. If this is the type of rear end your trailer has this will be obvious:

I do know, however, that some Airstream Trailers (at least from the late 80's & 90's) have an integrated rear bumper where the lower rub strip wraps right around past the rear of the body around the rear bumper. In these trailers there may or may not be a pull out drawer storage compart as part of the rear bumper. I haven't looked closely at these trailers, but it may be that the frame ends are not exposed and so there may be no opening for mice or other critters to enter

And I should note that there are a few late 70's trailers (just the Excella 500 model as far as I can tell) that have a separate (I think aluminum) rear bumper but have the belly pan/skirting extended to close out at the bumper. I think this also enclosed the frame ends. This one also likely does not that the rear frame ends exposed. I am guessing this this is what you probably have:

I attached the best photo's of the three rear bumper types I could find. I hope this helps.

wacnstac · 06-08-2006, 09:04 PM

My rear end looks most like your first picture.

wacnstac · 06-08-2006, 09:13 PM

In fact here is a picture of mine:

Seems like another big potential entry point is in through gap around black/grey drain tube. Not sure where that gap will take them as it is sort of hidden by the black plastic box back there for storage of dump hose and electrical cord. Don't know how you get to the ends of the frame in this configuration as they also seem to be sort of hidden on the inside by the black plastic storage box.

wacnstac · 06-08-2006, 09:14 PM

Second try at the picture:

66Overlander · 06-08-2006, 09:38 PM

To check if your frame ends are "open", just feel along the back side of the bumper going toward the frame rail. I suspect you will find that the frame ends were cut "vertical" (i.e. straight up), but the bumper has a curved contour, thus leaving an opening for critters to get in.

It looks like the dump pipe coming thru your left frame rail may restrict entry into the bellypan, but it may not stop mice who can wiggle thru tiny spaces. I'll bet the right frame rail would be like a superhighway for mice, however, without that drain pipe.

I have two superhighway's because my dump valve is further forward on our trailer.

CHANGING SUBJECTS SLIGHTY:
I've got to say I have been concerned about moisture getting into the rear frame rails and rusting things out from the inside. I look in the round holes into the frame rails in the rear storage compartment after a rain and the insides of the frame rails are often wet. It seems that is is impossible to keep the water that runs down the rear of the trailer from entering this rear storage compartment. I've tried gaskets and caulking with no success unless I want to seal this compartment permanently (which I don't). Some of this water must be going thru the big round holes into the frame rails. I wonder if I used your idea of expanding foam if I could at least keep the water that does get into the frame rails from running forward into the body of the trailer (and eventually out the bellypan somewhere). I could make a foam barrier just forward of the big round holes. I guess I could foam over the big round holes, too, if I wished. Or would blocking the interior of the frame rails somehow decrease ventilation of the bellypan and cause other problems?

wacnstac · 06-08-2006, 09:44 PM

I don't know but it seems like the whole back pan area of this model is a bad design. It is also very prone to leaks of water coming back in from on top and from below the piece of aluminum that extends from storage door and runs under the molding in the back. I'm not sure I have that problem solved yet either.

66Overlander · 06-08-2006, 09:50 PM

I just reread your reply. I beleive you are right in that the black plastic liner in your rear compartment may be hiding the "big round holes" I mentioned. In fact your drain pipe is probably going thru that hole in your left frame rail. I can't remember if the liner blocks the hole in the rignt frame rail or not, but it may. If you pry it back a little bit you may see the big hole I was mentioning. Trailers without the rear dump valve (like ours) do no have any such liner. I guess the best way to see into the frame ends in your case would be to remove the bumper. To do so takes a very large phillip's screw driver. There is one screw in the top and bottom surface of the bumper into each frame rail (4 total). If you take the bumper off, the liner will probably slide right out to give you a good view of what's back there.

I have been toying with the idea of taking our bumper off to paint the inside of the rear section of the frame rails to slow down rust formation due to the water that gets in there when it rains. I wonder where I can find a huge phillips screw driver?

wacnstac · 06-09-2006, 06:20 AM

I was thinking about dropping the pan just enough in the very rear section to see what is going on. Is this a possiblity?

enduroryda · 06-09-2006, 07:16 AM

Mine is the second one in the above pics..although there really isn't a spot for mice to enter the bumper I agree with wacnstac about the water in the rear pan area. Check out the pics I have included to the left and right areas of the water heater...no sealent or anything in there and it looks like a nice little drain area right off the sides of the heater. It might almost be benefical to drill a few drain holes at the lowest point. I know water is deff getting in there because when I was working on my wheel wells there was water and mud collected in that area.

nickcrowhurst · 06-09-2006, 10:00 AM

Quote:

Originally Posted by 66Overlander

I have been toying with the idea of taking our bumper off to paint the inside of the rear section of the frame rails to slow down rust formation due to the water that gets in there when it rains. I wonder where I can find a huge phillips screw driver?

I've done this job on two airstreams, and, on both, the setscrews had corroded into place, probably due to electrolytic action with the adjacent dissimilar metals. I had to drill the heads off, remove the bumper, and then centre punch, drill and tap the holes for new setscrews from my Airstream dealer. I re-installed them with anti-sieze, after de-rusting the area, coating with phosphoric acid and painting the accessible parts. I then used anti-corrosion fluid with a 25 foot long tube to spray the whole of the insides of the box sections. This is described in detail at
http://www.airforums.com/forum...-rot-2607.html?
Nick.

wacnstac · 06-09-2006, 10:46 AM

The link you posted does not take me to the thread you describe. Just how big are the heads on those phillips screws?

nickcrowhurst · 06-09-2006, 11:43 AM

Sorry about that. The system is truncating the URL each time I try. I'll keep trying.
The cross-point headed setscrews have a head diameter of about three quarters of an inch, and they are about 2 inches long, IIRC.
Nick.

nickcrowhurst · 06-09-2006, 11:58 AM

I can't get past this URL problem, but you can get to two relevant threads by using the search facility on:

corrosion chromate rear bumper nick

and

frame rot bellypan listing

Nick.

Jim & Susan · 06-09-2006, 12:04 PM

http://www.airforums.com/forum...?highlight=rot

Is this the one?

Jim & Susan · 06-09-2006, 12:10 PM

That's strange, it shows up on the "reply" page, but then gets screwy when you hit send.

I agree Nick about the problems taking that bumper area apart. Those big screws were a pain to get out. Luckily 3 of the 4 did eventually come out, so I only had to sacrifice one to the Bumper Gods. So you were able to get exact duplicates direct form Airstream, another bit of good news. Thanks for the info.

Now, let's see if we can whip the link problem......see if this works:

http://www.airforums.com/forums/20375-post5.html

Yep, this works. Click on this link, then when it opens, click the upper right hand corner to see the entire thread. Great thread, Nick, BTW.

Jim

wacnstac · 06-09-2006, 12:46 PM

Supposedly my rear bumper was recently removed by a dealer who rebuilt my dump valves. Perhaps this will make it easier for me to take off. Don't know where I'll find a driver that big though. When I take this off I assume I'll be able to clearly see where my main dump pipe enters the underbody/inside of my trailer as well as the end of the frame rails.

wacnstac · 06-09-2006, 08:04 PM

Where does one find a phillips driver that big?

nickcrowhurst · 06-09-2006, 10:53 PM

Steve, although the heads are large, the slots on mine did not go right across the heads, and my largest screwdriver fitted OK. My manual impact driver also has a large cross-point bit. BTW, how's the furnace repair going?
Nick.

66Overlander · 06-09-2006, 11:07 PM

Quote:

Originally Posted by enduroryda

Check out the pics I have included to the left and right areas of the water heater...no sealent or anything in there and it looks like a nice little drain area right off the sides of the heater. It might almost be benefical to drill a few drain holes at the lowest point. I know water is deff getting in there because when I was working on my wheel wells there was water and mud collected in that area.

I have caulked the top edge of the lower rub strip around the entire perimter of my trailer. I have caulked the little gaps you show near the Water Heater where the belly pan wraps over the side panel, as well as caulking around the Water Heater itself. I have caulked across the top of the rear bumper closeout panel. I have caulked around all lights and other things attached to the side panels. And I still get water leaking out of the bellypan when it rains. It mostly leaks out where the frame protrudes from the bellypan for the rear bumper and for the axles. I am still guessing that most of it is getting in there via the rear frame ends.