How to close belly skin gap? See photo...

[Zstream]

I have 4 large gaps in the belly skin at each corner. This is where the skin should butt up against the frame. I have attached a photo of the gap pictured from the right rear (belly skin is removed at the left under rear cargo area.)

Is this gap an anomaly or do most older models have this issue? How can I seal up this area? Was thinking of riveting in a long strip of aluminum and then using caulk to seal. Hope to hear from other that have successfully closed this area. Tks. Z.

[Jim & Susan]

Good question. I can't decide what to do with mine either. Maybe a chunk of aluminum cut to fit and lots of Vulkem.

Jim

[markdoane]

I riveted a length of 1/2" aluminum angle to the frame, and riveted the belly skin to that. The gap on mine wasn't as wide as yours.

[62overlander]

looks like dejevu to me... I have that same gap.... I think of it as the escape door for the mice after they eat some of the delicious decon I feed them. However Marks idea of angle is a good one. Wish I had thought of that before I bucked it all into place.

[davidz71]

I understand the reasoning for closing the gap, to keep some critters from gaining access to the trailer. I question sealing the pan against the frame with caulk. I have found that in a couple areas where the belly pan is sealed with what was once white caulk/sealer, the frame is pitted from rust. I have wire brushed those areas, applied degreaser, zinc phosphate, POR15 and POR15 Topcote. It would seem to me that you would want the belly pan to breathe to get rid of moisture instead of caulking it up.

I'd just rivet a piece of aluminum to the belly pan so that it is close to the frame.

[87MH]

Below is what I did when reinstalling the belly pan of the '78 31' Sovereign

1" X 1/8" aluminum strips are held in place with Stainless machine screws.




Below are the repairs and supports in the area of the step.



A material I used with great sucess for sealing the underbelly was found at NAPA (automotive parts). The product is listed in NAPA books as "evaporator insulation tape". It is a black mastic sold for sealing the area of the AC/Heater Plenum where the AC lines and the Heater lines enter and exit. It is also used by Home AC techs for sealing the same area and filling in larger gaps in the AC/Heater duct system. It comes in rolls about 3/16" thick and about 2" wide - not cheap, but it seals great and is extremely workable. There is no sign of it drying out after two years - still pliable. I worked it into any place I could find that might provide an entrance point for small uninvited guests.

The rivetting of the aluminum angle to vertical supports mentioned earlier in this thread is also a great hint. Shorter sticks of aluminum angle are available at most hardware stores and big box home centers. Not the cheapest way to buy it, but usually available when you need it.

I agree with craig's (davidz71) comment about (not) fully sealing the belly pan - I still have plenty of "breathing" gaps - definitely rust proof anything you can prior to replacing the belly pan.

[davidz71]

87MH,
I noticed the outrigger holding the left hand side of your steps looks to have surface rust on it. I had noticed both of the outriggers supporting my steps had some rust on them and the frame between them was getting badly pitted. I realized that this area is open all the time to the elements so I drilled out the rivets around that belly pan area, cleaned and did the POR treatment mentioned in my post above. I even treated the galvanized sheeting under the floor area as you look up by the steps. After the POR and subsequent Topcote cured, I buttoned the belly pan up. I feel that the area is now better protected.