underbelly sheetmetal coming off

[jerry]

Just got back from short weekend trip and while returning home our friends behind us noticed some insulation fall from underneath my bird. I stopped and found one strip of sheetmetal peeling back allowing the insulation to blow out. I noticed several screws either gone or coming out.
Does anyone know of a good way to put in new sheetmetal screws and make them stay. Not long ago I got under the bird and tightened up every screw that appeared to be coming loose. Most of these screws do not screw into anything solid, just the other piece of sheetmetal.

Thanks, Jerry

2006 Cardinal 30WBLE
2003 Ford PS

[Future Fulltimers]

Try putting some calking around each hole and on the screw threads before reinstalling the screw. This should keep the screw from vibrating loose. I would use silicone since it will stick to just about anything.

[Tim]

Also recommend you go up one sheet metal screw size when you make the repairs.

[Olbird]

Jerry,
They make screws with serrated heads that grip into the sheet metal like a locking star washer does but its made onto the screw.
I used the serrated screws on all the frame backed areas, and used hollow back folding pop rivets made from Aluminum for all areas that are sheet metal to sheet metal attachment. If I have to remove a panel I will just drill them out.

[Shields]

I rescrewed mine down last year, after one trip half of them were missing. And I went up one size in screws. However, all that did was make a larger hole and many are missing again. I am going to the pop rivet route also, but I sure wonder how many flat tires were behind me.

[markj]

A couple months ago I noticed the same thing under mine--several screws loose or gone. I got some silicone especially for aluminum and pumped a good amount of it in each hole and rescrewed the screws back in. I bought several of the same size--they worked ok, one size up probably would have been better, but either way the silicone has held them fine!

[Wadcutter]

I had the same problem after I hit a racoon that ran out in front of us. You could see where he bounced up against the sheet just behind the axle. I did a sure fix. Took a 1"X3" and cut it to fit between the frame rails inside the belly. Then calked it good using silicone caulk where the sheets overlap. Used 1-1/2" X 1/4" galvanized lag bolts every 8" so they went thru both sheets of metal and into the 1"X3".
Don't forget to replace your insulation before screwing the sheets back together.

[tug911]

I found several of mine loose and I just used some over sized rivets to hold them in place. If you need to access that spot then just drill out the rivet.

[Bob and Renate]

I almost lost a panel on my 2004 29WBLE. I drilled new holes and refastened the panels with a # 10 sheet metal Phillips screw. The way it should be done is drill the outer hole larger, (clearance for the screw body) and size the hole you fasten the screw to the same size as the screw core. Almost all sheet metal fabrication is done the way our panels are installed. Either by using a “drill screw” or using the same size bit for both holes. It is cheep and economic, but the mechanical strength is compromised. By tightening the screw this way the thin sheet metal is easily stripped, without noticing it.
It really works better the old fashion way.

Cheers

Bob