Weatherproofing 04 Bigfoot

A 3000 series Bigfoot is not a two piece shell like a 2500 or 1500 series. It has a Fibercore wall structure and a seamless rubber roof. I don’t believe Heng’s was used al all on the 3000 series from the factory.

I think the only thing Bigfoot used on the sides is butyl tape under the flanges and silicone on top. So if there is some Hengs or other on side bits it was done aftermarket. I personally wouldn't use that stuff for anything but I'll admit I am way in the minority.

The two halves of the shell have an overlap, the top overlapping the bottom. The trim piece covers the joint and also hides the screws. There is no feasible way to recaulk or improve this seam. However the screws can leak and eventually rot something. I don't know when the crossover was, but originally they used steel screws and then changed to SS screws. I would check yours to see which, if steel I'd go to the trouble of replacing them all with SS, sealing each one with a little PU sealant. The silicone normally spread around that trim does absolutely nothing except collect dirt and mold.

Resealing windows is a lot of work, I'd do what Jim suggests to start with. Also good the clearance lights, they have very little flange sealing them and if the wiring hole was drilled a little bit off, you have leaks. The later models have a very sticky, stretchy sealant that you hate to disturb if it is still good, so it is a dilemma - disturb what may be good or leave it alone until it actually leaks.

Congratulations on that barn find!

Our camper is 20 years old and has traveled almost 200,000 miles on 2 trucks.
It was exposed to sun and weather for it's first 10 years then we built a camper cave for it.

So here is my answers to your questions:

1. I too use the Hengs that is used to seal the vents etc. I do use tape to mask off so the lines remain nice. I clean as much of the dirt off the old surface as I can.. I get up on the roof and inspect each year but I probably do re-seal every other year and only where the cracks are. I have not removed the old sealer. I remove the tape pretty quick after I re-seal. Makes the sealer round off nice.
I have had to replace the fridge vent hood and that was some work..hahahaa. I also have replaced the fridge vent to put a better fan in.

2. After about 5 years I noticed that there was some small gaps in the Butyl tape seal between the window and fiberglass. So during the warm season I tightened the inside screws by just a bit. I found some screws that were totally loose... So after contact was made screwing them down I probably snugged a 1/4 to 1/2 turn on each screw. It took about a month and the tape was really oozing out of the outside surface.. I observed that some of the oozing tape was dirty so that meant that there was no sealing going on. So I watched and finally those spots were oozing clean sealer. After about 6 mos I used a razor blade and removed the excess tape. I did this one more time a few year later.
A bud of mine has a 1987 BF.. All of his windows were leaking because of the tape not sealing. He removed all his windows and re-sealed them. That is a real chore!

3. I have not touched the seams on my camper nor has my bud in all the years. He removed the silicone that was put on the outside of the seam but I did not. The silicone has little mold dots on it but I ignore that.
The way the top over laps the bottom is sealed quite well. I have not heard of anyone having trouble of leaks from those areas.

One thing that is important is the running light seals. Especially the front ones. I had one leaking and the only indication of a leak was the front bed vertical cabinet on the passenger side. It had moisture. WTHeck I said....
I pulled the 1" trim inside that vertical cabinet and then the trim across the bed fwd wall. The water was coming in and running along the foam seams over to the cabinet!
I looked at the way BF had sealed the lights and then I sealed the outside of the lights with a clear house window sealer, not silicone. That was over 10 years ago... No more leaking.

That pretty much covers the sealing and maintenance.
I do wax mine about every year and when I wash it I use a wax as you dry Eagle One.

Congratulations on your find and hope that you will enjoy yours as much as we have ours.

Jim

I wasn’t aware that the recommended maintenance for fiberglass roofs is rubber roof coating. I don’t think it is. But you said there’s existing rubber coating already?

Fiberglass roofs should be essentially maint free except sealing penetrations.
There are FG root coatings which are resin based with fibers. I think that’s what you’re supposed to use if necessary to re coat. ICBW