RV Repair

We experienced some water damage to our rig last January while staying at the Sonoma Coast State Beach (Wright's Beach). Standing outside of the vehicle and looking above the passenger side door I noticed a problem with water intrusion on my Class C Tioga. This water leak created a 1/2 inch separation of the fiberglass floor from the side trim piece. This resulted in the floor being pushed down and away, leaving an unsightly gap. We had rain the night before, but just a small amount. Therefore, I'm thinking this was a problem that had been going on for awhile

The rain became steady, and we decided it was time to head back to Sacramento. This is a 118-mile drive, so I was hoping that we could duck in between showers. As a precaution against further water damage, I used a strip of EternaBond tape to seal it up as best as I could... and made a run for it.


Our luck was not good though; it poured all the way home and rained most of the next month. I was reduced to putting a tarp on the thing and waiting until the weather improved before I could see what extent the water damage was. I was nervous because I didn't know just where the leak that caused the water damage was coming from.

I took my RV to a local RV service center where they performed an overpressure test on the thing. It was pretty much a useless waste of time because the only information I got back was that it was a "leaker". They wanted something like $3,500.00 to "fix it". I asked for a report showing exactly where it was leaking, but I just received what looked like a parts breakdown on the cost of repair. It seemed that their major focus was on selling me a new vehicle. I wasn't impressed.

As far as my leak was concerned, when the rain stopped long enough to begin the repair process, I removed the tarp and looked things over.

The previous owners appeared to have damaged the front right corner of the cab-over by colliding with something. A repair was attempted to prevent water damage, but the external caulking they'd  applied may not have been up to the task of maintaining a water barrier. Upon removing the trim piece, I also discovered more that a few screws had rusted out. It was a mess. The photo shows where the fiberglass was damaged, a result of swelling caused by water penetration. 

In almost every situation, two minds are better than one. I probably wouldn't have enjoyed a successful conclusion to this repair project without the counsel and assistance of my friend, Brian. He has a knack for thinking outside the box, and the tools to back up his ideas.

Because the rain delayed the repair on my water damaged class C, we had a lot of time to think about aftermarket repair products. We mapped out what we thought needed to be done and compiled a list of tools and supplies needed to complete the repair. Brian is a boat owner, therefore, he is always over at West Marine looking at stuff. They carry a selection of WEST SYSTEM epoxies. We concluded that WEST SYSTEM's G-Flex 650 epoxy would be suitable to repair my Class C., even make it structurally better than new. I think this is true in large part due to the waterproofing nature of epoxy when applied to wood.

G-Flex 650 is very new stuff... it was introduced in June, 2007. What makes this epoxy appealing to us was its modulus of elasticity. It has a grip of 150,000 psi (pounds per square inch). WEST SYSTEM's number one selling Epoxy, the 105 series, has a modulus number of 405,000 psi grip. This relates because G-Flex has nearly the same creep (creep shows how long an epoxy will sustain a load without separation) with much enhanced tensile elongation (five to six times the tensile elongation of WEST SYSTEM 105). Tensile elongation is a simple measuring term determining how much movement can be absorbed before shearing, or breaking apart.

So, how do all of these numbers relate to a repair project on a water damaged motorhome? Well, we needed something that would return the underlying sub frame wood back to its original integrity. G-Flex has the ability to:

With the above information, we decided there was a good chance the old motorhome would not shake itself apart as we drove down the road. Ok! We felt good about the epoxy. However, we still needed some type of insulation tape. I didn't want to use plumber's tape because I knew it would become hard and brittle after period of time. So, I looked on-line at 3M. We got lucky, and found another new product recently developed by 3M. They had just brought a new weather ribbon seal. The stuff is pretty cool, it will stay pliable over the long haul. This is a quality that will prove to be very effective for our purpose.

I ended up using a supplier out of Sacramento, CA called R. S. Hughes Company. I bought a roll of 3Ms weather ribbon seal. It was 1" wide and, as you can see below, matched perfectly with the existing trim piece.

The last piece of the puzzle was finding a substitute for silicone. Although silicone has good sealing qualities, it becomes a real bugger when it is time to replace it. This is because silicone does not stick to itself, so it must cleaned completely off whatever surface that must be sealed. Chemical removal helps, but it always boils down to a lot of elbow grease. I used a commercial silicone removal product to get the big pieces off. But, I found a common wet sanding sponge worked best to remove it entirely. I really don't like silicone.

I finished completing the final caulking with a Geocel product call PRO FLEX. Bottom line, it has all the sealing qualities of silicone, but it is capable of being reapplied to itself, or even painted, after it dries. One hundred stainless screws were used to replace the original factory screws and a 4' X 4' X 3/4" plywood board was used to help brace the repair area when applying epoxy.



Reprinted with permission of class-c-motorhome-info-made-simple.com.

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