Sunrader cabover front window leak...or not

[snail powered]

My Sunraders cabover area has been getting damp. I very carefully caulked those windows last fall but still had some damp coming in over the winter. Not a major leak so I left it on my to do list for this summer to try resealing them again.

Today I cut the plywood on the overcab sidewall further back so it was completely clear of the wrap around windows. Surprise it was not the windows that were leaking. Very pleasant surprise actually because it won't be difficult to fix the source of the leak.

What happened is the original installers when they put on the exterior aluminum trim that wraps around hiding the body join had run the several of the screws all the through the fiberglass. It only happened on the side of the coach just under where those windows wrap around. That error happened on both sides of my rig. That trim channel does fill up with water to a height where it can run in along the mounting screw threads. Or water could have been running behind the channel, maybe even both things were going on. Not a major leak but enough to cause some mold and decaying materials over the years.

If I had not removed the interior wood paneling under that area I would have been convinced that I would absolutely need to replace those windows and their gaskets. Or I would have opted to fill in the window area with fiberglass. But I will water test those windows with a hose before I start putting new interior finishes in. If the windows do leak then that should easily show up with nothing covering up the walls around the windows.

But this particular issue can be solved with a little bit of epoxy putty to fill in the holes. As I am going to be doing some fiberglass work this month I will go ahead and build up that area below the windows (in the interior) with several extra layers of fiberglass tape and resin. It won't affect any of the interior finishes to make it thicker in that area. I don't want any more screws breaking through that skin. I am going to pull the sliding window in the overcab area out on the passeger side and remove that wall paneling for a visual inspection. I suspect there is a another screw coming through in that area as well.

[linda s]

Very good find Karin. I don't believe I have ever thought of that or heard it mentioned by anyone else. In most cases I usually just blame the clearence lights but you don't have any and yes taking the window out and resealing it is a big job. Wouldn't have done the trick anyway. Good call

Linda S

[WME]

Sounds like they sweep up the screws that fell on the floor each day and didn't bother sorting them out for the next day. There reports of Radiers having having long screws through the 110v AC wiring

[snail powered]

I thought the top edge of the cab-over window was leaking because the plywood ceiling panel was delaminated with peeling vinyl paper at the front edge where it touch the rubber gasket on. I have a 1980 Sunrader, the front windows in it do not have clearance lights over them. The windows go all the way up to where the ceiling paneling is.

With a utility knife I cut the 3/16" thick plywood ceiling panel back about 5 1/2" to remove the water damaged section. When I took that damaged plywood section down I discovered that the insulation in the roof stopped at right about that point, it did not extend all the way forward. My window gasket was just fine, nice and tight, not leaking. The moisture damage was instead created by condensation running down onto the plywood ceiling panel from that uninsulated section of the roof. I have now insulated that area with closed cell foam installed with contact cement directly to the fiberglass of the shell.

In a way I have been very lucky with my Sunrader in that I have discovered no leaking windows. The original black butyl rubber window tape installation has held up for 35 years with no leaks. All the leaks that I originally thought were from the windows turned out to be from other sources.

In the rear dinette area what I thought might be leaks from windows were caused by leaks from the fasteners for the original roof rack. Those fasteners are towards the edge of the roof so the water entering them can run down the walls, hit the top of the window frame and run down to the lower edge of the window frame. You would think your windows were leaking. But the first place to check for leaks is from the roof rack. I got rid of my useless roof rack and filled the fastener holes with epoxy putty. Easy job to do and it did not take very long.

I also had numerous leaks from screw holes penetrating all the way through the fiberglass shell in the trim that covered the edge between the top and bottom halves of the fiberglass shell. See discussion and photos of that in the first posting on this thread. The holes were not only in the overcab area, I found another 10 or so in the main area of the coach as well when I removed the wall paneling in the back section. I plugged all those holes and put a layer of fiberglass tape with epoxy resin all along the upper and lower joint line on the inside of the walls. It was obvious that some other fasteners were close to breaking through the skin so I make it thicker to prevent that from happening.