Another leaky windshield. And the DIY fix.

[Purple tent]

I have 2 guns one cheap one with a short handle and one with a longer handle for your hand. Because the caulk is a lot thicker than normal caulk I could not squeeze it out with the cheap gun. The gun with the longer handle was easier to get the caulk out of the tube.

[CJ7ole]

Originally Posted by resqguy

I have a small leak on my passenger side and bought some 3M Urethane Adhesive to patch. I keep seeing recommendations to use a good caulking gun. What exactly is a good caulking gun? I assume I need to remove the cover on the bottom of a tube. Any other special instructions when handling this stuff?

Yes, you want a gun with a good mechanical advantage as the goop is quite thick and difficult to squeeze out with a lesser gun. Go to a hardware store or HD and most guns will spell out the ratio on the tag. At HD I got the one with the orange cast handle. And wear gloves, that stuff is very difficult to remove from your skin, cheap nitrile ones work fine and are disposable. IIRC there is a seal on the bottom of the tube you don't normally see on a tube of caulk that must be removed. The cap inside the bottom of the tube just gets pushed up into the tube by the gun's rod. And there may be a seal inside the nozzle you pierce multiple times with the stiff wire attached to the gun.

[CJ7ole]

Here is the gun I use, from HD, about $12.

[CJ7ole]

Update: 18 months and all is still well, but it is just a matter of time...

Meantime I ran across this video in a recent windshield leak thread:

https://www.youtube.com/watch?v=zbXoyP9d5lI

Watching the video, he says the primer he used after grinding away as much rust as possible is Essex 5504G. Google and it comes up as CRL or DOW and is called Betaprime. His reference to Essex 5504G is probably because several folks seem to bottle the stuff. The base reason the installer gives for the rust problem stems from Winnebago's use of (cheap) open cell foam double sided tape to hold the trim retention strip in place. Open cell foam will absorb water and allow it to keep the base metal wet much longer than standard automotive closed cell double sticky foam tape. I don't know if this is true, but it makes you wonder why Winnebago would make such a basic mistake in choice of materials.

Has anyone ever heard Winnebago explain why they haven't properly addressed this long running major problem?

[BobC]

I'd previously posted this separately but haven't received any answers, so I'll try here:

I've been reading as many posts as I can find regarding windshield leak repair. Most mention sealing the bottom edge of the roof cap under the reveal molding as well as the roof cap to roof joint.

Is sealing the bottom edge really a good idea? I'm not sure of what's under the roof cap but if water did get under it, say from a leaking roof to cap joint, wouldn't caulking the bottom edge keep the water from draining out?

The sealant callout sheets I've looked at don't show a sealant for this, just for the cap to roof and cap to sidewall. I'm wondering if the bottom joint is left unsealed by the factory on purpose. It seems to me that the secret is 1) Exclude as much moisture as possible and 2) Allow what moisture does penetrate to drain or evaporate.

Comments?

[70ChevelleSS]

Water from above, front cap to roof or clearance lights. Sealing front cap to roof is easy and it's not an area prone to leaks. Clearance lights, replacing the gaskets if available or making new ones like I had to seals them. If water does get in at clearance lights it backs up and falls down on the bottom side of the overhead cabinets, had that problem. The main area that allows water in is the rubber trim piece. It's cosmetic only and won't keep water out. I sealed mine to front cap with 3M trim adhesive tape. Now the only time water can get in is when driving into a heavy rain, water can get pushed up under the bottom of the trim piece. Our motorhome has sat through numerous down pours with no leaks. I did experience a minor drip last month driving to FL. in heavy rain. Guess I could seal the bottom edge same way I sealed the top.

[BobC]

Thanks, 70ChevelleSS, I agree, but my question had more to do with the suggestions that one fill everything behind the rubber trim with caulking. I'm thinking that, if water gets in, I'd rather have it find its way out via the bottom or ends of the trim or evaporate. Whatever caulking is put in the channels behind the trim will be imperfect and create places for water to accumulate, from which it can't drain, promoting rust, etc.

[CJ7ole]

The problem is that water WILL get in based on the original design and you will get rust. The idea is to seal is so well more water can't get in. Just seal it after it has sat in the hot sun long enough to evaporate any water now in place.

[CJ7ole]

Knock on wood, but another year has gone by with no leaks.

[erstanfo]

Just to update everyone, I replaced my windshield in 2015. Took it back this week to the glass place to check the leak I had. It is not the windshield, but the fiberglass cap to metal frame seal has failed. i'm in the process of digging out the old white sealant above the U channel. Need to clean, treat rust with Ospho paint and re-seal the 1/4" gap. I also plan to glue the trim down with sealant and add 2" electrical tape as more insurance.
Ed

[CJ7ole]

A few drops last spring, ok since then. Still keeping my fingers crossed.

The Eternabond white tape at the top of the black rubber trim strip has discolored from the black rubber, but is holding up fine otherwise. This tape is designed to sit in the sun for years. Don't try any other kind of tape except for a very temporary solution.

[BobC]

Update: Shortly following my posts in Feb 2017 (#45 & #47), I sealed my roof cap, top and sides, with 4" Eternabond and ran a strip of 2" Eternabond across the top of my windshield after cleaning out all of the messy silicone the PO had put under the rubber moulding.

I didn't seal anything below the top edge of the windshield so as to not trap any water (see my earlier posts). The Eternabond laps over the top edge of rubber moulding, leaving the bottom unsealed. It's now been 32 months since then and not a drop of water inside despite being stored outside year-round.

By the way, if you buy 4" Eternabond, it's easy to split into 2" strips with a straight edge and utility knife.

[iezzif]

Had a problem with water dripping from the overhead cabinetry and onto the dash and cartpeting. Thought it was the windshields and started taping the gaskets. Still leaked. Found that my front clearance lights were the issue. Removed and sealed them. No leaks

[jabass]

I used rubber tape around the outer frame of windshield and down the sides. Also caulked the tops of my running lights over the windshield. The rubber tape will have to be replaced about every 2 to 3 years, but it is worth it for piece of mind.