Large rear window leak

[Williston324]

Heavy showers went through this morning and noticed water drips off two inside screws, up high under the shade valance.





It's still raining so haven't had a close up look to the top seal from the outside. Hoping it's not too bad of a fix! Looking at some videos, it looks like the worse case is remove window and complete reseal vs loosing some screws and a small repair. Any tips would be appreciated!

[JRTJH]

Keystone uses (or at least in 2011 through 2014 used) a clay based caulking/putty tape to install windows and doors. Today, you can find a much more durable "butyl tape". The butyl will not dry out and crack as rapidly as the clay based tape. It doesn't "ooze" and "thin" as easily in hot, humid weather.

When Keystone installed your windows, they "supposedly" ran a 1/8" thick "tape" of clay putty around the perimeter of the window flange (starting at the bottom center), put the window in place and "evenly" tightened the inside window trim ring, pulling the outer flange "evenly" against the trailer FILON side wall..... The key is "supposedly"..... Over the years, any small "over tightened" or "thin spot in the putty" will develop a leak.

The first thing I'd do is "EVENLY" tighten the screws in the inner trim ring, starting at the top center and "tighten them" in a sequence similar to the way you alternately torque the lug nuts on a wheel. Top, bottom, left, right, back to top (move over one screw) bottom, etc. Follow that sequence until you've pulled the entire window flange "evenly" against the FILON wall. Then run a "very thin bead of Sika-flex sealant along the outer edge of the outside window flange. That "may" fix your leak, at least for a season or two. Eventually, you'll need to remove the window, clean all the old putty off the trailer and the window flange, apply new butyl putty tape and reinstall the window. Whether you can "stop the leak" for a few more seasons, or for a few more months will depend on how deteriorated the current clay putty tape is, how loose the trim ring is and how much of the existing Sika-flex sealant bead is damaged.

If you do remove your window to reseal it, be sure to inspect the luan inside wall, the FILON backing and the insulation in the area to be sure it's dry and not damaged before you reinstall the window.

Your thoughts about "loosening a few screws and a small repair" is not recommended. Any "small repair" especially along the top of the window, will induce "joints or voids" in the putty if you replace just a portion. That would set up the putty for future leaks. I wouldn't recommend doing that. Either do it all or don't do any....

ADDED: If you do remove your window to replace the putty tape, use butyl tape, start at the center bottom of the flange and overlap it about 1" once you get the putty run back to the starting point.

Good luck.

[Williston324]

Thanks John! Great advice! Now a project for tomorrow. I'll go with Plan A first and hope that works for now. I have a large roll of butyl and will keep it handy if B is required.

[sourdough]

I don't know if you've used the butyl tape but remember that it is VERY sticky and not very forgiving. It is also very hard to remove/mold/cut. If you do pull the window and use it also take into account that it will expand as you compress the frame so leave it a little shy of the outside of the window frame when placing it or you will have a nice, squashed out trim ring of butyl around the window. Good luck on your repair.

[Williston324]

Follow up

Trimmed off the dried putty that had bulged out of the trim and then thoroughly cleaned the area. Did a sikaflex caulk around the window and let it setup for a few days. Did a long water test yesterday and no leaks!! Next season will pull it and replace the putty with butyl. Thanks again for the help!!

[chuckster57]

Sikaflex is VERY difficult to remove once it's cured.

[Williston324]

Just checked --
Used Proflex

[vampress_me]

Question - is this Sika-flex the silicone sealant that would be on all of our windows? Or is it more likely just regular silicone like I assumed? It came from the factory like this, and is harder than anything to remove. It's around the trim on all of our doors and windows, and taillights, etc. Any place they could put it.

[chuckster57]

Proflex is a LITTLE easier to remove than Sikaflex.

Proflex that I see is white and like hot glue but a real PITA to remove. Acrysol works good to remove the residue, but it takes some elbow grease.

[JRTJH]

Our dealer recommended SIKAFLEX and said that is what the factory uses. Whether he's right or not ??? But, all of the SIKAFLEX that I've applied to our trailer has matched what was already there. When installing the LED tail lights, new range hood exhaust and all of the LED lights under the awning, all the "touchup" to door moldings, etc, it's hard to tell the difference between the SIKAFLEX and what the factory used. My guess is that the dealer got that one right....

ADDED: Like chuckster said, it's H*LL to remove. I use a razor blade, cut away the loose/damaged part, clean it well with alcohol and apply a new bead over the remaining sealant. SIKAFLEX will adhere to itself, silicone won't. They do appear very much similar once dried, but if you've ever applied silicone over old silicone, 2 weeks later you can use your finger and peel the new bead away from the old. SIKAFLEX won't peel that way.

[chuckster57]

If Sikaflex comes in different "hardness" then maybe the Keystone factories are using it. Having applied Sikaflex after peeling Proflex off, it sure looks like two very different materials.

Not trying to start any kind of debate, just going by what I have worked with over the years.

[JRTJH]

SIKAFLEX like DICOR makes a variety of different sealants for various jobs. Their self leveling sealant will probably remain "gooey" and run (self level) if used on a vertical surface. I use SIKAFLEX 221 which comes in black or white. It may come in other colors but I don't know. It will not run, is not self leveling and essentially stays exactly where you put it. It's a polyurethane sealant (so it sticks to itself unlike silicone) and will clean up with mineral spirits or kerosene until it "skins over" after that, it's "chisel time" if you want to remove it. I've found it sets up hard (but you can cut it or push a pin into it), won't stain or hold dirt like silicone and to repair/replace it, just cut away the old stuff and apply the new right over it.

I've never used Proflex, so I can't compare the two.

[chuckster57]

221, that's what we use. IIRC the label lists it as an adhesive too. It will hold a slide topper bracket on without any screws!!

[JRTJH]

Yup, it'll also hold the wing panels on an F106 at mach2 in a 6 G turn LOL Of course we won't talk about the popped rivets under the sealant.....It will hole the "metal to metal" even without intact rivets under the skin. "Amazing stuff"

We could always tell when we had an "over G" sortie. When the pilot would start his shutdown checklist, increase the fuel pressure to blow out the pumps and the wings would start to look like sprinklers, it was a sure sign that we were working overtime the next few days...... Lots of SIKAFLEX to redo what they could undo in one "high G" turn...... Ours was an "off red" and never even wore off any clothing it got on.

[vampress_me]

Thanks guys for letting me know what Sika Flex is. This spring when the camper comes out of storage, I have a job to do. Not looking forward to it. On the basement door under the hitch, they used "something" to seal around that frame (like the rest) but this one is loose on the driver's side and needs to be peeled off and redone. It looks like clear silicone, so assumed that is what it is. From pulling the taillight off to put a new license plate holder on, the clear ?silicone? was a bear to remove from the fiberglass. I got off as much as possible with a putty knife, razor, (all gently so not to mark the fiberglass), alcohol (not the drinking kind, although I was almost to that point), soap and water, an eraser...but I couldn't get it all off. I've never had to work this hard to get clear silicone off of anything. So far, used the butyl tape when put taillight back on and it works beautifully. But, now on to the doors in a couple months...ugh.

Do you know what may happen if I put Sika flex on after I'm done pulling off what's on there? Can it go over the remnants of what may be silicone?

[chuckster57]

Is the stuff your peeling off stiff and sticky or rubbery?

Stiff and sticky is most likely ProFlex. Silicone will be rubbery.

[JRTJH]

I use SIKAFLEX 221 on everything I want "permanently installed" and "sealed"... That said, if it's something that will need to be removed later, I wouldn't suggest using 221. I installed my LED tail lights with butyl under the plastic, then once installed and all the butyl trimmed so it was even, after a week of sitting in the sun, I cleaned the butyl again, wiped it down with alcohol and then applied 221 around the perimeter. That was 4 years ago and the lights are still sealed, the bead is white (after washing it) and there's no sign of any voids in the sealant. It's much harder than silicone and doesn't separate from the surfaces as it ages (unlike silicone).

As for applying 221 over silicone, I don't know that it would stick, but I can't tell you it won't stick either. My experience has been that NOTHING sticks to silicone, not even more silicone. So, clean, apply butyl under the surfaces, secure, let it sit and ooze, then clean and trim the butyl again, then apply a liberal bead of 221 around the perimeter. It'll seal the surface, bridge the butyl to join both surfaces and once cured, it's permanent.

Here's the link to the SIKA guide for 221. http://www.google.com/url?sa=t&rct=j...,d.cGc&cad=rjt

[vampress_me]

Thanks Chuckster. It's rubbery. Just like all silicone I've ever used or played with. Just harder to get off the camper than any silicone I've had to remove before.

John, thanks for the link to the data sheet on the 221. Right in there under Limitations it says not to use it over silicones. On other page it says it can be used over silicones that have been removed by grinding it off. Don't think I'm ready to try that one on the camper...

But, since it's 24 degrees out, I think I have time yet to decide how to approach it. Especially with the more information you two have provided me. So thank you!

[tdawg]

Sikaflex is tool able with water and your finger non leveling dicor is not tool able so I would not use that.