To caulk or not caulk, that is the question.

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1998chinook
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Joined: August 1st, 2014, 2:32 pm

To caulk or not caulk, that is the question.

Post by 1998chinook »

Do you caulk around your windows?

I've read different opinions on the subject. Some say if you have a leaky window to pull it and reapply beutel tape. I was at a Camping World last week and spoke to the service department. He said to simply caulk, that's what he does on his camper.
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Blue~Go
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Location: 1999 Concourse

Re: To caulk or not caulk, that is the question.

Post by Blue~Go »

Not to be too emphatic, but I would say 100% absolutely NOT. Did I mention "not" "ever"? :D

I'll explain how I got there. My background is in boating. There are dozens of pieces of hardware on boats that are sealed with bedding (which is a way to say caulked, although sometimes other compounds are used). Ports (windows) are one of them. Boats pound through seas, often taking "green water" (i.e. solid water) over the deck - not just spray. They also flex while doing so. There is not much harder on a seal than that.

Hardware (including ports/windows) that is bedded always has some sort of flange or "faying surface." Basically a flat area that mates to the surface of the boat (these days, commonly gelcoat, just like our Chinooks). The bedding (caulk) goes UNDER this flange. Anything that oozes out is trimmed or wiped neatly away, as it serves no purpose in sealing, and can actually start to trap dirt/water, plus looks horrible.

Anything that is bedded, eventually needs to be re-bedded. It may be five, ten, twenty, or fifty years later (boats last a looooong time), but it will happen. If it's not done prophylactically, then it's usually at the first sign of a leak. The part is pulled, the surfaces are cleaned and prepped, the sealant (bedding compound or caulk) is put between the two surfaces (underneath the window or hardware flange), the items are put together, any squeeze out is cleaned up, the joint is tested, and then you go on your merry way for another decade or whatever, ploughing your way through the sea, pounding, flexing, etc. The ports/hardware don't leak until it's time to bed again (way in future).

However, there are always people who, through lack of knowledge, bad advice, or laziness, decide not to pull the hardware, but instead to run a bead of caulk AROUND the outside of the joint. This can indeed fix the leak....sometimes even for a week or two ;) Then they usually show up at the boatyard. Either right away with the continuing leaks; or five years later with rot and damage that make the job ten times more expensive.

Caulk around the outside is like if you have a bandaid on a wound and it starts to fall off, so you put another band-aid around the edge instead of taking the first one off and replacing it. A real "band-aid" fix.

I have noticed that this "rim around the outside" is quite common in the RV world. To me it's totally nonsensical. Either the bedding under the flange/fasteners is working or it isn't. If it is, there is no need for anything on the outside of the joint or on top of the fasteners. That just collects dirt and looks bad. If it isn't, then it's time to pull the item, clean and prep, re-bed, and go on your way for another decade. With a clean, tidy rig that doesn't have blobs of dirty caulk on the outside of everything.

Can you tell this is a pet peeve of mine? :lol:

I guess I could have just said "No, I don't." :mrgreen:

PS: I have put something like a bead of butyl tape, or even "masking" tape (but an outdoor type) over a leak if it was discovered on a trip. But that's just to get me home to where I can fix it for real.

PPS: So if your windows are leaking, I would pull them, clean/prep, then re-seal them. I'd use a good quality butyl tape, such as "Bed-It" --- but you could also use some other high-quality sealant.
1999 Concourse
rmasontaylor
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Joined: January 7th, 2015, 8:59 am

Re: To caulk or not caulk, that is the question.

Post by rmasontaylor »

BG thanks for the informative response. Have you ever pulled the window on one of these units and if so how difficult is it to put back?
While I certainly believe in your philosophy some of us might be apprehensive about tearing into something for the first time especially since replacements part for our rigs will be very difficult to find.
The thought of resealing the windows for good measure had occurred to me before when we were headed up the pacific northwest but never materialized.

Thanks,
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Blue~Go
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Re: To caulk or not caulk, that is the question.

Post by Blue~Go »

I haven't taken on of our windows out, but I have dealt with similar/other windows. What I did before I proceeded was to look them up on the web and read the instructions for how to install them - so that I would have an idea how they worked.

The windows on my '99 are single-pane SEGI windows - different vintage Chinooks will have different ones. These are what is called clamp ring style. I'd encourage you to look up instructions (SEGI is out of business, but other companies make similar ones - Motion Windows, Diamond Sea-Glaze, CL Laurence, etc.).

Basically the main window is on the outside. Integral to it is the window frame that you see on the outside of the rig. As you notice, there are no fasteners there. The way the window is held in is by the "clamp ring" that is on the inside. You can usually see it, and it will have many fasteners. So when you first put in the window, you caulk the flange on the outside, push it into place, and then draw it up with the clamp ring.

Of course by now, one could most likely take the clamp rings off and the window wouldn't go anywhere, because the compressed sealant (which looks like it may be black butyl) will be holding it in (although, I'm not saying to drive like that!). It may be a challenge to get them out. Or maybe not. It'd be the kind of thing where you would protect the gelcoat around the window and then ease putty knives or etc. in and slowly work your way around (or, heck, maybe the sealant is dried out and it would fall out, but my guess is not).

The apprehensiveness about tearing into it is probably the reason why most people run the ring of caulk around the outside. And it may work for a bit. What really bothered me was what sounded like a suggestion that this is the right way to do it (i.e. this person did it that way all the time) vs. recognizing it as a band-aid that may work for a time (or may not). When RV shopping I looked at so many rigs that had the rings of slicone, and then a water damage where it had (still) leaked, so admittedly I'm on the negative side with that method.

BUT, I'm also not saying to tear your windows out if you are not comfortable doing it. There is always the potential for something to not go right, and/or for a surprise.

Side note: If anyone does change out their single-pane SEGI windows for another style (some folks have gone with dual-pane Motion Windows, although they do add weight), then I will beseech you to save the little black plastic screen clips and sell me some. I have one screen without them and it's basically useless (stupid design!). I had one saved and took it to about, oh, one thousand RV shops, but no-one had any, and SEGI is out of business.
1999 Concourse
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