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ViribusUnitis · 11-05-2016, 08:15

Let me start this post with the standard refrain.

Hello, I'm buying a boat. My offer was accepted, so I'm going through survey, and with any luck with be the proud owner of a new to me, used vessel. In my case, a steel 'trawler' with "passage making" potential. It's heavy, it's big, it's slow, and it has room for literally tons of fuel.

But like every boat, even new ones, there is always something that's "not quite right". In this case, it's a steel boat, and the windows seals have problems.

The window seals simply aren't sealing, so they must be replaced/repaired. The vessel uses the more or less standard black rubber seals that go between the steel deck house and the glass windows. I'm working on the assumption that I'll need to remove the existing windows, seals, and clean up the underlying metal, before coating it with epoxy and then paint.

After that, what next is the question?

Replace the existing glass windows with new rubber seals? How secure are the rubber seals at holding the windows in place? What if I'd prefer a window that can be opened? Also the boat doesn't appear to have any way to secure a deadlight, so I might what something like that. Studs and acrylic? Or plywood? Or another idea that I haven't considered.

Thoughts?

Cheechako · 11-05-2016, 08:42

Well, they are pretty secure. While testing a new boat design that had glass window/shield, we took on a big wave. The glass broke out , but the seal didn't fail... the glass did. Having said that, I wouldn't be too fond of that type of seal for long term offshore use. I would consider thick plastic windows thru bolted around the opening in the steel.

unclemack · 11-05-2016, 09:01

From your description I'm guessing the sealing strip looks like this.

If so I wouldn't buy the boat.

Those rubber seals are just not seaworthy - they may not hold the window in place if a wave hits it.
Of course they could be replaced but it would be expensive.

I'd always be worried about what other bad choices an amateur builder may have made - that I might not find until the storm hits.

ViribusUnitis · 11-05-2016, 18:42

I think that's exactly the style of the sealing rubber.

It's interesting how different Cheechko and unclemack have with their experience with that style of seal. I know in my personal experience, I typically break the windows long before I get that style of seal to give up. Dropped hammers, and other such stuff that hits windows. That said, I'm not a big fan of the seal, because they always seem to leak after any time at all.

I'm also not a big fan of a "thru bolt" style of window on a steel boat. Every bolt that penetrates the steel deck house is a potential leak point that must be sealed. I don't see the desirability for that when steel has the great advantage that it's easy to weld on studs, or for that matter collars, that don't require penetrating the steel.

As I see my options.

1. Clean up the steel, and replace the windows with new rubbers. Add steel studs, and then plastic storm windows, or plywood deadlights.

2. Clean up the steel, add steel studs, and then use a flexible sealant like butyl rubber to seal plastic or thick tempered glass, storm grade windows under a metal frame. I see this as about the same price as option 1, more secure secure, and probably more leak proof.

3. Find a shop that makes custom frames, and then install custom framed windows that open. Likely I'll have to have studs and storm windows made as well. This would be by far the most expensive option, and I'm not sure I have the budget for it. I would have to install storm windows to be secure. I also question how leak proof such windows tend to be. But I would be able to open the windows, which would be awesome, as you can never get too much ventilation in the summer.

Cheechako · 12-05-2016, 08:56

I'm not a big fan of that seal either, at least for offshore. although as you indicate.... they are much stronger than you might think. We built 50 identical aluminum boats with that seal for the govt/military. For most cruising they should be fine. It's a good way to isolate the shock forces from the steel. And far quicker to replace than a framed window.
There's a name for that seal which evades me.....

**a64pilot** · 12-05-2016, 09:16

Sure likes like the seal that used to be used to hold automobile windows in like on a Volkswagen Beetle, newer cars are glued in place of course

**a64pilot** · 12-05-2016, 09:44

Like this?

http://www.amazon.com/dp/B00BM4N802/...br /> H4YQK873

Open the link and look at the pictures, one is a boat and it has "clips" on the inside of the window, I assume to keep the window from being blown in by water impact?

hellosailor · 12-05-2016, 10:47

It might help to know if this is a professionally built of DIY boat.

Getting windows out without breaking them is often much more likely if you have the right tools, which can be special "cutters" for the seal, or what is basically a garrote made of piano wire, which is poked through the seal and then used as a saw (two people, one inside one outside) to cut the seal.

With modern adhesives, or 3M "VHB" tape (which holds the windows in skyscraper walls) you really can get a bond that is stronger than the glass is. But as in so many boat things, the devil is in the details.

You might also ask your surveyor to comment on the windows, and hopefully he's familiar with steel boats and window options in them.

**a64pilot** · 12-05-2016, 12:03

Never had a steel boat, but I bet if they are leaking, there is rust behind them, and that may be the cause of the leak?

If those are the seals I think they are, they are easily removed, with a long piece of leader wire, the wire will "unzip" the seal if someone is pushing real hard on the window from the inside. Once you see it done, it's amazingly easy

ViribusUnitis · 12-05-2016, 20:43

Yep, that looks pretty much like the style of seal. There are no clips on the vessel's windows however, and I'm not use to seeing them in other applications.

Not all of the windows are sealed that way. The ones facing toward the bow are a different system with a frame. The windows facing the bow don't appear to be leaking, BUT they are set at an incline, so rain almost never falls on them. I ended up looking up a bit about vessel glazing codes, and it appears that windows facing forward are required to be thicker?

It's the windows that are in the other directions that are leaking. There is no question that there is rust under the seals. Many have rust "growing" out from under the seals. In my experience with similar seals on power equipment on land, that's a typical situation for that style of seal. Granted it's on shore power equipment, not a boat. It just seems to me that something about those seals traps water between the steel and the rubber, and then seems to damage the epoxy coating until the rust starts. I think that style of seal works on the rubber and compression, and not the strength of any adhesives. (Not an expert on those seal at all!)

The vessel was professionally built and designed by a naval architect if that helps. The windows are there from the construction of the vessel, and installed that way by the yard. The rest of the vessel is rather thick steel, with heavy gauge steel on the deck house, and .25" steel for most of the hull, all covered in a nice thick coating of epoxy and paint. With the exceptions of the seals on the windows, the interior of the vessel seems to be rust free. At no location could I find rust on the stringers, or ribs anywhere that I looked in the bilge. Most of the exterior is in very good shape, with the exception of some of the hand rails and where they are attached to the decking, which is something that I'd expect to have problems with after a period of disuse.

The vessel has been in fresh water for the last ~10 years of it's 16 year life.

I have a surveyor set up to look the vessel over on the 18th. Haul out, audio gauge, etc. He is familiar with steel boats, and was recommended to me by other surveyors as "the steel boat guy".

Sandibar · 12-05-2016, 22:20

I have rubber seals on all windows. I've broken two windows, but would not worry about the seals holding either. The seals I have allow for a larger glass than the opening in the hull (not like in the above pic by Unclemack - which I would not recommend either, looks like enough pressure could push the window in) and I can't see how they would fail before the window. Installing is a pain without the proper tool to put in the filler strip, but real easy if you have or can borrow one.

unclemack · 13-05-2016, 02:57

Surprised to find one of these still for sale - this is exactly what I used for screen seal removal/refitting back in the 70's & 80's when car makers still used them.
Modern screens are bonded and contribute to the strength of the monocoque.
Easier to fit too I'm told.

Got to be careful refitting the screen/window - all too easy to damage the fresh paint and cause a brand new rust spot.

Other tools I saw today on ebay meant for this same job have long screwdriver-type shanks that would make it difficult to exert enough force one-handed while still under control.
That's the reason this one is so much shorter. Took ages to find it

WINDSCREEN FITTING REMOVAL RUBBER HANDLE INSERT FILLER TOOL KIT 5 ASSORTED TIPS | eBay

**Hudson Force** · 13-05-2016, 03:56

I removed my rubber seals that held my old portlights and replaced them with 3/8" Acrylic plates that are larger than the opening and pressed to my hull with VHB tape by 3M and then sealed with Dow 791.

No fasteners, no leaks and I'm very pleased. Forces acting upon these portlights from outside my vessel press the acrylic against my hull and not stressing against the seal.

Steadman Uhlich · 13-05-2016, 04:55

Quote:

Originally Posted by Hudson Force

I removed my rubber seals that held my old portlights and replaced them with 3/8" Acrylic plates that are larger than the opening and pressed to my hull with VHB tape by 3M and then sealed with Dow 791.

No fasteners, no leaks and I'm very pleased. Forces acting upon these portlights from outside my vessel press the acrylic against my hull and not stressing against the seal.

Hudson always has a wise way of doing things.

This method of using modern adhesives seems best to me for smaller portlights and perhaps for larger glass surfaces too.

I have been looking at older boats, and I like pilothouse boats. The larger portlights would be a possible risk for passage making offshore sailing, but many boats do it successfully and sail for years with big deadlights too. I think securing them with clear covers that extend out beyond the frame is a good idea (storm windows or covers).

Looking at that rubber seal, I would not feel comfortable relying on that on offshore work. But for inshore and typical bay cruising or ICW or near shore typical cruising, windows made of even thin glass can last, and often do.

Since we are talking about "windows" on a boat, show us the boat.

Post some photos. It always helps to see the topic discussed and may lead viewers to new issues or helpful suggestions.