Leaking windows

[what_barnacles]

Is it really this hard to understand?

the blather about polyester absorbing water is a ridiculous argument. The bondo bedding will be completely encased by the window frame. It has zero chance of getting wet.

This from 3M's bondo.com site.

Is body filler water resistant?
Yes. Water absorption tests show that filler only absorbs 0.3% of water,which is considered minimal. Therefore, body filler is not waterproof by itself but is water resistant. Note: If the application is primed and painted, the paint will render the application waterproof.

 

[sdowney717]

Big Bad Bondo

Pictures and info about what can happen with using Bondo on wood boats. My experiences using bondo mirrored those described, wet and rotting wood under the bondo, cracks appearing between bondo and wood. Window gutter frames and bondo likely worse because they naturally get wetter collecting rain.

Might be better if you coat on epoxy over top the bare wood to help seal it, then used the bondo filler. Some folk said Bondo tends to shrink, which would open up some cracking to the wood. I know I developed cracks, then of course water gets in.

Using the Loctite PL mixed with sawdust produces a tight fitting repair, rather than shrink the stuff swells and when cured is similar to wood in that it has some small amount of give to it versus being like a rock.

Epoxy saturation, keeps the water out of the wood, so mostly the wood is immobilized. So a hard epoxy seems to work fine in wood repairs. And I don't think epoxy shrinks.

Epoxy sticks well to wood. Polyester resins do not adhere well to wood. I experienced that using some polyester resin and fiberglass cloth on my boat, after a while the edges wanted to peel up from the wood. Not right away, and not everywhere but took a few years. I ended up prying up the loose glass layer and used a putty knife to force Loctite PL adhesive in, then clamped it down. That has held for many years so far.

I have also used Loctite PL smeared on with a putty knife in thin layers to wood. It creates a slick smooth surface that water can not penetrate. And you have to paint because UV sunlight will eventually destroy it just like epoxy.

It will form some bubbles as it begins to cure, you can drag the knife over back and forth or just let them be. After a full cure, the protective layer is durable, waterproof and tough.

 

[DHeckrotte]

Gentlemen, read Gougeon's (West System's developer/owners) book about using epoxy with wood. That suggested, their premise is that the epoxy saturates the wood (WEST: Wood Epoxy Saturation Technique). It doesn't, at least not very far, and not at all like the old Remington nylon-impregnated wood gunstocks. However, epoxy does stick to wood far better than polyester. As soon as the wood gets wet it swells and breaks the joint between it and polyester. Epoxy is far more resistant to that stress. There's a reason that we don't use polyester resin for bonding wood structures!

All coatings, and many resin-impregnated structures, absorb water. Some are far less resistant than others, that is they have far higher permeability. That's why serious racing sailors pull their boats out when it's not needed in the water, keeps 'em light.

Polyester and epoxy fillers have as little resin and as much filler 'stuff' as possible to keep weight and cost down, and workability up. One of West's fillers is cellulose fiber (ground up tee shirts, I think) so it's reasonable to understand that the cellulose will conduct water while the epoxy surrounding it won't. I don't know what the filler 'stuff' in Bondo and other polyester products is, but it's reasonable to understand that it's also susceptible to water intrusion/absorption. And that's on top of the relatively high permeability of the polyester.

There are other issues, too. Polyester does not form good chemical bonds with itself. It's particularly bad bonding with epoxy. That's why there are special repair gelcoats for use over epoxy. Epoxy, on the other hand, bonds well with wood, well with polyester and pretty well with itself. The 'pretty well' is why a sanded - roughened - cleaned of amine, and any contaminants - surface is required.

Were I repairing the windows shown in the first post, I'd use epoxy coatings and epoxy fillers. I'd work to shape the sill so that water from a failed sealant, or interior condensation, was directed outwards rather than allowed to again get into the wood interior components.

Googling Locktite PL, that's their trade name for 'Professional Line' adhesive and sealant products; there's a wide variety of what that stuff is, chemically; it would be well to choose the suitable ones.

 

[jsc7]

At the risk of quoting David Pascoe again: you can't fix leaking windows with glue.

I see the glue gurus going nuts here with their witches brew of epoxy, putties, polymers, silicones, and who knows what else. IT DOES NOT WORK. Leaking windows are a STRUCTURAL problem. You cannot fix an unsound structure with glue. (direct quote from David Pascoe)

There are untold numbers of sundancers and other boats with much smaller windows than this trawler with glued up windows and they still leak. There are sundancers that there is not even a window any more. It is just one gigantic slab of bondo and epoxy and caulk and whatever else glue. It still leaks.

When a boat has a structural design problem with windows, it has to be fixed in a structural way, not with glue.

 

[FF]

"When a boat has a structural design problem with windows, it has to be fixed in a structural way, not with glue."

Frequently the "structural" problem was simply ignoring PM , the fact that sealants die over time.

Most folks find having aluminum windows too expensive and time consuming to fit.

And boats with solid GRP deck houses too expensive to purchase.

The key is in the Bondo lit , paint it to make it more water resistant , or just use epoxy.

 

[sdowney717]

My two main Loctite PL I use are the PL Premium Polyurethane construction adhesive, comes in 3x and 8x strength formulas. I have not used the 8x quick grab. I have used lots of 3x grab and even works underwater. For filling mix with 30% sawdust.

The other one is the Loctite S30 black polyurethane roof flashing, very similar to 5200 but a little less hard of a rubber and a lot cheaper to buy.
I have mixed with 1/32" milled FG fibers and also used it straight. Makes a real tough durable rubber surface. Used it underwater to cover woodhull, been fine since 2014.
It spreads easily and smoothly with a 6 inch putty knife.

 

[what_barnacles]

The other one is the Loctite S30 black polyurethane roof flashing, very similar to 5200 but a little less hard of a rubber and a lot cheaper to buy.

That looks perfect for sealing the window frames into the window opening. Do you know if it's any good at being an adhesive. I wouldnt mind using for the glass and the window track too.

Now I get to take back the clear 3M Iron Grip. I really didnt want to use it, but I couldnt find a deceny black sealant.. Glad you posted about the S30.

 

[Mkeller]

You need to either be very handy or have a large checkbook if you have leaking windows. I'm in the process of restoring a Marine Trader in which the previous owners had "resealed" the windows using a smear of silicone around the exterior frames after painting them white. No effort appears to have been made to remove and reseal any of the leaking windows. I have found rot around almost every frame as I have pulled windows to reseal. It takes me about 5 hours to pull each frames, clean the window and address any rot around the frame with epoxy putty and new plywood where appropriate and put it all back together. Some windows took a couple of days because of the need to remove and replace the plywood all the ply surrounding the frames. In two instances I found the water problems to have originated at leaky teak brows passing over the windows. The brows instead of channeling water away from the windows actually direct it into the walls and gravity takes its course until the windows debond and become then major source of leaks.

The good news, its been relatively cheap to fix each window using plywood, epoxy, fiberglass and enough sealant to fill every nook and cranny. The bad- it takes more time than I have to give and I don't dare open the checkbook to let a "professional" handle repairs that will be invisible once completed.

 

[psneeld]

On my old Silverton, I might agree about the windows holding up the flying bridge as the only thing that wasnt glass or aluminum frame was the aft bulkhead and that was 1/2 sliding glass doors.

On my tawler, absolutely not.

The windows become part of the structure once in, but I wouldn't call them "structural members".

Why they leak..... is for all kinds of reasons. Sure as an older style boat they do work and eventually they break the caulking around them...price of boating. Done well, they will stay leak free for years.

The only time they become fully part of the structure is when they get 5200ed in. Then they crack because I believe they can't move at all. Saw this on dozens of trawlers through the years. 2 of mine were that way when I bought it....glued in tight.