Caulking around Wood Windows

I am having a bit of trouble deciding what caulking to use to reinstall my Marine trader wood framed windows. I am leaning towards either SilkaFlex-291 or SikaFlex High Strength Adhesive & Sealant 2921.
I have no experience with either product, so help would be appreciated. Or if there is a better product please let me know.

Thank you

Bill

Use something you can remove in about 10 years time to do over again.

Although our windows are not wood, they're aluminum - the seal is just as important. We re-caulked all of them with DAP 40 year acrylic latex. Local builders use it here on the coast for caulking everything exposed to the same salt, wind environments we are. Easy clean up and paints easy. Been on for 2 years now - zero issues.

Edit: If you are looking for something to bed the frames in, Sika is a better product. This is for caulking, once the frame is set properly.

Sika 291 worked for caulking my teak toe rail. I used their primer on the wood first. Expensive at about $80 per can, but I wanted it to work really well.

ToTheLimit said:

I am having a bit of trouble deciding what caulking to use to reinstall my Marine trader wood framed windows. I am leaning towards either SilkaFlex-291 or SikaFlex High Strength Adhesive & Sealant 2921.
I have no experience with either product, so help would be appreciated. Or if there is a better product please let me know.

Thank you

Bill

Click to expand...

Boatlife

Butyl tape.

You don’t want a real strong adhesive since at some point you will need to take it apart to rebed it. I love buytl tape in through bolt situations, but if you are just screwing the windows in you probably won’t get enough compression to squeeze the butyl properly.

Comodave said:

You don’t want a real strong adhesive since at some point you will need to take it apart to rebed it. I love buytl tape in through bolt situations, but if you are just screwing the windows in you probably won’t get enough compression to squeeze the butyl properly.

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I did a couple of windows this year. I started with butyl tape, but the only tape available now (reformulated to be harder) was not soft enough to be sure of a good bond, so I abandoned that idea and used sika 291 with perfect results.

Yes, I love buytl when you can get enough compression on it to insure a good seal, but when you use screws it doesn't get enough pressure to seal the butyl. I do use it where ever I can through bolt and it is great. I get my butyl from Compass Marine, it is pretty good.

3m4000

NightCrawler said:

Although our windows are not wood, they're aluminum - the seal is just as important. We re-caulked all of them with DAP 40 year acrylic latex. Local builders use it here on the coast for caulking everything exposed to the same salt, wind environments we are. Easy clean up and paints easy. Been on for 2 years now - zero issues.

Edit: If you are looking for something to bed the frames in, Sika is a better product. This is for caulking, once the frame is set properly.

Click to expand...

Nightcrawler, following the conventional wisdom of "no silicone on boat" I would assume that this version of DAP with silicone would make repainting the window frames down the road a problem maybe? I need to repaint and caulk mine but not removing the windows totally. Paint would be first of course with caulk as final step. Just wondering what happens a couple of years down the road when I need to do it again...

I used black Loctite roof and flashing polyurethane in a cartridge for my wood frames, turns into a soft rubber.
First though I smeared on a layer of epoxy onto the wood to seal the wood where the glass sits.

I don't agree with this idea of using some loose stuff so you can reseal it when it leaks.
All I did was caulk around the glass. Spaced the glass in the frame and filled the gap.
My windows are inset a little bit so I smoothed the interface with my finger. The stuff washes off with soap and water so easy cleanup.

If it leaks, just clean away the leaking seal and put on a new layer for that section. I have not had to do that.

Dap Dynaflex 230 acrylic latex caulk is also good stuff, but it will turn into a hard rubber seal. Comes in black and other colors. With wood to glass, it might be too hard of a rubber, wood and glass might move at too different of a rate, the seal may break. But wood to wood it is real good for seaming planks.

I’d use 3M 4200 or whatever if there has been an update.
SikaFlex 291 is my favorite but it is a bedding coumpound and so may not ideal as a caulk. I’ve used SikaFlex for many years on practically everything and have no complaints but as a seam coumpound or to caulk an angled joint (such as windows) again it should’nt be ideal but I just can’t recomend it to others 100% for windows not knowing it’s UV resistance. But for a removable caulk for windows it should be fine.

Are your surfaces teak, FG or other?
Life Caulk would be my vote if it was teak.
Also the adhesion should be fair to good for a slick smooth surface like glass and also good to your wood.

1 vote for butyl tape (if you're using screws to hold them in)
if you're counting on the caulk as an adhesive (that's totally fine), I vote for 3m 4000

Hi Bill,

I'm not familiar with the OEM installation of the wood framed windows on your Marine Trader. I can only offer my experience with living with wood framed windows for many years on my Canoe Cove. The Canoe Cove had a fiberglass cabin, cored with a teak veneered marine plywood on the interior. The frames were let into openings in the cabin sides, and screwed through the fiberglass exterior into the plywood core. Teak trim was screwed back through the core from the interior to trap the glass, and complete the install. I'm guessing your Marine Trader is similar.

The Canoe Cove OEM installation of my teak window frames used Sikaflex 291 as a bedding compound. I continued to use it for many years when performing the difficult and tedious task of maintaining and repairing the windows on my boat. And you WILL have to re-bed and re-caulk at least some of your frames and glass with regularity to maintain a water tight seal. And I further suggest you plan for replacement of window glass, should something untoward occur.

291 is sufficiently viscous to allow the screws to bed the frames properly into the salon window cutouts, is very easy to tool into fillets around the frames and window glass, and is removable in the future without damage. It forms a tenacious bond with window glass, assuming the installation instructions from Sikaflex are rigorously followed. It is also available in other colors (mahogany, for instance) should matching natural or bright-finished teak window frames be of interest.

In my opinion, use of butyl tape for this purpose, in combination with screwed-in-place wood frames, is absolutely not appropriate. The tape is too stiff to allow the screws to bed the frames properly, without either deforming the frames, and/or stripping the screws. Use of household products in the marine environment for window frame bedding and sealing is equally problematic, as the household environment, even immediately on the foreshore, is NOT equivalent to a marine environment. Dunno about your house, but mine doesn't vibrate and flex while underway in a seaway, as does my boat. While 291 is spendy, you gets what you pays for.

3M4200 is also a fine product for this application, both for bedding the frames, and forming filets around the glass. Same viscous nature, same UV resistance, same cost (more or less) than Sikaflex 291. Different installation procedures though-make sure and check with both Sikaflex and 3M should you chose to use their products.

Again in my opinion, NO NO NO silicon-based products. Never on my boat, anyway. Ditto for 3M5200. Great adhesive, lousy caulk.

Regards,

Pete

I agree with Pete on every point.

Thanks Pete, that is great info, I will be ordering some 291 today!!!

Cheers,

Bill

Before you move too far along, study this product. I have used it in several boating window issues, passed the good of it on and others have reported the same success. Application is easy. The product will seek out and find the same leak the weather is providing you currently. Secondary applications will solve the leak as it is found by the flow of the product. Apply it to the top and sloping sides of the window, as it disappears into the seams will indicate the leak location (or potential).
Worth an attempt prior to application of "Stuff".

Al-Ketchikan

https://www.boat-renovation.com/captain-tolleys-creeping-crack-cure-full-review/

ToTheLimit said:

I am having a bit of trouble deciding what caulking to use to reinstall my Marine trader wood framed windows. I am leaning towards either SilkaFlex-291 or SikaFlex High Strength Adhesive & Sealant 2921.
I have no experience with either product, so help would be appreciated. Or if there is a better product please let me know.

Thank you

Bill

Click to expand...

Here's a great Sika Application Chart for their products.

I appreciate the comments about butyl tape. I've got Compass Marine's butyl tape for other projects like sealant on wiper blade motor mount, antenna mount, horn mount and similar installations. Had wondered about its compatibility on my windows if I ever get around to redoing them.

A couple of my panes were sloppily repaired before I bought the boat (....I swear, it wasn't me!!) I've wanted to tackle them but have never done windows before so I keep putting it off. Since I have a covered slip in Northern CA, there's not much opportunity for window leaking here and they're still holding 11 years later. Therefore they remain at the bottom of my list.

Not seeing the link?

Bill

It is hard to know from your question, whether you are redoing fixed windows or sliders.

In my C&L 44 (looks like a Marine Trader, so the method of installation may be similar), each is installed differently. The fixed windows are well designed and shouldn't ever need to come out, unless you need to replace the glass.
Sliders, designed to leak, will need to be removed and fixed, and if not fixed properly, will need to be done again.

Search for my re-do thread on my sliding windows, of which I reported within the last couple of months.

ToTheLimit said:

Not seeing the link?

Click to expand...

Original link is working for me but here is another take on it....

https://www.jamestowndistributors.com/userportal/document.do?docId=1007

Just click the Sika Application Chart

and you get taken to this site.

https://www.jamestowndistributors.com/userportal/document.do?docId=1007

Capt Tolleys is 12.5 pounds on the UK site, and $66.00 on Amazon.ca. Whats up wit dat?

I ordered from the UK at half the price incl shipping.

Captain Tolley's is $8.96 US for 2 oz / 60 ml at Fisheries Supply in Seattle. Around here West Marine will price match that. https://www.fisheriessupply.com/capt-tolley-captain-s-creeping-crack-cure-ctcc

Now the question I have is will it fix some minor window leaks.

Currently scared to test the border with the US for shipping. It can get hinky.

Greetings,
I've used Capt. T's sealer on exposed gauges on the FB of our small boat. The gauges would fog up after a rain. Worked as advertised. Glass bezel with chrome trim.

Mastic for windows

You need something that will flex - not silicon.
Best is mastic - it sets on the outside skin and remains soft and flexible in the frame.

Greetings,
Mr. t1. Welcome aboard. I fully agree NEVER silicone. I would suggest Dolfinite. https://www.jamestowndistributors.com/userportal/show_product.do?pid=4400