Butyl tape for windows?

The "nor'wester" that came through the upper Chesapeake yesterday (wind is worse today, but at least the rain has stopped) revealed leaks on a few of the main salon windows. I've used 4200, 5200, Sikaflex and other caulks for various projects on other boats over the years, but butyl tape has been fantastic for most bedding applications. I plan to rebed all of the deck hardware with butyl tape, but I'm less sure about using it for windows. Most of what I've found on line is from people who have tried it on windows, but no one with long-term experience.

Has anyone used butyl tape for windows for any length of time and how has it worked out?

angus99 said:

The "nor'wester" that came through the upper Chesapeake yesterday (wind is worse today, but at least the rain has stopped) revealed leaks on a few of the main salon windows. I've used 4200, 5200, Sikaflex and other caulks for various projects on other boats over the years, but butyl tape has been fantastic for most bedding applications. I plan to rebed all of the deck hardware with butyl tape, but I'm less sure about using it for windows. Most of what I've found on line is from people who have tried it on windows, but no one with long-term experience.

Has anyone used butyl tape for windows for any length of time and how has it worked out?

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Used it on aluminum framed (RV style windows) that replace all 15 major windows on my boat and it has been good for 2 years. Only leaks were from where the cabin side was just so irregular I didn't have enough in there. Most of the time I folded it in half to get good squeeze out all around.

I have pulled a couple windows since and the cleanup and re-taping was easy.

Thanks, Scott. Not sure how my Defever windows are constructed, but am pretty sure the bedding will be directly on the glass. Glad to hear it's working for you.

Aluminum windows on aluminum walls, also a previous engine change access hatch in the roof. One year.

All of my windows use butyl tape--I wouldn't use anything else. V-berth windows are just now showing leaks after 30+ years (they are being replaced and will sealed with butyl).

Not familiar with this. Anyone got a brand or a pic?

Ski in NC said:

Not familiar with this. Anyone got a brand or a pic?

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You can get Bed-It Butyl tape at Compass Marine.

I've used it on my deck stanchions and hardware with no issues at all…..love the stuff for SEALING. If you've got compression style perimeter mountings on your windows, have at it! I plan to do the same. I've got two year old balls of butyl tape I left on my deck in the sun and weather. The stuff still feels just as flexible and capable.

Anyone that has been around classic cars will be familiar with butyl sealant. The front and rear glass of my '71 AMC Hornet uses butyl and is still water tight after 40+ years (never been replaced). Urethane windshield adhesive has largely replaced butyl because it is much stronger but many classic car owners still use butyl. I have to replace the rear glass because of some rust and will use butyl. Butyl can be messy and sticky but cleans up with mineral spirits.

My windows have had no issues. All sealed with butyl. 1984

Butyl tape is all I use on my boat, RV, and anything else I need a reliable seal on. Great stuff.

Thanks, guys. I got an email back from Rod, at Compass Marine, who also says butyl is excellent for bedding windows--in addition to deck hardware. So, big project coming up!

Butyl works great when you are dealing with though bolted items where you can really compress it evenly. If you are dealing with screwed items make sure you are dealing with a good surface hole for the screws so that you can compress evenly. The only time I had an issue with it was in that case and I needed to redo the hole anyway. Works great for many other uses too.

Any RV dealer , or any box store like Home Cheapo or Lowes will have it at non marine pri$es.

We've resealed windows with butyl and have had great results. We also used to to reseal all the deck fittings on our old sailboat. It is the only above the waterline sealant we use for fittings that have mechanical fasteners. Our windows had internal aluminum frames that screw to the external frame that holds the glass (sandwiching the boat and sealant). We bought from RC at Compass and the stuff he carries is excellent. No comparison to the crap that we got at Home Depot before learning about compass.

Anyone have a link to a tutorial for using butyl ?

Tunajoe said:

Anyone have a link to a tutorial for using butyl ?

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EDIT: wrong link....see next post by angus99

And:

Re-Bedding Deck Hardware With Bed-It Butyl Tape Photo Gallery by Compass Marine How To at pbase.com

Not knowing the configuration of the OP's frames, I'll just chip in that Hatteras used and recommends butylfor bedding the inside of th glass, but a glazing specific caulk for the outside. I figure there is a reason for that, and I believe it is because it is easier to get the caulk into all the nooks and crannies on the outside, which involves various splines and shims and exterior frame. I redid all mine (after 30 years) with a old time ex Hatteras guy and he was pretty insistent as well.

caltexflanc said:

Not knowing the configuration of the OP's frames, I'll just chip in that Hatteras used and recommends butylfor bedding the inside of th glass, but a glazing specific caulk for the outside. I figure there is a reason for that, and I believe it is because it is easier to get the caulk into all the nooks and crannies on the outside, which involves various splines and shims and exterior frame. I redid all mine (after 30 years) with a old time ex Hatteras guy and he was pretty insistent as well.

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I would concur...butyl tape for bedding frames...but I would go with the best glazing compound (something 3M if I recall correctly) for glass

I switched from grabbing 5200 by default to using a good quality Butyl tape. Thickness of the tape matters and I've seen different qualities of the stuff. I think Compass has the best tape going for most normal uses.

It's been over 3 years since I admitted that I was a 5200-aholic. Today, I almost never use 5200 any more.

https://activecaptain.com/newsletters/2012-09-12.php

Karen and I were just talking about seeing if we can get a discount for ActiveCaptain readers for the marine quality tape from Compass. If so, it'll probably be next week. I have an idea I'd like to run by him that would help his sales with a big shot.

>Today, I almost never use 5200 any more. <

It still is great for stuff that will never, ever be taken apart. Never as bedding .

I used 5200 on my sailboat to rebed stanchions, deck hardware and hatches. Tenacious stuff for sure, but not that hard to get off with a heat gun, a razor, some pressure and patience. I only removed a few pieces this way that were being replaced or installed in a different location, but I found 5200 to be excellent for bedding stanchions, genoa tracks and other components that took heavy loads.

That said, I didn't know about butyl tape or I'd have used it in a heartbeat. I've been blown away by the testimonials, demos of elasticity, sealing power and long life of this material. I have 2 rolls of the butyl Compass Marine sells and would love to see a discount (much as I believe CM deserves our support). It's not cheap, but quality often isn't. And, if I tallied up all the half-used 5200 tubes I've thrown away because of its short open shelf life, I could have bought a lot of butyl tape.

Good prices on BUTYL TAPE.Also,different sizes and lengths.

Angus,

I've used 3M 4000 or 4200 to seal deck hardware and such but will only use butyl now except for some special circumstances. Interestingly, butyl was used extensively years ago for sealing deck hardware but now there seems to be a return to it based on what I am reading on the Internet. What is old is new I guess.

Vashon_Trawler said:

Angus,

I've used 3M 4000 or 4200 to seal deck hardware and such but will only use butyl now except for some special circumstances. Interestingly, butyl was used extensively years ago for sealing deck hardware but now there seems to be a return to it based on what I am reading on the Internet. What is old is new I guess.

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It was also used in mobile homes in the 60's through at least the mid 90's to seal windows,doors,and vents through the side walls.

ben2go said:

Good prices on BUTYL TAPE.Also,different sizes and lengths.

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But is it the same stuff?

The guy at Compass worked for Sabre from what I understand. He used Butyl tape there. I read somewhere that he tried others and none compared to the marine supplier that Sabre used. That's the stuff he sells. And first hand, it's fantastic.

Are there different grades, types, models other than by measurement?

Jeffrey S said:

But is it the same stuff?

The guy at Compass worked for Sabre from what I understand. He used Butyl tape there. I read somewhere that he tried others and none compared to the marine supplier that Sabre used. That's the stuff he sells. And first hand, it's fantastic.

Are there different grades, types, models other than by measurement?

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Good question.This I have no answer.I would ass-u-me that different manufactures would have a little different composition.I've only dealt with the stuff from big box stores.

My first rolls were from compass marine...a great guy, an asset to boaters and I respect him a lot.

Subsequent rolls were from Home Depot (OK) and the last one I got in black to match my windows from the local camping supply/trailer place and it seemed identical to the compass marine tape. Both came packaged the same way, had the same texture,were the same size although you can get different sizes....

Yes I would say there's different quality tape...but most you can touch when purchasing and can tell if it feels right....but for ease and quality assurance...compass marine is a good source...

But I a pinch it can be had pretty easily....

>And, if I tallied up all the half-used 5200 tubes I've thrown away because of its short open shelf life,<

Sealing the open end air tight and leaving it in the fridge helps.