Is Butyl Tape Still Recommended??

[Secondshift]

I've used

rope caulk, cheap butyl tape, 5200, 4000 , Boat Life polysulfide and
(whisper ) sometimes silicone.

My preferences have come from books, trial and error and sometimes opinions on the internet.

I feel there is no one product for everything.

I've seen the cheap butyl ooze in the FL summer sun but not leak and stop oozing after some settling.


I've used polysulfide under wooden grab rails and such. It's a pita 2 day process but it creates a form fitted, flexible and easily removeable gasket. It can attack some plastics.

I have caused some damage (and lots of profanity) removing items bedded 4000/5200 BUT I find it's still the best choice for some situations.



Good Luck and Best Regards

[Island Time O25]

It's the "aspirin" of sealants. Of course the manufacturers of "new and improved" stuff want you buying their still patent controlled expensive sealants rather than cheap oldie but goodie butyl tape.

As explained to me by a boatbuilder friend (300+ boats built in his professional career).

[lockie]

I have used butyl tape for nigh on 10 years now and by now every one of my deck fittings has been sealed with it. I have had only one leak in that time, and that was early on and was due to my poor workmanship, involving using far too much of it. It has very different characteristics from the gooey stuff that you extrude out of a tube, and so you have to treat it differently.

When I first started using it, I would use heaps, making it into sort of like a full gasket for the entire surface of the fitting, and it would continue oozing out for a long time. These days, I form it into a thin "O-ring" to encircle each screw, with a diameter large enough so that it doesn't squeeze in and get caught up in the thread. Another little o-ring goes under the screw head. One important factor is that you do need to retighten the fasteners once or twice after a day or so to accommodate the slow “ooze” under pressure. And it is not an adhesive but relies totally on fastener pressure.

As above, my success rate is 100% if I exclude my crappy fail. But of course this is imho and ymmv, caveat emptor, don’t blame me etc etc.

Cheers, Graeme

[Spindrift NH]

I’ve been using bed-it from Mainsail for about 9 years and find it to be a very good product. It does take some time to develop a system for working with it for application, proper prep and on difficult to reach parts I actually practice how I’m gonna handle the parts before adding the butyl. One trick I’ve learned is to cut pieces off the roll with scissors, don’t tear it.
While I like butyl for bedding items, I actually use more of it for temporarily sealing openings on a project that takes multiple weekends or while waiting for parts. The photo is of the deck penetration for my chainplate, not sure how long it’s gonna take to get replacement chainplates so this system will keep water out for as long as it takes and it’s easy to clean and prep for final install when the time comes.

[sinnerman]

I just removed , cleaned and re-bedded the windows in my Catalina 30 (not an easy task). They were previously installed with Butyl (or similar) and it was dried out and hard like old modeling clay. I reinstalled the windows with 3M 4000 UV.

For my new lifeline stanchions, I opted for the Bed-it tape from the Marine Know How site. So far, no leaks but we shall see how it goes. Since the stanchions get a lot of side loads, I felt that the butyl tape was a better choice as with 3M 4000 I felt there was a chance there of the adhesion bond breaking under bending load. One PITA issue with the tape however is that you have to go in and re-torque several times as the butyl "seats" itself.

FYI the stanchions were previously installed with silicone and there were zero leaks. Having previously been installed with silicone was another reason I used butyl (bed-it) tape as the 3M 4000 will not adhere if there is any silicone contamination.

Cheers

[Emouchet]

Butyl tape is excellent the prevent any water ingress when bedding stuff on deck.

But it has very minimum holding power. You need to add some mechanical holding like a bolt of screw or something else.

It cannot be used like 5200 or 4000 or Sikaflex 291 to glue anything and hope this will hold tight.

[Barkingmad]

There is no one magic product, I use what is appropriate for the job. Sometimes butyl sometimes something else. About the only one that has NO place on MY boat or my house is silicone.

[LargeMarge]

2003, we converted a 1997 Ford CF8000 commercial truck to our concept of an ExpeditionVehicle.
.
We sealed our windows with Vulcum 116.
Nearly two decades full-time live-aboard, up rough logger tracks to remote mountain lakes and across deserts to isolated Baja beaches, our Vulcum 116 remains soft and pliable.
.
Would we use it again?
Yes!

[JBsurfin]

Originally Posted by S/V Illusion

Butyl was highly marketed by the folks selling it, not by those using it.

For those who don’t know how to properly use liquid sealants, butyl is idiot-proof.

For those who aren’t, use the proper sealant.

would totally disagree with your assessment. I've used Butyl tape for years on my 83 Ketch. As per other posts noting melting, oozing, etc. I have never had any such issue when properly applied.

I've worked on various boats for over 40 yrs with both sealant and tape. Each have their intended use.

[Knapweed]

Not wanting to derail the flow, however, I have a niche use on my True North 34, for which, I would welcome advice. Four of my shrouds are attached to plates under the deck that are held there by the tension of the shrouds. Imagine a rectangular stainless steel plate 8" x 6" x 3/8" with a tang in the centre that protrudes through the deck and attaches to the lowers.


I wish to re-bed these plates later in the season as they haven't been touched for at least ten years, however, there have been no leaks and this is more along the lines of preventative maintenance, i.e. checking the integrity of the stainless steel plates once removed.


I assume good quality butyl tape would work well for the plates under the deck as the sealant will be under constant compression, however, what would contributors recommend for the seal around the tang that protrudes above deck?

[JBsurfin]

Originally Posted by Knapweed

Not wanting to derail the flow, however, I have a niche use on my True North 34, for which, I would welcome advice. Four of my shrouds are attached to plates under the deck that are held there by the tension of the shrouds. Imagine a rectangular stainless steel plate 8" x 6" x 3/8" with a tang in the centre that protrudes through the deck and attaches to the lowers.


I wish to re-bed these plates later in the season as they haven't been touched for at least ten years, however, there have been no leaks and this is more along the lines of preventative maintenance, i.e. checking the integrity of the stainless steel plates once removed.


I assume good quality butyl tape would work well for the plates under the deck as the sealant will be under constant compression, however, what would contributors recommend for the seal around the tang that protrudes above deck?

My chain plates come through the deck on my 83 Dickerson Ketch. I packed the tape into the hole around the chain plate and then placed it flat to the deck and replaced my cover plate that screws down, adding compression. After a couple of days, retighten the screws a bit, wait another day and used a razor knife to cut back the excess. Been that way for 5 yrs now, no leaks. As noted, get quality tape.

[stvnm]

Yards hate butyl because it is way more time consuming to install properly. The surface must be clean and free of contamination. I find that using mineral oil for cleaning primes the surface and bed-it bonds perfectly. 5200 is not a sealant. Is an adhesive. For bedding places where there maybe contact with diesel polysolfide is oil and gas resistant. 4200 is fine but has a few years life span. Good luck.

[JBsurfin]

Originally Posted by Barkingmad

There is no one magic product, I use what is appropriate for the job. Sometimes butyl sometimes something else. About the only one that has NO place on MY boat or my house is silicone.

[Exile]

Originally Posted by JBsurfin

My chain plates come through the deck on my 83 Dickerson Ketch. I packed the tape into the hole around the chain plate and then placed it flat to the deck and replaced my cover plate that screws down, adding compression. After a couple of days, retighten the screws a bit, wait another day and used a razor knife to cut back the excess. Been that way for 5 yrs now, no leaks. As noted, get quality tape.

Maybe you already do this, but Mainesail also recommends chamfering/countersinking the screw/bolt holes in the deck itself and then put a thinly rolled piece of butyl around the inside. That way the butyl seals the top of the tapered bolt head.

One question: It seems as though any butyl not covered by the plate erodes & hardens due to exposure/UV. What about the gap between the edges of the chain plate and the cover plate where butyl is exposed? Perhaps something like 3M UV4000 would be a better choice here?

[col50]

Originally Posted by davil

another use
recently bedded the depth finder transducer inside. Just sanded the area to a good, smooth surface, cut out some tape, rounded on my hands to a ball and pressed the transducer, perfect sealing, no air bubbles, good transmission.
No messy silicone, or epoxy, easily removed good stuff.

I have done the same, and it works well.