Is Butyl Tape Still Recommended??

[N-Aimless]

I just finished a yard haul out at Ram Marine in Rio Dulce, Guatemala. The primary project was a complete refinishing of the boat from the water line up including the decks and cockpit with new gel coat. This required the removal of all the deck fittings and hardware. I flew to Fort Lauderdale specifically to pick up materials for the haul out that are not available in Guatemala. Particularly re-bedding materials. I purchased two rolls of Bed-It Butyl Tape from Compass Marine (compassmarineservices@gmail.com). They have a terrific website (MarineHowTo.com) with instructions and product recommendations on several maintenance subjects including the proper use of butyl tape. The site has links to purchase the referred to products. I did all of the re-installations myself. With zero leaks (and boy does it rain in Rio). I've never had that success rate with caulkings. AND the Bed It Tape is very easy to clean up and the excess clean up material can be reused. Actually I should have bought at least on more roll. I wound up using some Amazon butyl tape that I had in stock. There was a striking difference between the two products. I had also purchased a number of caulking tube of BoatLife and Sikaflex. I wound up only using the Sikaflex UV for bedding the new Lexan for the skylight hatches.

[JBsurfin]

Originally Posted by Exile

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?

Since I placed the tape flat to cover the entire spacing of the cover plate, (sorry, no picture to show) the screws go thru the tape pulling it into the treads and the compression oozes out a bit. in the 5 yrs its been done, I can still ply it with a finger nail. I haven't seen any erosion. Did the exposed edge harden a bit with a crust, yes, but pliable with a finger indicating its not dried out.

[Exile]

Originally Posted by JBsurfin

Since I placed the tape flat to cover the entire spacing of the cover plate, (sorry, no picture to show) the screws go thru the tape pulling it into the treads and the compression oozes out a bit. in the 5 yrs its been done, I can still ply it with a finger nail. I haven't seen any erosion. Did the exposed edge harden a bit with a crust, yes, but pliable with a finger indicating its not dried out.

OK, good to know thanks. I've had similar success using MaineSail's butyl tape. The only exception was where a fitting or cover provided insufficient compression, but that was my error.

[JBsurfin]

Originally Posted by Exile

OK, good to know thanks. I've had similar success using MaineSail's butyl tape. The only exception was where a fitting or cover provided insufficient compression, but that was my error.

I use tape on my chainplates, cabin head hatches, general ports and deck fittings where compression takes place. Even with caulking, always remember to not fully tighten, let it setup and then come back to re-tighten. Otherwise you just squeeze it all out.

[GreenWave]

Originally Posted by 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.

Excellent idea and I have a project this weekend where this approach might be needed.
Thanks for lighting the bulb!

[R Hutcheson]

I've had good luck with quality Butyl Tape. I have always suspected the unwillingness of boat yards to use it is a matter of labor time. You have to clean and prep the area well with either Butyl or 4200. But with 4200 you put everything together and you're done. With Butyl, you tighten a bit, come back the next day tighten a little more, and so on for a few days. It simply takes more time to get it right.

[sailorxyz]

Been using Butyl tape for 30 years... I have found it to be utterly reliable. Yes it does ooze a bit under some conditions. However I prefer a bit of oozing to leaks.... the excess is no problem to clean up.

[merrydolphin]

I have used tape for 10 yrs now. No problems and sooooooo much better to work with. I say that but I do use a marine grade tape. Love it.

I thinks that it works best on flatter surfaces like a cleat to a deck. Or scansion base. The only thing that can bother it is fuel. Don’t spill or submerge it in fuel. A little spill wont hurt but not regular exposure. I would not use it to bed a furl fill fitting for example.

[Kiwi Dave]

Hi all

I have used butyl in a caulking tube for decades for sealing under fittings - yes it goes everywhere, cleans with any thinners from turps upward. it does stick like sh** to a blanket. Use 291 if I want an adhesive sealant, but can remove the paint when removing the fitting.

[s3raphim]

All of the windows on my Cal 39 are bedded with butyl tape, and in 10 years haven't seen a single leak. Also recently bedded two on-deck vents (chimney and hot water) with butyl tape... also no leaks, or significant oozing.

[elandra65]

I absolutely love Butyl tape and use it as much as possible. They should make a law requiring a licence to use polyurethane adhesives! If you ever have had to remove hatches, portlights or just about any other fitting the boat builder or previous owner stuck down with Poly you know what I mean.

There are many advantages to Butyl tape but the ability of it to retain a waterproof seal for many years irregardless of flexing such as staunchion mounts is unsurpassed. It has an amazing ability to retain a seal even with large movement. I have used it for all my deck fittings including hatches and portlights and never had a leak. It is important though to understand the product and prepare it properly including cleaning, countersinking holes to maximise volume of butyl and particularly tightening the fitting which preferably requires a few stages. I have even used it to seal a new sounder thru hull with the boat sitting in the slings for half an hour. No wait time required at all before you get a waterproof seal. It is more time consuming than just slapping on some sealant but the end result is much better. Be aware though that Butyl has no strength and is not an adhesive at all. Rather a very very elastic non hardening sealant that sticks like poo to a picknick rug. Another significant advantage is that the shelf life is virtually unlimited unlike like poly which must be used within a short time of opening with a very limited shelf life for unopened cartidges. You also have as much working time as you like.

See:

https://www.sailnet.com/threads/bedd...yl-tape.63554/

An Ode To Butyl Rubber - Life On The Hook

good luck

Andrew

[bbalan]

Hi All,
We did a total refit of our 1969 Cross 46' glass over ply trimaran in Thailand in 2013/14. We took every single piece of equipment off. Anything that was thru-bolted was put back on with Compass Marine butyl... that's over 120 pieces of hardware including hatches (12), winches, jib track, clutches, mast step, turning blocks, ports, portlights, chainplates etc.


Since the refit we've sailed about 20,000 miles from the tropics to the Aleutians.


Only one piece of hardware has leaked -- the forestay chainplate -- and that was because of installation error.


If anything is thru-bolted on Migration, we use butyl from Compass Marine. It's easy to clean, you have all the working time you want, and it lasts. You can even reuse some of it if it's clean! We just removed our outer jib/spinny tracks to file some drain holes. These tracks take lots of load. Not a trace of water anywhere under the track after 8 years of hard sailing and big temperature swings -- and water pooling against the edge (thus the drain holes!). And the cleanup is so much easier than other products! (Turpentine is the best).



Thanks Rod for an awesome product!
Cheers,
Bruce
s/v Migration

[Jerry Woodward]

Originally Posted by s3raphim

All of the windows on my Cal 39 are bedded with butyl tape, and in 10 years haven't seen a single leak. Also recently bedded two on-deck vents (chimney and hot water) with butyl tape... also no leaks, or significant oozing.

This is the first I've heard of using butyl tape for windows. Are they acrylic? This sounds like an easier and neater method than using silicone. Did you use screws for fasteners? Can you suggest any further reading on using butyl tape for windows?