Removing butyl tape bedding

[Blue Streak]

I am rebuilding the portlights (deadlights) in my E25 with the Catalina kit, after having tried to just rebed them with butyl tape.

Any suggestions as to how to clean off the old butyl tape?

 

[Alan Gomes]

Butyl tape can be helpful in removing butyl tape. Roll up some butyl in a ball and use it to remove the butyl off of the surface.

By the way: I'm becoming less and less a fan of the stuff. I've also concluded it's not the weapon of choice for bedding portlights. I'm here talking about the seal between the aluminum frame and the exterior cabin sides. I much prefer Sikaflex 291 for that task.

 

[bigd14]

Any suggestions as to how to clean off the old butyl tape?

Try paint thinner or mineral spirits.

 

[Blue Streak]

Butyl tape can be helpful in removing butyl tape. Roll up some butyl in a ball and use it to remove the butyl off of the surface.

By the way: I'm becoming less and less a fan of the stuff. I've also concluded it's not the weapon of choice for bedding portlights. I'm here talking about the seal between the aluminum frame and the exterior cabin sides. I much prefer Sikaflex 291 for that task.

I have tried that, with limited success. It really sticks to aluminum!

 

[Christian Williams]

Caution with Sikaflex 291. Use LOT (Long Open Time). Make sure tubes are less than a year old. Tape carefully, it resists cleanup. I learned why they say "professional use only".

I'd say Life-calk is a better choice for portlight bedding. I used 291 to bed rub rails and it was not easy to work with.

 

[Bepi]

I have had great results cleaning tar-like residue off hands and surfaces with paraffin lamp oil.

 

[klb67pgh]

I agree butyl to remove butyl.

I removed and rebed the port side deadlights on my E25 this off season, and used Sikaflex 291. I taped carefully, did one window at a time, had a helper in the boat to start the hardware and help manage the window, and was very pleased with the results. I will do the starboard side this off season (it fixed a small leak I had on the port side and I ran out of time to do the starboard side). I used a life caulk polysulfide for the rub rail plastic extrusion 2 years ago and am not pleased with its longevity - it has discolored. I have otherwise liked their products too and maybe this was an anomaly.

 

[Alan Gomes]

Caution with Sikaflex 291. Use LOT (Long Open Time). Make sure tubes are less than a year old. Tape carefully, it resists cleanup. I learned why they say "professional use only".

I'd say Life-calk is a better choice for portlight bedding. I used 291 to bed rub rails and it was not easy to work with.

Interesting observations about Sikaflex 291.

Personally, I found one of the charms of it, compared to a polysulfide caulk like 3M-101 (or the polysulfide Boatlife equivalent they are selling these days), is how easily it cleaned up by comparison. With the polysulfide caulks, just looking at a tube of it makes a mess, and cleanup is really difficult. I found the Sikaflex cleans up easily with acetone--before it sets up, obviously. I've been able to get a very neat result with it.

Fun fact: I just used the stuff about 2 hours ago to bed a piece of hardware. And I agree with the issue about the value of using newer tubes. My tube was maybe a year old (don't remember exactly), and sealed as best as I knew how. I had a heck of a time punching my way through the hardened sealant at the top to get out remaining sealant to use for this small job. I've again taped off the tube but don't hold out high hopes for what might happen to it.

 

[Alan Gomes]

I agree butyl to remove butyl.

I removed and rebed the port side deadlights on my E25 this off season, and used Sikaflex 291. I taped carefully, did one window at a time, had a helper in the boat to start the hardware and help manage the window, and was very pleased with the results. I will do the starboard side this off season (it fixed a small leak I had on the port side and I ran out of time to do the starboard side). I used a life caulk polysulfide for the rub rail plastic extrusion 2 years ago and am not pleased with its longevity - it has discolored. I have otherwise liked their products too and maybe this was an anomaly.

Very interesting.

Right now I'm in the process of putting Formica on my cabin sides to cover up the water-damaged and delaminated wood. Early in the process I removed all the trim rings on the windows.

Earlier, I had bedded one of the fixed ports and the forward opening port, port side, with butyl. I bedded all the other ports with Sikaflex 291 (i.e., after deciding I hated using butyl for that job on those other two). It turns out that the windows bedded with butyl were relying on the trim ring to hold them in place. Without the trim rings, the top forward edge of the windows separated from the cabin sides and I can now see daylight through them--obviously anything but water tight! I'm thinking that maybe the warm temps we've had here in the last month softened up the butyl and it just let go its grip. The windows bedded with Sikaflex are still solidly in place. For the Sikaflex windows, the trim rings hold the windows in place while the sealant dries, but the sealant itself has enough adhesive strength to not rely on the trim rings beyond the initial cure phase.

Once I'm done with the Formica job, I'll remove those windows I installed with butyl, clean up the mess, and re-install them with the Sikaflex.

As for removing a window bedded with 291: I have had to do that, to repair one of the windows that still leaked. (The leak was not between the flange and the cabin sides, bedded with the 291, but internally in the window itself.) The 291 is tenacious, but it's not like 5200, either. I didn't find it too terribly hard to remove, but harder than something set with butyl.

 

[reginaldobaker]

I recently dealt with removing old and reapplying new butyl tape and what worked best for me was as follows:

- clean up big pieces by hand and/or with chisel or flathead screw driver (gently)
- further remove smaller pieces using a "ball" of butyl and dabbing
- remove last bits of butyl residue using alcohol/acetone and a "wooden q-tip" (from Harbor freight); applying pressure in circular motions while twisting the swab worked very well and gave a clean finish

 

[G Kiba]

Plastic scrapers are wonderful. The kind they sell for cleaning cooked food off pots and pans. You will never scratch the aluminum or gel-coat by mistake.

 

[peaman]

Plastic scrapers are wonderful.

West System "mixing sticks" are great for use where space is limited.

 

[Loren Beach]

Plan B (or C) is to pick up some 1/4" acrylic pieces from a local plastics supply house scraps bin. Cut a 45 degree edge on one side of a short piece and sand it to a sharp "edge". slightly dull the corners to prevent digging in. Sort of like a small version of those plastic ice scrapers you can buy for windshields at the auto parts store.
Plan D: the shop that did our re-fit would keep some little one inch pieces of Oak (or other scrap hardwood) around for constant "resharpening" for just this purpose. Worked very well.

 

[G Kiba]

Always been meaning to try these plastic single edge razor blades.

 

[p.gazibara]

Butyl tape can be helpful in removing butyl tape. Roll up some butyl in a ball and use it to remove the butyl off of the surface.

By the way: I'm becoming less and less a fan of the stuff. I've also concluded it's not the weapon of choice for bedding portlights. I'm here talking about the seal between the aluminum frame and the exterior cabin sides. I much prefer Sikaflex 291 for that task.

DOW 795 neutral cure silicone is probably the best product for sealing deadlights. It's what the kiwi boatbuilders use. I used it on all my portlights/deadlights back in 2020. Like Sika 291 (unlike 3m products) the bead is thick and stays where you put it, it was designed to seal glass to aluminum frames in highrise buildings. I used it to seal the aluminum frames to the cabinsides. Easy to use, if taped, the tape can be pulled before full cure leaving neatly coved edges. Very flexible, a trait needed on the cabinside of the E boats (they are qute thin and flex easily).

I found after removing all the portlights/deadlights that my aluminum farmed deadlights actually stiffened the cabinsides. During the process of fixing the portlight leaks, I bonded 4mm ply to 10mm boatbuilding foam and glued that to the inside of the cabinsides to remove the need for the alluminum fames to stiffen the cabinsides. The boat is better insulated now, and I'm less worried about leaks due to cabinside flex.

I believe I saw a post where Alan? Glued the fiberglass headliner to the cabinsides to help stiffen them. I would have done that, but instead opted to cut the fiberglass headliner out completely. Cinderella previously had cabin liner cut out in a big refit back in the 90's. When I bought her she was nearly a bare hull inside with PO adding reinforcement of the grid, and other key areas to prevent oil canning and stiffen her up.

Now I can see where the leaks were are coming from... Big job though, spent a week in a tyvek bunny suit cutting through fiberglass overhead with a grinder. Never want the pleasure of that experience again if I can help it.

Not all butyl is the same, ask me how I know, lol. I have not had luck with butyl, apparenty I bought a bad batch or something, has put me off from using it ever since. I hate redoing jobs I just did.

We recently had a look at Whidby 42 here we were considering moving up to. It was also done with butyl back in 2017 and lets just say we passed on the boat after seeing all the water damage from the leaks. Maybe everything just needs to be retightened after you cross an ocean with butyl since it relies on the fasteners to keep the seal?

 

[Alan Gomes]

I believe I saw a post where Alan? Glued the fiberglass headliner to the cabinsides to help stiffen them. I

Not I. (My boat has a vinyl headliner.)

 

[Alan Gomes]

DOW 795 neutral cure silicone is probably the best product for sealing deadlights.

I agree that Dow 795 is good stuff. I used it on my previous boat, that had acrylic portlights bonded directly to the cabin sides without frames. Now that you brought it up, I'm not sure why it didn't occur to me to use it here. But the Sikaflex 291 has done a good job for me and I'm satisfied with it.

 

[Loren Beach]

FWIW, our 4 external lenses were adhered with Sikaflex 295UV. I have a blog entry showing the process, which did require a primer.

 

[maubin5]

Butyl tape can be helpful in removing butyl tape. Roll up some butyl in a ball and use it to remove the butyl off of the surface.

By the way: I'm becoming less and less a fan of the stuff. I've also concluded it's not the weapon of choice for bedding portlights. I'm here talking about the seal between the aluminum frame and the exterior cabin sides. I much prefer Sikaflex 291 for that task.

Just rebedded the 4 big portlights, I was going to use Dow 795 but changed my mind at the last minute and used 3m4000. I’ll post feedback down the road

 

[bsangs]

Always been meaning to try these plastic single edge razor blades.
View attachment 47904

I used those this past winter to remove lots of stubborn adhesive residue. Paired with Goo Gone, they made a wonderful couple.