Best port caulk???

[Lee Scott]

Finally we get some rain here in the South! And I've discovered that a couple of the ports leak in my new '87 Catalina 27. :-( The worst leaking one had obviously been worked on at some point in the past, and had been re-caulked with clear RTV silicone. I've removed the port and cleaned off all the silicone, and I'm now ready to reinstall the port.Is clear silicone the best caulk to use?

 

[Lee Scott]

Finally we get some rain here in the South! And I've discovered that a couple of the ports leak in my new '87 Catalina 27. :-( The worst leaking one had obviously been worked on at some point in the past, and had been re-caulked with clear RTV silicone. I've removed the port and cleaned off all the silicone, and I'm now ready to reinstall the port.Is clear silicone the best caulk to use?

 

[Rick Sylvester]

Probably not, however

it'll depend on how your port is attached. Silicone has very poor adhesive qualities but remains pliable after it cures so that it forms a good gasket material that will seal well if slightly compressed by a through-bolted port frame. If you've got plastic ports that rely on screws and a cover ring then silicone would be a poor choice unless you use a structural silicone like GE's SSG4000 Ultraglaze. I've only seen it in black. I used it to rebed the lenses in my hatches.For sealing my deck hardware I still rely on 3M's 101 polysulfide. It adheres well, remains pliant, is easily removed when necessary and comes in black or white.I think Lifeseal is a polysufide/silicone blend which provides qualities of both. I don't use it so I can't comment.Hope this helps.

 

[Rick Sylvester]

Probably not, however

it'll depend on how your port is attached. Silicone has very poor adhesive qualities but remains pliable after it cures so that it forms a good gasket material that will seal well if slightly compressed by a through-bolted port frame. If you've got plastic ports that rely on screws and a cover ring then silicone would be a poor choice unless you use a structural silicone like GE's SSG4000 Ultraglaze. I've only seen it in black. I used it to rebed the lenses in my hatches.For sealing my deck hardware I still rely on 3M's 101 polysulfide. It adheres well, remains pliant, is easily removed when necessary and comes in black or white.I think Lifeseal is a polysufide/silicone blend which provides qualities of both. I don't use it so I can't comment.Hope this helps.

 

[Frank15180]

beckson installation

The ports in the chandlery have online instructionslink below for beckson and this one for pompanette.http://www.pompanette.com/pompweb.nsf/a0e2253b23a1a536852567ae003c83a9/e2a22a36069c0db285256846005c0a41?OpenDocumentSikaflex® -295 UV  Sikaflex®-295 UV is a fast curing, one-component, flexible, high performance polyurethane-based adhesive for bonding and sealing of windows and portholes. Sikaflex®-295 UV is suitable for all types of organic (PC, PMMA) windowpanes. Its high degree of UV resistance also allows the use of the system as a weatherproof sealant.

 

[Frank15180]

beckson installation

The ports in the chandlery have online instructionslink below for beckson and this one for pompanette.http://www.pompanette.com/pompweb.nsf/a0e2253b23a1a536852567ae003c83a9/e2a22a36069c0db285256846005c0a41?OpenDocumentSikaflex® -295 UV  Sikaflex®-295 UV is a fast curing, one-component, flexible, high performance polyurethane-based adhesive for bonding and sealing of windows and portholes. Sikaflex®-295 UV is suitable for all types of organic (PC, PMMA) windowpanes. Its high degree of UV resistance also allows the use of the system as a weatherproof sealant.

 

[Maine Sail]

I'll second 3M 101

I too like 3M 101 but Sikaflex is my sealant of choice these days..

 

[Maine Sail]

I'll second 3M 101

I too like 3M 101 but Sikaflex is my sealant of choice these days..

 

[Lee Scott]

Thanks,

My ports are just tinted plastic held into the factory moulded recesses in the cabin trunk by perimeter screws. There is no trim ring or frame.The silicone seems to stick pretty well to the gelcoat on the boat. It didn't bond well at all to the lexan or whatever the port itself is made of. I've gotten all of silicone off the port. but the recessed frame seems to retain a thin layer bonded to the gellcoat no matter how much I scrape it. Is it necessary to completely remove all traces of the silicone before rebonding the port with Sikaflex? If so, is there anything that will soften or dissolve the silicone, or do I just need to keep on scraping???

 

[Lee Scott]

Thanks,

My ports are just tinted plastic held into the factory moulded recesses in the cabin trunk by perimeter screws. There is no trim ring or frame.The silicone seems to stick pretty well to the gelcoat on the boat. It didn't bond well at all to the lexan or whatever the port itself is made of. I've gotten all of silicone off the port. but the recessed frame seems to retain a thin layer bonded to the gellcoat no matter how much I scrape it. Is it necessary to completely remove all traces of the silicone before rebonding the port with Sikaflex? If so, is there anything that will soften or dissolve the silicone, or do I just need to keep on scraping???

 

[Maine Sail]

We did not know..

We did not know the ports were "plastic" and many of the products like polyurethanes from 3M4200 & Sikaflex 291/295 should be used with caution. 3M 101 is a polysulfide and should not be used on plastics. Call Catalina and ask what they use to bed plastic portlights??

 

[Maine Sail]

We did not know..

We did not know the ports were "plastic" and many of the products like polyurethanes from 3M4200 & Sikaflex 291/295 should be used with caution. 3M 101 is a polysulfide and should not be used on plastics. Call Catalina and ask what they use to bed plastic portlights??

 

[Tricia]

Dow Corning 795...

is a structural silicone used to bed windows in commercial buildings. I used it to bed the frameless plexi windows in my Freedom 25 3 yrs ago and it's holding well. Bonus: it's really inexpensive and comes in several colours. You should be able to find it an an industrial building supplier. Silicone, to my knowledge, is the only sealant that's compatible with acrylic.If you decide to go with the Sika 295, be sure to use the primer as it won't stick without it. Don't ask me how I know. It's also very stiff to work with.Good luck!Tricia

 

[Tricia]

Dow Corning 795...

is a structural silicone used to bed windows in commercial buildings. I used it to bed the frameless plexi windows in my Freedom 25 3 yrs ago and it's holding well. Bonus: it's really inexpensive and comes in several colours. You should be able to find it an an industrial building supplier. Silicone, to my knowledge, is the only sealant that's compatible with acrylic.If you decide to go with the Sika 295, be sure to use the primer as it won't stick without it. Don't ask me how I know. It's also very stiff to work with.Good luck!Tricia

 

[Lee Scott]

ACRYLITE GP is what I've got

I found a spare window that was still covered with the protective paper, and it's a product called ACRYLITE GP. As an acrylic, I assume silicone the best thing to use, as long as I use an industrial strength version and not the generic stuff you get at Home Depot?

 

[Lee Scott]

ACRYLITE GP is what I've got

I found a spare window that was still covered with the protective paper, and it's a product called ACRYLITE GP. As an acrylic, I assume silicone the best thing to use, as long as I use an industrial strength version and not the generic stuff you get at Home Depot?

 

[NorfolkRagbagger]

The Cure for Port Caulk leaks

Whatever caulk you use, the ports will leak - I think it's the 39th law of thermodynamics or something like that. The 40th law of thermodynamics is that the worst leak will be over your bunk. New caulk will work for a time, then get out the buckets again. I've accepted that in my 40 years of owning a boat, until this past August.The cure for the leaks you can't find is Capt. Tolley's Creeping Crack Cure. I've retired one-five gallon and two-two gallon pails since using this stuff. It's easy to use, works unbelievably well .. don't leave port without it.No, I don't work there or own stock in them. Wish I did. It's the best invention for a boat since the blow-up sheep.

 

[NorfolkRagbagger]

The Cure for Port Caulk leaks

Whatever caulk you use, the ports will leak - I think it's the 39th law of thermodynamics or something like that. The 40th law of thermodynamics is that the worst leak will be over your bunk. New caulk will work for a time, then get out the buckets again. I've accepted that in my 40 years of owning a boat, until this past August.The cure for the leaks you can't find is Capt. Tolley's Creeping Crack Cure. I've retired one-five gallon and two-two gallon pails since using this stuff. It's easy to use, works unbelievably well .. don't leave port without it.No, I don't work there or own stock in them. Wish I did. It's the best invention for a boat since the blow-up sheep.

 

[jcherubini]

5200

For portlights and ALL hardware being bolted down, use 5200-- or its low-strength high-yield sibling, 4200. These are structural as well as waterproof, pliant, and permanent, needing little or no attention for 10 years at least (or, in the case of my black aluminum toerail, 34 years).This is a job for poly, not silicone. Silicone, in the words of Dave Cherubini, 'has no place in the marine environment. It's for the bathtub environment.' (And, really, not even for that!)I have typically peeled up fittings bedded in silicone only to find black mold under them, from where the water had been trapped for years after the silicone let it in so it could rot the core underneath.Be sure to clean ALL the silicone residue off and out before applying a poly bedding compound. This is the other nightmarish legacy of silicone-- it never truly works, and almost never goes away.

 

[jcherubini]

5200

For portlights and ALL hardware being bolted down, use 5200-- or its low-strength high-yield sibling, 4200. These are structural as well as waterproof, pliant, and permanent, needing little or no attention for 10 years at least (or, in the case of my black aluminum toerail, 34 years).This is a job for poly, not silicone. Silicone, in the words of Dave Cherubini, 'has no place in the marine environment. It's for the bathtub environment.' (And, really, not even for that!)I have typically peeled up fittings bedded in silicone only to find black mold under them, from where the water had been trapped for years after the silicone let it in so it could rot the core underneath.Be sure to clean ALL the silicone residue off and out before applying a poly bedding compound. This is the other nightmarish legacy of silicone-- it never truly works, and almost never goes away.