I forgot to mentioned that the opening ports I bought from Bomar were plastics.I contacted two reputable marine installers. One wanted to use 5200, the other 101 polysulfide. West Marine catalogue doesn't recommend using 101 on plastic.These guys are suppose to know what to use. Repeat business depend on them using the right product to do a good job! I got the plastic windows from Mark Plastic and he recommended GE silicon. Can I use that product for the ports also.I can't afford to have to redo this job in 5 years because the wrong product was use.Both these guys refuse to warrentee the job unless I use the product they recommended. I have to get this job done by next Friday. Most of you recommended Dow Corning 795, but you didn't tell me what properties this product contains that made you decide this was the best choice.Around here nobody has ever heard of 795. I appreciate the advice you all have given me .I wish I would of known about this forum sooner. I could of saved myself a lot of headaches and money. Thanks
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I have used Life Caulk successfully.
Denise, I replaced 3 ports on my boat. Not just the lenses, but the whole port. Once I had removed the screws and the whole port, I resealed the the new ones with Life Caulk and replaced the screws. It doesn't harden rock-solid, but cures to a flexible stage. From the tube, it has the consistency of tooth paste and can be messy to work with. Keep paper towels nearby. It has worked successfully for me for several years.
Denise, I replaced 3 ports on my boat. Not just the lenses, but the whole port. Once I had removed the screws and the whole port, I resealed the the new ones with Life Caulk and replaced the screws. It doesn't harden rock-solid, but cures to a flexible stage. From the tube, it has the consistency of tooth paste and can be messy to work with. Keep paper towels nearby. It has worked successfully for me for several years.
Installing Plastic ports
Denise, I recently installed 11 new Gray opening portlights in my 79 H33 and used white GE Silicone II for bath. this is a readily available caulk from most any building supply. Like you, I agonized over the correct caulk and came up with the GE Silicone II for bath (it is mildew resistant) for the following reasons: 1. The port manufacturer said use silicone only. A label affixed to the port itself gave this very explicit mandate. 2. The boat caulks 5200-4200 gun very poorly compared to the GE silicone II. 3. Hunter had used a kind of silicone (may be the Dow corning 795) and the ports remained well sealed for over 20 years. 4. I was able to remove the ports sealed with the original silicone fairly easily. Rest assured this would not be the case sealed with 5200 5. The silicone is pretty much impervious to uv. Not so with 5200 which chalks quickly. For the Gray ports there is left exposed a line of caulk between the trim ring and the barrel so uv resistance is not trivial. Also, you may want to check the Photo forum for an article with photos of installation I posted in the last month or so.
Denise, I recently installed 11 new Gray opening portlights in my 79 H33 and used white GE Silicone II for bath. this is a readily available caulk from most any building supply. Like you, I agonized over the correct caulk and came up with the GE Silicone II for bath (it is mildew resistant) for the following reasons: 1. The port manufacturer said use silicone only. A label affixed to the port itself gave this very explicit mandate. 2. The boat caulks 5200-4200 gun very poorly compared to the GE silicone II. 3. Hunter had used a kind of silicone (may be the Dow corning 795) and the ports remained well sealed for over 20 years. 4. I was able to remove the ports sealed with the original silicone fairly easily. Rest assured this would not be the case sealed with 5200 5. The silicone is pretty much impervious to uv. Not so with 5200 which chalks quickly. For the Gray ports there is left exposed a line of caulk between the trim ring and the barrel so uv resistance is not trivial. Also, you may want to check the Photo forum for an article with photos of installation I posted in the last month or so.
Call Hunter!
Denise: I would call Hunter. I believe that the original product was the DOW 795 product. You can get it from them. We have NEVER needed to redo a port and it is the original product. Regardless of what anyone says, if you use 5200 you may not be able to remove a port wheather or not you want to. 5200 would be MY last choice. I personally like the Life Caulk products, but you need to get the product that will work with the parts that you are working with. DOW 795 is a commercial sealant. Not easy to find but it is a top quality product.
Denise: I would call Hunter. I believe that the original product was the DOW 795 product. You can get it from them. We have NEVER needed to redo a port and it is the original product. Regardless of what anyone says, if you use 5200 you may not be able to remove a port wheather or not you want to. 5200 would be MY last choice. I personally like the Life Caulk products, but you need to get the product that will work with the parts that you are working with. DOW 795 is a commercial sealant. Not easy to find but it is a top quality product.
Conflicting Advice Can Be Difficult
Don't feel bad as I'm sure all of us have been through - ask a question and get a lot of conflicting advice. If it's a Hunter boat I'd second the suggestion to call Hunter if you're unsure about what to do. Hunter uses 795 and also sells it. As for a suggestion on the install, though, I'd recommend filing or grinding the outside of the opening at about a 45-degree angle to enable a larger bead of sealant between the port and the coach roof. For a cleaner job try to tape some plastic on the inside of the coach roof and before removing it vaccuum up the dust otherwise all the dirt will get inside the liner. The trim ring of the port has a 45-degree angle where it faces the coach roof and what you'd be doing it making a mirror image of this on the coach roof opening. The end result is more room for the sealant bead. Pay special attention to the sealant applied at the bottom of the port, especially where the drip spouts are, as it is easy to have a poor seal there. Don't put sealant on the inside of the boat (liner) as all this will do is make it harder to remove the port should this ever become necessary. By the time water has got this far it is too late anyway. It's a long, messy job but not rocket science. New ports really make the boat look great from the inside.
Don't feel bad as I'm sure all of us have been through - ask a question and get a lot of conflicting advice. If it's a Hunter boat I'd second the suggestion to call Hunter if you're unsure about what to do. Hunter uses 795 and also sells it. As for a suggestion on the install, though, I'd recommend filing or grinding the outside of the opening at about a 45-degree angle to enable a larger bead of sealant between the port and the coach roof. For a cleaner job try to tape some plastic on the inside of the coach roof and before removing it vaccuum up the dust otherwise all the dirt will get inside the liner. The trim ring of the port has a 45-degree angle where it faces the coach roof and what you'd be doing it making a mirror image of this on the coach roof opening. The end result is more room for the sealant bead. Pay special attention to the sealant applied at the bottom of the port, especially where the drip spouts are, as it is easy to have a poor seal there. Don't put sealant on the inside of the boat (liner) as all this will do is make it harder to remove the port should this ever become necessary. By the time water has got this far it is too late anyway. It's a long, messy job but not rocket science. New ports really make the boat look great from the inside.
Caution
The sealant generally referred to as "Life Caulk" or "Boat Life" is a polysulfide. Polysulfide sealants will attack some plastics which include the portlights made by Gray. They attack the plastic very slowly and soften it which adversely affects its engineering properties. The 3M products (5200 and 4200) are polyurethanes. They (as well as the silicones)generally do not attack plastics but subsequent disassembly can be very difficult. Silicones make ok sealants in a lot of circumstances but they are generally not very good adhesives. That's where the 3M's really shine. btw: Polysulfides were first developed by Morton Thiokol. They are the folks that built the space shuttle booster rocket o-ring seals that failed on the disastrous Challenger flight.
The sealant generally referred to as "Life Caulk" or "Boat Life" is a polysulfide. Polysulfide sealants will attack some plastics which include the portlights made by Gray. They attack the plastic very slowly and soften it which adversely affects its engineering properties. The 3M products (5200 and 4200) are polyurethanes. They (as well as the silicones)generally do not attack plastics but subsequent disassembly can be very difficult. Silicones make ok sealants in a lot of circumstances but they are generally not very good adhesives. That's where the 3M's really shine. btw: Polysulfides were first developed by Morton Thiokol. They are the folks that built the space shuttle booster rocket o-ring seals that failed on the disastrous Challenger flight.
Jim
I'm not launching a rocket
but selected lifecaulk on my '88 Legend because that's what I thought I saw when I removed the old port. It was white caulking, but not like a 5200. Is the Dow white? Anyway, I replaced the first one 4 years ago and things still look OK. Hopefully they are fine. This is all more food for thought. Thanks for the advice.
I'm not launching a rocket
but selected lifecaulk on my '88 Legend because that's what I thought I saw when I removed the old port. It was white caulking, but not like a 5200. Is the Dow white? Anyway, I replaced the first one 4 years ago and things still look OK. Hopefully they are fine. This is all more food for thought. Thanks for the advice.Look at the Dow Corning Site.
Dow Corning has a good site about their products. www.dowcorning.com You can look up the products and find dealers too. You can search on the different products and get detailed product information.
Dow Corning has a good site about their products. www.dowcorning.com You can look up the products and find dealers too. You can search on the different products and get detailed product information.
I had the same questions
I had the same questions you have when I rebed my ports -- and got the same conflicting advice. I was able to reuse my old ports but called Beckson, a major port manufacturer, and they were specific about using only 100% silicon. I also called 3M, and they were just as adament that I should use 101. I could not get credible advice to break the tie, so used silicone on one side of the boat and 101 on the other. I hope I don't ever find out which is better. The silicone went on easier and you can neaten the bead and clean up with just a water-wet rag before it sets up. So far both have kept the rain out fine. The only definite I can think of is don't use 5200. I did have to re-do one of mine, which would be impossible with 5200.
I had the same questions you have when I rebed my ports -- and got the same conflicting advice. I was able to reuse my old ports but called Beckson, a major port manufacturer, and they were specific about using only 100% silicon. I also called 3M, and they were just as adament that I should use 101. I could not get credible advice to break the tie, so used silicone on one side of the boat and 101 on the other. I hope I don't ever find out which is better. The silicone went on easier and you can neaten the bead and clean up with just a water-wet rag before it sets up. So far both have kept the rain out fine. The only definite I can think of is don't use 5200. I did have to re-do one of mine, which would be impossible with 5200.
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