Correct Sealant?

Discussion in 'Sport Cruisers' started by Barlow1016, May 9, 2019.

  1. Barlow1016

    Barlow1016 Member

    45
    Jun 3, 2017
    Farmington Utah
    1999 340 Sundancer
    454 merCruiser 7.4 MPI Bravo one outdrive’s 4 blade props. 5.0 Westerbeke generator
    What would be the correct sealant to seal between my arch and the side of my boat?And what about to re-bed my porthole windows and my hatch covers?I see 3M offers a couple of good products, 4200, but it’s not UV resistant and then 4000 and it is UV resistant.What about other brands? Any idea what they use OEM from the factory? I want to do this correctly one time and don’t want it to rub off like crappy silicone. Any input much appreciated.
     
  2. Barlow1016

    Barlow1016 Member

    45
    Jun 3, 2017
    Farmington Utah
    1999 340 Sundancer
    454 merCruiser 7.4 MPI Bravo one outdrive’s 4 blade props. 5.0 Westerbeke generator
    Also what about the bottom side of the rub rail. As I was polishing the boat I noticed a lot of this sealant is needing to be redone.
     
  3. MonacoMike

    MonacoMike Well-Known Member PLATINUM Sponsor

    Sep 15, 2009
    Indiana lakes and Lake Michigan
    2000 Cruisers 3870
    8.2 Mercs
    85 Sea Ray Monaco 197
    260hp Alpha 1
  4. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    4000UV is fine. I personally prefer the BoatLife products - I'd go with LifeSeal in this case, but LifeCaulk is by no means a poor choice. Get rid of the sealant on the underside of the rubrail base (and on top, too) - it's worthless. FYI, it was never there from the factory.
     
  5. MonacoMike

    MonacoMike Well-Known Member PLATINUM Sponsor

    Sep 15, 2009
    Indiana lakes and Lake Michigan
    2000 Cruisers 3870
    8.2 Mercs
    85 Sea Ray Monaco 197
    260hp Alpha 1
    So you would have recommended LifeSeal for the porthole Windows?

    MM
     
    marty51 likes this.
  6. Korkie

    Korkie Active Member GOLD Sponsor

    580
    Feb 2, 2016
    Leonardtown, MD Potomac River / Chesapeake Bay
    340 Sundancer 2006, Garmin 7612, xHD Radome
    Merc 496 Mags
    Bravo III Drives
    Just used LifeSeal on the same areas. Very easy to work with, UV resistant and came out really nice. Picked the LifeSeal after going through several threads on hear. Since I am less than a novice caulker - I masked out with painters tape. pulled it off a couple of minutes after placing caulk. Quite satisfied with the final outcome.
     
  7. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    Not necessarily. The primary advantage of LC is strength, but the strength really isn't needed in this application. The downside to LC is that it's messy and harder to tool. LS tools much easier. I've used both in these types of applications, though. LC should last a little longer than LS, too.
     
    QT1 likes this.
  8. MonacoMike

    MonacoMike Well-Known Member PLATINUM Sponsor

    Sep 15, 2009
    Indiana lakes and Lake Michigan
    2000 Cruisers 3870
    8.2 Mercs
    85 Sea Ray Monaco 197
    260hp Alpha 1
    What about below the waterline like tabs etc.?

    MM
     
  9. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    IMG_4230.JPG Tiara uses 4200 for port lights and hatches above the water line because it works well and can be removed if you need to make a repair in the future.
     
  10. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    Both LS and LC can be used below the waterline, as well. With the same general +/-'s to each as mentioned above, LC takes longer to fully cure but ends up as a longer lasting fix. I've never looked up the exact specs, but the tenacity of LC reminds me a lot of 4200 but seems to be a little more flexible than 4200 and is not UV sensitive like 4200.

    BUT... note that I'm not saying 4200 is bad. It's just that I've been using the BL products for probably 15 years and have been very happy with them (our shop uses BL products almost exclusively, too). I have used 4200, as well, and have been happy with it.

    But to answer your question... I typically use LC below the waterline - for that added longevity issue, but also because tooling it 'perfectly' isn't as important.
     
  11. MonacoMike

    MonacoMike Well-Known Member PLATINUM Sponsor

    Sep 15, 2009
    Indiana lakes and Lake Michigan
    2000 Cruisers 3870
    8.2 Mercs
    85 Sea Ray Monaco 197
    260hp Alpha 1
    Thanks Dennis, That is what I had them use. On my new boat I had every hole in the boat re-bedded and sealed with LifeCaulk. Only thing not done was shaft seals, they not not leaking, leave them aloe was the advise I got. what do you think?

    MM
     
  12. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    Yeah, I don't see anything wrong with that, Mike. It's not like the seals are going to go from hero to zero over night.
     
    MonacoMike likes this.
  13. Barlow1016

    Barlow1016 Member

    45
    Jun 3, 2017
    Farmington Utah
    1999 340 Sundancer
    454 merCruiser 7.4 MPI Bravo one outdrive’s 4 blade props. 5.0 Westerbeke generator
    I am also replacing all of the snap studs.Do I need to put a dab of life seal on each one of these holes before I screw in the stud?
     
  14. Lazy Daze

    Lazy Daze Well-Known Member TECHNICAL Contributor GOLD Sponsor

    Apr 21, 2009
    PA
    Various
    Various
    The factory did not. But I always do so as it can't hurt. Easier to put a little bit on the threads.
     
  15. domer94

    domer94 Active Member

    202
    May 14, 2017
    norther NJ
    1995 330da
    twin 454 inboard v drives
    hey , for you guys that did your port lights, I think I now have found this is the cause of the water in my stbd aft hanging locker. from the outside you can clearly see the seal has failed between the stainless bezel and the topside. how do you go about doing this job? unscrew the inside bezel / remove and push out the other part? just want to get it straight before digging in
     
  16. my3sons

    my3sons Well-Known Member SILVER Sponsor

    Feb 24, 2009
    NY (Lake Erie)
    2004 400DB, Onan 9 kw Gen, Highfield RIB,
    Cummins 6CTA
    Depends on the port light. Some the ss trim ring has exterior screws, some have plastic components (watch what sealant you use). My boat is as you described, remove interior ring, carefully remove port light from the outside. I have bomar units and the original port lights screw stations broke down over time and half of them were broken and a few more broke when removing them. I bought 2 new portlights. Replaced one on the hard 4 or 5 years ago, replaced one 4 months ago while in the water, working from my dinghy. Both of those had developed cracks in the acrylic lens from age I suspect. They were the fixed type that do not open. Will replace two more when I haul next winter so they are all new. The “new and improved” ones are a much better build than the old ones in my boat’s case. No plastic.
     
  17. domer94

    domer94 Active Member

    202
    May 14, 2017
    norther NJ
    1995 330da
    twin 454 inboard v drives
    thanks , the ones im talking about are the opening type on the cabin side 1995 330da. window / gasket / and dogs are in good shape... so I push it out then slather goop on the inside and press in?
     
  18. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    IMG_4230.JPG
    There are plenty of boats out there with soft decks caused by builders that do not do things according to their own specs. Yes, seal the holes before you install the snaps.
     
  19. sbw1

    sbw1 Well-Known Member

    Oct 10, 2006
    West Michigan
    This is listed in my signature
    This is listed in my signature
    IMG_4230.JPG DSC00070.JPG
    Here is what a port light looks like as it is installed at the factory. If you enlarge the pic you can see the assembly goes thru the hull opening with an outer piece that is finished. On the inside there is a trim subassembly piece that is bonded to the inside of the hull with female openings used for mounting the final trim piece with screws as the interior is finished off.
     
  20. my3sons

    my3sons Well-Known Member SILVER Sponsor

    Feb 24, 2009
    NY (Lake Erie)
    2004 400DB, Onan 9 kw Gen, Highfield RIB,
    Cummins 6CTA
    I don’t want to give you bad info, so go on line and see if yours match up to bomar S516-6-ss, if they do:
    Remove the interior screws and trim ring, carefully remove the unit by prying and cutting the adhesive sealant with a razor. Clean things up with acetone. Check fit of new unit. seal the cutout with epoxy. Let it cure. Place the new unit in the cutout and trace around it with a pencil. Tape off all around that pencil line with painters tape at least a couple inches out. Tape every bit of the exterior of the new port light with tape so you don’t schmuck it up with sealant. Clean up the mating surfaces again with acetone. Put the adhesive sealant on the inside of the stainless portlight ring (The exterior part, not the interior ring) in the sealant channel, enough that you know it will push out and fill all air gaps. Place it in the cutout while your helper puts on the interior ring and snugs down the screws, but not tight, tight enough that the exterior ring is just about touching the fiberglass and everything is even. You push on the port light to get a feel for how much helper needs to tighten the screws. Remove the excess sealant. Tool the sealant with a wet finger. After cure, remove the tape, exacto knife to assist cutting the sealant. Snug down the screws a little more. Rereading this before posting, it’s not as hard as it sounds, my wife and I did this, her inside, me from a dinghy, it’s perfect. have fun.
    7F3AC2EE-044B-4A51-ACEB-4E75DBB9ED78.jpeg

    I added this picture picture that she took from inside the boat to show you that there are no holes in the hull for screws, these are held in by the inner and outer rings being tightened to sandwich in the hull. I recommend adhesive sealant. I want the window attached to the outside of the hull with sealant for when time and vibration loosen the screws. I use 4000UV. 4200 is good too but takes longer to cure. Just my opinion.
    Read everything above about what others use then look at spec sheets, understand silicone, polyurethane and polysulfide based, then you decide.
    570FB180-25E6-453C-876B-302C2DAAB21C.jpeg

    If your’s are not similar to the s516’s then forget all this and you’re on your own.
    Just kidding
     
    Last edited: May 12, 2019

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