looking for input on gelcoat application on M-17
To add gelcoat or not? Here's the deal; we stripped all the paint below the water line since we didn't know what it was, and it needed refreshing. I also removed a through hull, and redid a couple old through hull patches I found because I didn't like the looks of them. As we removed paint we found many areas (particularly under the lapstrake edges) where the gelcoat had been previously been sanded through. And of course I have the new repairs I did. Should all this have gelcoat reapplied over the fiberglass? I will be using Interlux 2000e primer, and maybe Bottomkote NT over it (not sure on that yet). The boat will be moored in fresh water for 5-6 months. Any thoughts on what should be done for proper protection/longevity of hull?
Gerry, a coat of clear ex poly or gel coat will keep the water from working it's way into the fiberglass, make sure you wipe the area with acetone. have fun only. On Thu, Apr 25, 2019 at 5:11 AM Gerry Lempicki via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
To add gelcoat or not? Here's the deal; we stripped all the paint below the water line since we didn't know what it was, and it needed refreshing. I also removed a through hull, and redid a couple old through hull patches I found because I didn't like the looks of them. As we removed paint we found many areas (particularly under the lapstrake edges) where the gelcoat had been previously been sanded through. And of course I have the new repairs I did. Should all this have gelcoat reapplied over the fiberglass? I will be using Interlux 2000e primer, and maybe Bottomkote NT over it (not sure on that yet). The boat will be moored in fresh water for 5-6 months. Any thoughts on what should be done for proper protection/longevity of hull?
gel coat will keep the water from working it's way into the fiberglass,
A polyester gelcoat will provide no additional protection from blistering than the polyester resin used to lay up the hull. An epoxy barrier coat does provide some protection.
coat of clear ex poly [epoxy]
This is better than polyester but would make application of the bottom paint harder. Epoxy dries hard and slick. The amount if sanding required would be extensive including removal of the blush (depending on epoxy used). Barrier coats like Interlux 2000e or Pettit Protect have additives making them work better than 'just epoxy' and have an application window where no sanding required between coats and applying the antifouling. :: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/ On Thu, Apr 25, 2019, 6:52 AM carlos navarro <chisailor1@gmail.com> wrote:
Gerry, a coat of clear ex poly or gel coat will keep the water from working it's way into the fiberglass, make sure you wipe the area with acetone. have fun only.
On Thu, Apr 25, 2019 at 5:11 AM Gerry Lempicki via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
To add gelcoat or not? Here's the deal; we stripped all the paint below the water line since we didn't know what it was, and it needed refreshing. I also removed a through hull, and redid a couple old through hull patches I found because I didn't like the looks of them. As we removed paint we found many areas (particularly under the lapstrake edges) where the gelcoat had been previously been sanded through. And of course I have the new repairs I did. Should all this have gelcoat reapplied over the fiberglass? I will be using Interlux 2000e primer, and maybe Bottomkote NT over it (not sure on that yet). The boat will be moored in fresh water for 5-6 months. Any thoughts on what should be done for proper protection/longevity of hull?
From what I hear and know from the boatyards here, they would likely not do a gelcoat re-coat, but do an epoxy barrier coat. I've been very happy with the two-part epoxy finish, spraying it. And the new poly finishes are rock hard and roll on nice. As you ask, "should all this have gelcoat reapplied"-- that is quite a job as far as getting a smooth finish. There is a difference between a work boat and a pleasure boat that might be raced... or a boat to be sold in the future. My friends with lobsterboats will do a gelcoat "recoat" where they have done repairs topside with roller and brush as they don't care if it is rough. But trying to get gelcoat smooth is a heck of a job and the newer coatings like the two part epoxies smooth out much better. In my experience of spraying, rolling, and brushing on gelcoat for boat repairs, you are looking at a nightmare to try to get a smooth job. One must have the exact amount of catalyst according to temperature, keep it chilled, and then it seems no amount of care can get it smooth or the right thickness everywhere. Attempts to brush it out, smooth it out, etc. only make it worse. And if you get too much catalyst it will smoking hot in the container on a summer day especially and will kick all at once... One friend here who used to do 'glass in a boatyard, even so didn't get enough catalyst in the gelcoat and had his entire bulkhead sticky for a year or so on a Bristol 19. (He's not too fastidious, didn't seem to bother him much.) I can't imagine trying to do this UNDER a boat, it is hard enough on vertical and flat surfaces, let alone lapstrake. I've always had to sand out the brush marks, then go finer and finer until power polishing-- your mileage may vary.
Burt Monty 12 On Thu, Apr 25, 2019 at 9:11 AM Gerry Lempicki via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
To add gelcoat or not? Here's the deal; we stripped all the paint below the water line since we didn't know what it was, and it needed refreshing. I also removed a through hull, and redid a couple old through hull patches I found because I didn't like the looks of them. As we removed paint we found many areas (particularly under the lapstrake edges) where the gelcoat had been previously been sanded through. And of course I have the new repairs I did. Should all this have gelcoat reapplied over the fiberglass? I will be using Interlux 2000e primer, and maybe Bottomkote NT over it (not sure on that yet). The boat will be moored in fresh water for 5-6 months. Any thoughts on what should be done for proper protection/longevity of hull?
No need to apply gel coat Gerry. Prep according to 2000e's the bare fiberglass sanding and cleaning instructions. Once you have the barrier coat on they apply antifouling that has good reports for the area. Be sure to use a antifoul paint that has an unlimited dry time before launch (such as Pettit Hydrocoat, Pettit ViViD, Sea Hawk Cukote and as you noted Bottomkote). :: Dave Scobie :: M6'8" #650 :: SV SWALLOW - sv-swallow.com :: former owner M17 #375 SWEET PEA - m17-375.com :: former owner M15 #288 SCRED - www.freewebs.com/m15-named-scred/ On Thu, Apr 25, 2019, 6:11 AM Gerry Lempicki via montgomery_boats < montgomery_boats@mailman.xmission.com> wrote:
To add gelcoat or not? Here's the deal; we stripped all the paint below the water line since we didn't know what it was, and it needed refreshing. I also removed a through hull, and redid a couple old through hull patches I found because I didn't like the looks of them. As we removed paint we found many areas (particularly under the lapstrake edges) where the gelcoat had been previously been sanded through. And of course I have the new repairs I did. Should all this have gelcoat reapplied over the fiberglass? I will be using Interlux 2000e primer, and maybe Bottomkote NT over it (not sure on that yet). The boat will be moored in fresh water for 5-6 months. Any thoughts on what should be done for proper protection/longevity of hull?
participants (4)
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Burton Lowry -
carlos navarro -
Dave Scobie -
Gerry Lempicki