Removing old window sealant.

[Michael-Louis]

Hi All,
I have a leaking window on my 35.5 legend 1992. Anybody can tell me how to start with removing the old sealant around without scraching the gelcoat?

 

[Knotallthere]

I did this project 2 years ago on my Hunter 356 for the two skylights / windshield forward of the mast. I carefully removed the old caulking with an exacto blade. Once the old caulk was removed from the joint I used acetone to remove any residue. I then used Dow Corning 795 black laying down a bead using painter's tape (put it on like somebody else is paying for it) once the beat had been laid in the joint I then used a smoothing tool from Home Depot for caulking to go around and make everything look nice. Turned out to look better than what the factory did. I didn't have to completely remove the acrylic and haven't had a leak since. Good luck!

 

[thinwater]

Re-Mov is the thing for silicone sealant, which I'm guessing is what you have (probably Dow 295, as stated above). Score deeply along the bond line, apply, and let is work for 10 minutes. Repeat. The advantage is that it is much easier to remove the residue and new silicone will bond better.
https://www.practical-sailor.com/issues/37_73/features/PS-Tests-Adhesive-Removers_12142-1.html

 

[JimInPB]

I always start with a razor blade first & get 90+% of it out with that. Sometimes I can then use a rubber palmed glove to rub off the thin film that remains.

795 seems to be the generally accepted "proper" product for mounting the new windows. Be aware that there are specifications for bead height & thickness to allow for a little give so that you don't have issues when the window & the hull expand at different rates due to temperature change.

 

[AlastairLC]

If there’s a lot of sealant between the plexiglass and the gelcoat, use cutting wire.

 

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[Michael-Louis]

I did this project 2 years ago on my Hunter 356 for the two skylights / windshield forward of the mast. I carefully removed the old caulking with an exacto blade. Once the old caulk was removed from the joint I used acetone to remove any residue. I then used Dow Corning 795 black laying down a bead using painter's tape (put it on like somebody else is paying for it) once the beat had been laid in the joint I then used a smoothing tool from Home Depot for caulking to go around and make everything look nice. Turned out to look better than what the factory did. I didn't have to completely remove the acrylic and haven't had a leak since. Good luck!

If you look at the picture you should see that it is not a alu-framed window but sealed directly to the gelcoat. Therefore you have to be more careful when removing the old sealant. Anybody did it on a "non alu-framed" window and can tell how?

 

[nfg2u]

Michael, I have a 35.5, I used a heave plastic putty knife followed by acetone and then sanded what remained. I wanted a rough surface for the sealant to grab onto anyway. I used Dow 795 to reseal. No leaks in 18 months. Did my side windows as well. I found spider cracks in the corners which I Dremeled, then filled with Marine-tex. I would re-gelcoat now, but at the time I had not done any gelcoat work. PM me if you wish for more info.

 

[Michael-Louis]

Thanks a lot guys! Now all I have to do to start the bloody job. Although we are far away from the tropicals we have rain every day. After the rain stops for a whyle I get into it and let you know. Thanks again.

 

[Tom23254]

I have had 1992 42 hunter for 12 years. When i got it , the big front window and one side window leaked. I started with razor blades. But found it way to easy to slice into the gelcoat. So i moved onto a red devil paint scrapper. And hammered it in. That worked. But was a lot of work.
Last year I replaced all 4 side windows and I used a Multi-purpose Oscillating tool. With a paint scraper on it. I cut all the windows out in 1/50th the time. And than used it to remove most of the old sealant. You can get this tool at Home depot for 30 bucks or harbour freight for 25. It will save you a lot of time and when you have another window you can use it again.
I Did use Acetone for final cleaning b4 using Dow 795 to put all new windows in.

 

[Michael-Louis]

Thanks a lot Tom!

 

[Scott B]

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