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1 - 9 of 9
[Amel Yacht Owners] Goit Deck Hatch Lens Reseal
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Eric Freedman
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I’m just about to do one on Kristy, Bill. It had cracked last year and I had it done professionally by a company in Ft Lauderdale. They used a clear silicone caulk which leaked a couple months later. From what I’ve been reading, a glazing sealant by Dow (DC795) is what many professionals use, and what I’m going to use. My hatch lenses are plexiglass, not acrylic. I don’t know if DC795 works on acrylic or not. For what it’s worth, there’s another product called DeBond that was designed to release 3M’s 5200 sealant. I used it to get the hatch frame off of the deck and it made that job, and cleaning the old sealant off of the frame MUCH easier. Kent S/V Kristy SM 243 There is a specific silicone for bonding acrylic to aluminum. I forgot which one it was. Last time I called GE silicone division and they gave me the number it is not your regular silicone. Also when I rebuilt my last boat I spoke to the people at Atkins Hoyle. They recommend to prime the edge of the Plexiglas and the frame with toluene . It made the surfaces very sticky and the hatches never leaked. I also used under the genoa cars and the silicone stuck like crazy to it. Be careful as it is very toxic. Fair Winds, Eric SM 376
On Tue, Sep 25, 2018 at 12:02 PM, greatketch@... [amelyachtowners] wrote:
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svsunnyside
Hi Kent Acrilic and Plexiglas are the same. Plexiglas is the trade name given by the inventor Roehm & Haas . Regards Gabriele Sunny Side Maramu #219
On Wednesday, 26 September 2018, 12:33:06 GMT-4, Kent Robertson karkauai@... [amelyachtowners] wrote:
I’m just about to do one on Kristy, Bill. It had cracked last year and I had it done professionally by a company in Ft Lauderdale. They used a clear silicone caulk which leaked a couple months later.
From what I’ve been reading, a glazing sealant by Dow (DC795) is what many professionals use, and what I’m going to use. My hatch lenses are plexiglass, not acrylic. I don’t know if DC795 works on acrylic or not. For what it’s worth, there’s another product called DeBond that was designed to release 3M’s 5200 sealant. I used it to get the hatch frame off of the deck and it made that job, and cleaning the old sealant off of the frame MUCH easier. Kent S/V Kristy SM 243 There is a specific silicone for bonding acrylic to aluminum. I forgot which one it was. Last time I called GE silicone division and they gave me the number it is not your regular silicone. Also when I rebuilt my last boat I spoke to the people at Atkins Hoyle. They recommend to prime the edge of the Plexiglas and the frame with toluene . It made the surfaces very sticky and the hatches never leaked. I also used under the genoa cars and the silicone stuck like crazy to it.. Be careful as it is very toxic. Fair Winds, Eric SM 376
On Tue, Sep 25, 2018 at 12:02 PM, greatketch@... [amelyachtowners] wrote:
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Hmm, thanks, Gabriele, I didn't realize that. When I ordered the new lens, I was told I could either have acrylic or plexiglass. Acrylic being stronger, but Plexiglass being more resistant to scratches. Here's a blurb I just found: Although Plexiglass is a form of acrylic plastic, there
are subtle differences between the two types. Plexiglass has the
distinction of being harder than normal acrylic which makes it easier to
drill and cut without breakage. Additionally, Plexiglass is more
chemical resistant than traditional acrylic. I looked it up on Dow's info page. Scuffing the acrylic with 80 grit sandpaper, then cleaning with alcohol is recommended with DowCorning's 795. I'll let everyone know how it turns out. I'm using DC795 grey color. Kent SM 243 Kristy
From: "Gabriele Antolini svsunnyside@... [amelyachtowners]" To: "Kent Robertson karkauai@... [amelyachtowners]" Sent: Thursday, September 27, 2018 11:32 AM Subject: Re: [Amel Yacht Owners] Goit Deck Hatch Lens Reseal Hi Kent Acrilic and Plexiglas are the same. Plexiglas is the trade name given by the inventor Roehm & Haas .. Regards Gabriele Sunny Side Maramu #219
On Wednesday, 26 September 2018, 12:33:06 GMT-4, Kent Robertson karkauai@... [amelyachtowners] wrote:
I’m just about to do one on Kristy, Bill. It had cracked last year and I had it done professionally by a company in Ft Lauderdale. They used a clear silicone caulk which leaked a couple months later.
From what I’ve been reading, a glazing sealant by Dow (DC795) is what many professionals use, and what I’m going to use. My hatch lenses are plexiglass, not acrylic. I don’t know if DC795 works on acrylic or not. For what it’s worth, there’s another product called DeBond that was designed to release 3M’s 5200 sealant. I used it to get the hatch frame off of the deck and it made that job, and cleaning the old sealant off of the frame MUCH easier. Kent S/V Kristy SM 243 There is a specific silicone for bonding acrylic to aluminum. I forgot which one it was. Last time I called GE silicone division and they gave me the number it is not your regular silicone. Also when I rebuilt my last boat I spoke to the people at Atkins Hoyle. They recommend to prime the edge of the Plexiglas and the frame with toluene . It made the surfaces very sticky and the hatches never leaked. I also used under the genoa cars and the silicone stuck like crazy to it... Be careful as it is very toxic. Fair Winds, Eric SM 376
On Tue, Sep 25, 2018 at 12:02 PM, greatketch@... [amelyachtowners] wrote:
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I think maybe you're referring to Plexiglas rather than plexiglass .......
Cheers Alan Elyse SM437 Bonne Anse
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Very informative, Alan, thanks. So unless I was led astray, I must have Plexiglas. Either way, the DC795 should work if I rough the lens up a bit.
You guys never cease to amaze me. Kent S/V Kristy SM243 I think maybe you're referring to Plexiglas rather than plexiglass ....... Cheers Alan Elyse SM437 Bonne Anse
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Eric Freedman
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Ryan Meador
When I redid the hatches on my old boat, Atkins and Hoyle recommended GE SCS2000 silicone. It worked great and was still strong and leak-free when I sold the boat 7 years later. Also at the recommendation of A&H, I used Silaprene (though I'm not sure which specific variant) for attaching new hatch gaskets at the same time and it held up great. Ryan and Kelly
SM 233 Iteration Boston, MA, USA
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greatketch@...
Ryan,
I ended up using SCS200. I had some onboard, it was suitable for the purpose. There are a number of silicones formulations that will stick to both acrylic and aluminum, but in every case the surface prep is critical, especially for aluminum. As we disassembled and cleaned out hatch frame, the failure was obviously at the silicone/Al bond because there was a lot of debris of older sealant remaining behind. The surface prep for the last repair was just not good enough. Once ALL of the old sealant has been removed, and the surface solvent wiped, the aluminum should be wire brushed to remove all oxidation and old sealant. Then wipe it again to be sure the surface is clean of dust. Cover with silicone sealant right away, before oxidation can significantly change the surface of the metal. The surface of the lens should be throughly cleaned, and then wiped with isopropyl alcohol, then do not touch the sealing surface with bare fingers. Skin oil can reduce adhesion on the smooth plastic surface. I avoid using solvents that can attack acrylic like toluene, MEK, and acetone. The risk of damage to the unsealed part of the lens is too high. There wasn't anything unusual about the Goiot hatches. Things went very much as I expected. Hopefully, nothing to worry about there for years.... Bill Kinney SM160, Harmonie St. Michaels, MD, USA
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