Boat Life Caulk Vs Butyl Tape for Fixed Ports on Hunter 31

HMT2

.
Mar 20, 2014
900
Hunter 31 828 Shoreacres, TX
We are in the process of replacing the fixed ports on our 1983 Hunter 31. We got the first one out and I have learned a few things I want to share and want to get some guidance. First, on some archived posts about replacing fixed ports on older Hunter 31's there was some indication that you can't just simply replace with a new Lexan piece cut to size. I called Mark with Mark Plastics in Ca. some previous posts recommended him. He asked me if my frame was plastic or aluminum. They are aluminum, he indicated those windows predate his involvement. He did say that he could sell me a new fixed port frame and all that would be plastic and fit. But the aluminum frames are good, plus I would always prefer aluminum over plastic.

Upon getting it completely apart what I found was that the whole thing sets in from the outside. the inside trim is only cosmetic. We can cut a new piece of Lexan bed it in then place the whole frame and glass in from the outside. See Pictures.

So my questions are two.

One. Acrylic vs Lexan? Lexan is more expensive with fewer color options. Acrylic has more color options and UV protection (for the inside).

Two: Bed it into the frame with Boat Life Caulk or Butyl Tape? I would use the Life caulk to bed it in then come back and caulk it in around the frame. For sure I will use Butyl tape when putting the frame in against the boat exterior and screws. The life caulk seems like it would be easier to get into the gap between the glass and the inside of the frame. See the last picture, with existing glass in silicone scraped out, the gap to fill between glass and frame is pretty significant. Your experience would be appreciated.
 

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Feb 6, 1998
11,701
Canadian Sailcraft 36T Casco Bay, ME
We are in the process of replacing the fixed ports on our 1983 Hunter 31. We got the first one out and I have learned a few things I want to share and want to get some guidance. First, on some archived posts about replacing fixed ports on older Hunter 31's there was some indication that you can't just simply replace with a new Lexan piece cut to size. I called Mark with Mark Plastics in Ca. some previous posts recommended him. He asked me if my frame was plastic or aluminum. They are aluminum, he indicated those windows predate his involvement. He did say that he could sell me a new fixed port frame and all that would be plastic and fit. But the aluminum frames are good, plus I would always prefer aluminum over plastic.

Upon getting it completely apart what I found was that the whole thing sets in from the outside. the inside trim is only cosmetic. We can cut a new piece of Lexan bed it in then place the whole frame and glass in from the outside. See Pictures.

So my questions are two.

One. Acrylic vs Lexan? Lexan is more expensive with fewer color options. Acrylic has more color options and UV protection (for the inside).

Two: Bed it into the frame with Boat Life Caulk or Butyl Tape? I would use the Life caulk to bed it in then come back and caulk it in around the frame. For sure I will use Butyl tape when putting the frame in against the boat exterior and screws. The life caulk seems like it would be easier to get into the gap between the glass and the inside of the frame. See the last picture, with existing glass in silicone scraped out, the gap to fill between glass and frame is pretty significant. Your experience would be appreciated.
Port to hull should be Dow 795 (Life Caulk is contraindicated for use with both polycarbonate and cast acrylic.)

You want CAST acrylic such as Cyro Acrylite

The frame to hull and exterior of port can be butyl or more 795..
 

Nils T

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Jun 1, 2014
44
Precision 23 Winter Park, FL
Re: Boat Life Caulk Vs Butyl Tape for Fixed Ports on Hunter

Do a search on Acrylic and Lexan and you will find that Lexan is impact resistant while Acrylic is easy to crack. There are lots of on-line suppliers. I cut a lot of Acrylic in my business and it cracks easily. Lexan will not cost that much more.

One persons opinion.
 
Jun 14, 2011
277
Hunter 22 Fin Keel Lake Martin
Re: Boat Life Caulk Vs Butyl Tape for Fixed Ports on Hunter

Just a note but I replaced the forward hatch window on my 22 with a sheet of lexan this past weekend, Went in easy and looks great.
 
Jun 3, 2004
890
Hunter 34 Toronto, Ontario Canada
Re: Boat Life Caulk Vs Butyl Tape for Fixed Ports on Hunter

I did mine about 5 years ago and they are standing up just fine to our climate- a real test this year and the stress of being hauled out and launched each year. I Cleaned the aluminium frames thoroughly both with silicone remover then sanded them to physically remove any bits and film. I bedded the acrylic t the frames with a strip of butyl then squeezed Dow795 into the frame around the acrylic. I bedded the frame to the fiberglass with 795. There is a detailed description in the modifications section