Acrylic Port Lights

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captcoho

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Oct 29, 2012
353
Catalina 30 TRBS MkII Milwaukee
Can anyone please offer some advice to removing and re-installing Acrylic Dead Lights ? I have seen a lot of different suggestions as to adhesives and sealants. All of which are very insightful and informative.
Any ideas on how to remove an existing Port Light adhered on to the gel-coat?
I am concerned I may damage the gel-coat or fiberglass being overly aggressive removing the existing crazed and cracked acrylic pane.
Is there a release agent or de-bonding product for the methacrylate adhesive used to install the OEM acrylic pane ?

Thanks in Advance to all replies
 
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captcoho

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Oct 29, 2012
353
Catalina 30 TRBS MkII Milwaukee
Awesome! Will give a shot. I tried scraping the old sealant on the outside and pounded from the inside. I just didn't want to get overly aggressive and do damage.
I thought heating it with a heat gun may expand the acrylic and exacerbate the removal.
 
C

Capt jgw

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Feb 8, 2014
1,300
Columbia 36 Muskegon
You can try automotive brake cleaner, it dissolves just about anything. It might soften the acrylic, but it sounds like you're replacing that anyway. Shouldn't hurt the gelcoat, but do a hidden test spot first to make sure.
 
Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
7,262
Hunter 310 West Vancouver, B.C.
captcoho said:
Any ideas on how to remove an existing Port Light adhered on to the gel-coat?
Click to expand
Before you proceed with the Catalina instructions, I'm going to have to say to go back to the SBO SEARCH menu here. I remember there recently being some excellent posts for installing acrylic. The Catalina instructions are deficient at best and useless at worst for replacing overhead hatch lights and, in fact, would never work for installing (side) port lights.

The old acrylic is best removed with whipping twine or other such string using it as a cutting draw blade between the acrylic and the fiberglass flange. Prying works at narrow contact points but can be difficult at wide contact points.

Uses screws in oversized holes to hold the acrylic in place while it sets, and it does take several weeks to completely set. Once set, the screws are removed and the screw holes filled with DC-795. You've got to be right up against the glass to see where the holes are filled.

One other important item is that the acrylic requires a minimum thickness of DC-795 under it to allow movement in shear. This is achieved with 1/8" thick X 1/4" wide adhesive backed foam tape between the glass and the FG flange. Mount this on the inside edge of the FG flange. Without this, there will be problems with the difference in expansion between the fiberglass cabin and the acrylic.

Lots more useful details which you can pick up in the archives here.
 
FastOlson

FastOlson

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Apr 8, 2010
2,115
Ericson Yachts Olson 34 28400 Portland OR
Checking the archives is a good idea. Using something like a piece of 'piano wire' to cut the remaining old adhesive is a good idea.
I went thru this several years ago and the one trick I learned from a ship wright was to put a little 1/8" black rubber O ring around each hole when doing the final dry fit. This will give you the all-important spacing so that the new lens will have room to expand and contract with temp. changes and not lose adhesion. When you get finally ready to apply that layer of black adhesive (I used "Life Seal", in 1995, and it is still totally water tight on all four large fixed ports), put a toothpick in each screw hole and then drop the O ring on each one. Place the lens in place and squish it down. Insert the screws one by one, pulling out each toothpick in turn.
Another guy did this same project to the much larger lenses on his Ben First 38 and he also has not had any leaks return.
Keep a plastic lined bucket at your side to put the zillions of paper towels in as you work!
:)
Good luck,
Loren
 
D

duality

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May 25, 2004
443
Catalina 400 mkII Harbor
ralph, how could you answer like that, the instructions are exactly the way the factory installs the sidelights per warren pandy of the the largo branch.

i do agree your removing may be neater and safer but i wouldnt skew from the installation recommendation from the factory.


i followed these instructions as described 3 years ago and the installation went effortlessly and looks perfect. no leaks!!!!. the factory sent the foam and sealant.

i would certainly consider the factory recommendations over experts on message boards!
 
Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
7,262
Hunter 310 West Vancouver, B.C.
duality said:
the instructions are exactly the way the factory installs the sidelights per warren pandy of the the largo branch.
Click to expand
If Mr. Pandy says so, I believe him.

However, I fail to see why you would want to follow such a convoluted, contorted, circumlocutious, difficult, and generally round about method :bang: of holding the acrylic to the FG flange while waiting for the 795 to set. Small, temporary screws are so much easier to hold the acrylic in place.

As far as installing a port light (vertical window) I'm at a complete loss to understand how all of these 2 X 4's, lead weights, scraps of carpet, blocks of wood, pieces of flexible wood, and plastic batten like material are going to hold the vertical window in place until the 795 sets. But I guess most anything's possible in this technological age..

duality said:
i would certainly consider the factory recommendations over experts on message boards!
Click to expand
Actually ............. as far as accepting advice from experts on message boards, some pretty smart cookies have posted some pretty ingenious ideas on port/hatchlight replacement here on SBO. I find many of their ideas far superior to what Catalina is offering for installation.
 
Stu Jackson

Stu Jackson

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Feb 26, 2004
23,047
Catalina 34 224 Maple Bay, BC, Canada
Ralph Johnstone said:
Actually ............. as far as accepting advice from experts on message boards, some pretty smart cookies have posted some pretty ingenious ideas on port/hatchlight replacement here on SBO. I find many of their ideas far superior to what Catalina is offering for installation.
Click to expand

+1,000 :theman:
 
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Ralph Johnstone

Ralph Johnstone

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Jan 4, 2006
7,262
Hunter 310 West Vancouver, B.C.
Lambchop27 said:
Also, here's one specifically for Catalinas, Crusing Concepts Window Replacement
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It's unfortunate the amount of rubbish you see on the net and the number of people who may fall for this crap due to a lack of experience.

The instructions in "Cruising Concepts Window Replacement" would result in significant leaks in short order. Nowhere did they mention heavily sanding the acrylic. I searched everything I could on Cruising Concepts for replacing windows but found no mention of sanding. Maybe it's there, but not from what I read.

I have yet to see any instructions which did not include heavy coarse sanding (40-60 grit) of both the FG surface and the acrylic adhesion surface. My personal experience is that 795 will stick very nicely to FG in any surface condition, but acrylic requires a rough surface for long lasting mechanical adhesion.

As far as holding the windows in place while the 795 sets, use temporary screws. The screw was invented centuries ago - use it. I still can't believe the bull about using sand bags hanging over the windows to keep them against the FG.

Check out these poor people who followed Cruising Concepts instructions using tape as a hold down and found the windows releasing after a few days.

http://www.mid-lifecruising.com/2011/10/new-catalina-retrofit-windows.html

At the risk of repeating myself, wading through the instructions and historical experience found here on SBO will produce some of the best recommendations to be found for replacing frameless acrylic windows. And yes, I agree it takes a lot of wading, but it's in there.
 
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