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pfeltham
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Joined: 9/21/12
Posts: 5
1999 Catalina 36 MK II fixed windows

I'm replacing the 4 badly crazed Lewmar opening port light plexi lenses this summer. The 4 fixed Lewmar portlights along the hull are in good shape and don't seem to need any servicing. I'm also considering replacing the 2 long (fixed) plexi windows located on either side of the cabing top. These seem to be adhered to the outer wall of the cabin top with some kind of black adhesive/sealant.

I'm curious to know whether anyone has had any experience doing this on a MKII. It would be great if these could be removed intact so they could be used as a template to cut out their replacements.

In considering this, my questions would be:

1) What is the best way to remove them without damaging them or the surrounding gelcoat...? (I'm sure there's a bit of brute force required here along with other techniques which might include heat... careful prying, etc...)

2) What sealant did Catalina use? Apparantly, it's pretty good. What products are good for cleaning up the old stuff?

3) Has anyone in this forum done this successfully and have they documented the adventure to share it.

Thank you,

Peter F. Ottawa Canada

iamav56
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Joined: 11/25/12
Posts: 54

Hi Peter

Look at the other current thread regarding replacing fixed lights on our boat.

Or do a search for my postings: iamav56.

I make the four fixed long plexiglass lights, available in the color of your choice, just send me the color code. The key here is to buy all four at the same time so you are sure the material came from the same lot.

I just removed the two portside long fixed lights on my 1999 MKII last weekend, I was alone so I didn't take any pics or video but will try to when I remove the other two. Also I will take pics and video during installation.

I also make the opening lights lenses you mentioned in a very beautiful blue, the same color is available for the long fixed lights.

To answer your questions:

1. From the inside my tool of choice is a nice steak knife (smooth blade - no serrations). The blade will need to be about 6 inches long to reach some of the corners. The sealant cuts really easy except where Catalina used their foam blocks so installers wouldn't squeeze all the sealant out of the joint. The blade will not cut into visible gelcoat due to the shape of the recess.

From the outside I usually use a utility knife. The windows are bevelled at a 45 degree angle. I will post pictures very soon... I promise.

2. The sealant you will use to install the replacement is Dow Corning 795 per the factory... I really like it as it has a long work period (it doesn't skin over quickly). You will have a couple of hours working time....more than enough.

3. I have done this job sucessfully (though not perfectly) see the pictures in the link in my other post. The owner of the boat is a friend and I did the installation for free since it was my first. My only real issue is that if you are within a couple of feet of the windows on the exterior you can see that I didn't have enough sealant thickness where a window bridges across a bulkhead so you can see the voids. I did this installation about a year ago, the owner is a friend and happy with the windows and installation but I wish it didn't show those voids.... the darker lens probably hid this for the factory. NO LEAKS. I bought the material today to make 4 new windows for my MKII.

Feel free to contact me if you have more questions about this.

Mark

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HowLin
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Joined: 1/12/12
Posts: 353

Hi Mark - looking forward to your pics/video.
What kind of plexi (and what thickness) did you use for the opening ports?

iamav56
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Joined: 11/25/12
Posts: 54

The pics are posted.

Here is the link:

[url]https://picasaweb.google.com/110180214793263976451/NewWindowsIn87C34[/url]

I am using Chemcast Acrylic Sheet in color 2069.

The factory used 1/4" in the long fixed side lights.
Lewmar (made in England) is using a metric thickness. The closest I can get is 1/4" so I put a stainless steel washer between the "glass" and the hinge and latches to maintain proper pressure on the seals.

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VermontSailor
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Joined: 11/15/08
Posts: 97

A few years ago I replaced the same equivalent fixed windows on a Catalina 30, 1988. Sometime in the mid 90’s I think. Catalina stopped using the screws. The screws on our old Catalina were the source of the initial cracks in the fixed windows. Boat flexes, the adhesive flexes, but the screws against the Plexiglas don’t, causing a stress concentration.

After the adhesive/sealant cured I removed the screws and fill the holes with the sealant and trimmed it flush, for a clean look.

The trick my wife and I used to remove the old windows was to use a wire, such as an “E” string from a guitar with one person on each side running the wire back forth like a saw. The wire broke a number a times, so we switched to dental floss. Dental Floss broke more frequently, but was much cheaper.

iamav56
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Joined: 11/25/12
Posts: 54

I just completed the removal and installation of new fixed windows on my 1999 C36.

I put together a photo essay at the link below. If someone in the know thinks it is worthy, I could probably reformat it into a pdf for a tech article.

[url]https://picasaweb.google.com/106359766496796768233/C36MKIINewFixedWindow...

Comments, questions and/or corrections appreciated.

Thanks,

Mark

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MitchMan406
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Joined: 12/31/11
Posts: 71

Ok, question.
In pic no. 19 of your photo essay, your interior is shown; what color (if any) varnish was used?

I am about to start the stressful and tedious task of re-finishing my complete interior!

Nice job on the pics and overview. We appreciate all the info we can get here.
 

BudStreet
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Joined: 9/4/09
Posts: 1127

Mark, I think it would be a great article for the Tech section, go for it!

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Steve Frost
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Joined: 12/14/07
Posts: 788

The winter 2012 issue of Mainsheet also had two articles covering this subject.

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HowLin
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Joined: 1/12/12
Posts: 353

Thanks Mark - looks great!
BTW, I PM'd you...

pfeltham
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Joined: 9/21/12
Posts: 5

Mark,

A belated thank you for having taken the time to reply to my post and for posting your superb photo essay. I've just gone through the process of replacing all opening port lights and all hatches except for the #65 (trapezoid) hatch. The hatches were very badly crazed except for the 65. I suspect this is because the plexi is quite thick on this one as it is an Ocean version. All of the original #1 Lewmar portlights. leaked from multiple locations. The fixed windows are slightly crazed but not in that bad a shape consideringthey are 13 years old. I will replace these in the spring of 2014. thanks to your essay, I can tackle this with some great techniques and insight.

Cheers and thank you again.

Peter.
Ottawa

pierview
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Joined: 9/27/09
Posts: 502

I have a 2002 and, like everyone else, the ports are crazing. But I'm curious, after all the work some have done to replace the glass panels, what are you doing to prevent it from happening again?

I've spoken to techs at the boat shows about this and from what they say, sunbrella covers on the windows/ports is all you can do. The bottom line seems to be that its a lot of work and expense for something that's going to reoccur. there another way to protect from cracking?

iamav56
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Joined: 11/25/12
Posts: 54

When washing your boat, rinse the windows with fresh water to get as much of the loose contaminants of the windows as possible.

Then wash the plexiglass windows with your boat wash product, it should be mild enough not to hurt the plexiglass. Never use harsh chemicals, acetone, MEK, type producs as they will cause crazing.

When clean, rinse again with clean fresh water.

Dry with a chamois, terry cloth or micro-fibre towel. In the aviation world I come from, many owners/operators will only rub the window in an up and down motion with the towel. The thinking being that any fine scratches that could occur would only cause scratches in the up and down direction and not horizontally too and no circular scratches from rubbing or drying motions in those directions.

There are commercial products for light and heavy scratch removal as well as polishes/waxes that will temporarily fill light scratches.

The Air Force at one time had a program to remove scratches and crazing from cockpit canopies on fighters by sanding out the scratch/crazing with progressively finer sandpapers, compounds and polishes. This might work on the hatches as they appear to be thicker than the 1/4" thick plexi on the long windows on the C34/C36.

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BrentF
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Joined: 1/17/11
Posts: 52

Just replaced the port light lenses from Catalina Direct.  They route the lens out slightly where the outside piece of the latch goes to make up for the metric vs. imperial thickness difference ( I think it is about 1.5-2.0 mm)

The use of alcohol, acetone, or benzoles cause the formation of Craquelée (= mesh-like net of cracks on the surface).  That rules out Windex and most all glass and household cleaners since alcohols are standard cheap ingredient. A number of detergents and cleaners contain benzoles - read label it is sometimes called annulene or phynol hyhride - found in cleaners and waxes  Might also be found in an aerosol spray as part of the propellant.   It also means caution when working acetone cleanup around gelcoat or paint when near the windows.  Sanding with fine grit won't get deep enough to sand out the cracks (in other words don't bother with headlight restoration kits).

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