Forward hatch lens replacement

[Gene Neill]

Has anyone done this job already? My lens is so crazed I'm afraid to look at it hard, let alone step on it. And now, the outside portion of the dogs, the little plastic disc thingys, are falling apart. No way I can put this off any longer.

I have all the necessary stuff (I think) in my cart at CD: lens, gasket, dogs, sealant, and DeBond (for the old sealant). I spent a minute with tech support, just to make sure I had it all right. I guess I'm just hoping for a little more moral support from the gang here, to make me click the "COMPLETE ORDER" button.

 

[SFS]

I did both mine on my Hunter 31, including fabricating my own lenses. I went translucent white, not clear or smoke. If you've got the parts, the job itself is pretty routine.

Before you press go on the order, take a look at the hinges.

Instead of pins to remove, mine had small rolls of very thin aluminum sheet (like a tiny jelly roll). They got pretty mangled being pushed out (even being careful, with a correctly sized punch). If yours is anything like that, consider ordering replacements. I didn't bother, I went with stainless bolts, and through-bolted them, with antisieze. I have aluminum frames.

 

[thinwater]

What sealant?

Mostly it's just cleaning, followed by carefully injecting the sealant. Good masking helps a LOT.

 

[Will Gilmore]

You have my moral support, but if anything goes wrong, I'm not in a position to offer more support than that. You can do it.

Don't mean to be trite, I just wanted to say something so I can follow the job. Post your work for our appreciation, please. I know I'll be impressed.

- Will (Dragonfly)

 

[Gene Neill]

Allrighty then, there's my moral support! Thanks guys! NOW I can get started.

@thinwater , it's Dow Corning 795 sealant. I have applied it before, but never had to remove it. Could be fun. Hope the DeBond is all it's cracked up to be.

@SFS , my hinge pins appear to be solid aluminum. I'll look closer and post pics this evening. I had assumed I would leave the pins in place, and remove the screws which hold the frame to the hinge, but we'll see.

 

[SFS]

I didn't want to rebed anything, AND my boat has a liner, so I don't have access to the underside of the coach roof. So for those reasons alone, my (half) hinges had to stay in place.

I don't remember much about removing the old sealant. For new sealant, I used 795 also, in white. As mentioned above, good masking is important, it will save you lots of time removing squeeze out.

This is also a good time to polish the frames.

 

[ShotgunSlim]

You can do it Gene!! After seeing all your work on the Albin Vega, this should be a piece of cake. I'll continue honking the horn in support as I pass your place on the way to my brothers. I'm due for a week of vacation some time this year.

 

[Gene Neill]

Okay, slight change of plans. I'm going to remove the entire hatch assembly, intact, frame and all. Apparently the frame must have leaked in the past, and a close inspection revealed that some redneck PO had resealed it with ...you guessed it ... clear silicone. So I'll just have to pull the whole ball o' wax at once, and spend half a day of my remaining time on this Earth, removing that garbage from under the frame.

Some pics, starting with the "big picture":

Inside the hinges. Easy to see they've been monkeyed with:

Outside the hinge. The pin looks like a solid rod, not visibly peened, so I don't know what keeps it in place. Hopefully I can leave it alone.

 

[thinwater]

I've done this too many times, and I bet taking it home will actually be faster. Breath deep and put it back on with butyl. I've run into the same thing many times. It's not a problem.

 

[Gene Neill]

I don't expect it to be. Silicone removal is what it is: a tedious PITA, during which it is necessary with every breath to curse the imbecile responsible for your unnecessary drudgery. And not just the imbecile himself, but also the day upon which he was spawned, the womb which bore him, the breast which suckled him, etc, etc. I can get pretty creative with my cursing, given sufficient time.

But in the end, it will be a net positive that the frame is freshly re-sealed.

The parts are on the way, delivery scheduled for Wednesday a week from now!

 

[kbgunn]

Good luck Gene. I'm looking foreward to seeing your results. I've been putting this project off because I see a lot of the same issues on my hatch. I found this video while researching my approach to this project:

I found a few good tips by watching.
- Using the wooden wedges to separate the frame from the deck.
- Naptha to remove adhesive gunk.
- Masking the frame and glass to apply the DC 795
- masking and bead application for re-bedding to get the right amount of "squeeze out" for proper seal.

He uses 3M fast cure 4000 uv instead of butyl. I thought that was smart.
Take it or leave it, it's worth what you pay!

My hatch uses 3/8" smoked plexiglass where as the portlights are 1/4". I haven't been able to find a source with anything above the 1/4" thickness in smoked, so I'll be interested to see if the CD is a drop-in replacement or requires some tweaking.

-KBG

 

[thinwater]

Debond is really for polyurethane--though excellent on 3M5200 and 4200, it doesn't really work on silicone. Re-Move / DSR-5 is what you wanted. You really should subscribe!

https://www.practical-sailor.com/issues/37_73/features/PS-Tests-Adhesive-Removers_12142-1.html

Re-move really helps, just give it time. Slice carefully but deeply through the bond area, let it work for 15 minutes, then give it a go. Repeat several times. I tested a bunch and it is the best for silicone. Debond will work a little if you slice carefully and wait. Unfortunately, they all claim to work on everything, though that doesn't make sense on the face of it; the chemistries of the sealants are too different.

Breath deep. Also, a hose removal hook is handy for the grooves.

 

[SFS]

+1 for the hooked removal tool. Forgot that in my post above.

 

[Gene Neill]

Good news, bad news.

Bad news: The screws which hold the frame together, and those which hold the frame to the hinges, are stuck like Chuck. I've been soaking them in PB Blaster for three days.

Good news: The project can proceed anyway. The lens can be removed from above, simply by slicing the black sealant around it, and gently pulling it loose.

Good news: The sealant which held the lens in the frame was surprisingly easy to remove. A screwdriver, a rag, and Marine Formula DeBond got it done in an hour or two. The frame is thoroughly clean now.

Bad news: I really wish this new lens was about 1/8" bigger all the way around. I have decided it is acceptable, but barely. On a blue water boat, this would not fly.

Bad news: The new gasket is about 1" too short. I can make it work, but will probably contact CD on Monday and ask for a replacement.

Takeaway: My advice to anyone undertaking this project is to remove your old lens FIRST, and examine it closely prior to buying a new one. Better yet, remove your old lens and MAKE a new one. I like CD, and I'm grateful that they are in business. I don't wish to disparage them. But acrylic is cheap and easy to work with. And for less money, I could have easily fashioned a better-fitting lens. And before ordering the gasket, I would take careful measurement and request the material be of the appropriate length plus two inches.

Upward and onward. The Big Lie says 100% chance of T storms all day tomorrow, so no more progress likely soon.

Pics of old lens, showing the crazing:

 

[Aplusryan]

Gene,
I really enjoy your YouTube videos first off. I replaced my lense with one from CD last month. Mine was “held” in place with clear silicone. Man I’d like to kick the dude that did that in the b@!!5. My reason for replying is to warn you about possible core rot behind the frame. I have to wait for temperatures above 60 degrees in northwest Ohio before I can break out the epoxy to fix it. The 795 has a recommended cure time of 3 weeks also. Make sure to get a little sealant on top of the gasket flange too.
I liked your insight on the bulkhead replacement. I got my teak caps off intact with a soaking in xylene and a heat gun. Off to buy some form of teak or mahogany plywood tomorrow. My 22 is a New Design also. A 1989 wing keel to be more specific.

 

[Gene Neill]

Thanks @Aplusryan . The lens replacement job is done ... I think.

I spent forever prepping and masking everything perfectly, thought everything through, had everything I might need within arms reach before I cut the tip off the 795. Then did a spectacularly flawless caulking job. I mean perfect, better than new.

Then, as I was joyfully and triumphantly pulling off the masking tape ... the lens shifted!! !!!

I hadn't thought about THAT. There was nothing holding the lens in place but gravity, and it lifted up a bit, spoiling my immaculate caulking job. I nudged the seal back around a bit - cursing bitterly and weeping tears of rage and frustration - and got it centered in the frame again. Left it to cure. I don't think it will leak, and no one but me will ever notice the imperfect caulk, but I'm still bummed about it. It was SO perfect. Now it's not, and will never be, unless I start from ground zero all over again.

All that whining aside, I have not gotten the necessary screws loose to remove the frame from the deck and re-bed it. I haven't tried in a couple days, since the caulk incident. I hadn't considered the possibility of any core rot, since the boat is rock solid everywhere else. I'll just have to keep up with the PB Blaster, and keep my fingers crossed.