[C320-list] Hatches and Portlights and Deadlights...oh my...

[Troy Dunn]

The threads on the original poster's question about deadlights (the fixed,
non-opening 'windows' in the galley, head, salon, etc.) vs. non opening
portlights vs. opening portlights (typically Lewmar) vs. hatches (typically
Bomar on older hulls and Lewmar on newer) was getting difficult to follow
and lots of the information in there could be misleading depending on which
item you are trying to fix and what year your boat is.

For all of these items, please be aware that the preferred material of boat
builders is cast acrylic, not polycarbonate (aka Lexan) and not extruded
acrylic. Polycarbonate while intially stronger is an inferior material
for applications in sunlight due to UV degradation. Cast acrylic is the
best product and it machines readily and quite nicely.

I am currently in the process of replacing my forward trapezoidal hatch
with a new cast acrylic lens. I bought the material from estreet
plastics and will use the old lens as a template for the new one. I will
post up some pictures on the process when I'm done. I already replaced
the salon and head lenses using lenses bought from Catalina direct. The
Catalina direct price is steep for what you are getting, so I figured I
would attempt to build one myself and see how this goes. For price
comparison know that you could obtain enough acrylic for all three hatches
for about $100 out the door inclusive of shipping. This of course assumes
you have a router table or CNC machine available for your use.

On the topic of dead light replacement, I have seen videos and diagrams of
a frame that holds weight and pushes against the deadlight with legs braces
against the bulwark (aka toe rail). This is the old school approach that
uses normal marine sealants. I would be curious to hear if anyone has
gone the VHB double sided tape route. That could potentially eliminate
all the fussing with weights etc. alternatively if one didn’t trust the
UHB, you could run a thin inside gasket of UHB tape for holding power and a
plain sealant on the outer edge. I know how crazy it sounds to 'just tape
your windows in place'. But honestly I have used Sailrite's 3M SNADs which
also use VHB tape and the holding power is pretty amazing.

For normal portlights there are already tons of good articles here already
so I won’t dive back into that pond.

Troy Dunn
Hull #514

[Michael Ferguson]

Troy. We have a plastics fabricator in town J.W. Austin. He had made new portlights and hatches for me at 1/2 cost of Direct. Perhaps you have one near you. MichaelHull 169

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On Fri, Nov 20, 2020 at 6:13 PM, Troy Dunn<troutw...@gmail.com> wrote: The threads on the original poster's question about deadlights (the fixed,

[Dave Hupe]

Troy - with the experience I had when I replaced my 1994 boat's "deadlights" (the 4 fixed, non-opening 'windows' in the galley, head, salon, etc.) in 2017, I do not recommend planning on relying on the VHB tape.  It sounds like a good idea, but the new cast acrylic lenses I bought directly from Catalina Yachts did not fit the cavities uniformly (even though I provided exact tracings for each window). You need a good seal all around the new acrylic. Some of the new lenses were very tight in the mount cavities.  Therefore, the seal was mostly between the hull cavity and under the beveled inside edge of the lens, rather than around the lens perimeter,  Then, I had some lenses that were loose/smaller than I would have desired.  In this case, there wound up being a very good/wide seal around the lens perimeter as well as under the lens. 
If you relied on UHB tape and the lens was tight in the opening, you might end up with inadequate sealant.
As I mentioned in my answer to the other recent post inquiring about " replacing portlights", I had an article published in the Spring 2018 Mainsheet (page 28) with a procedure and photos for when I replaced my deadlights (this is what Jeff Brown was asking about when he listed "portlights" as the prior topic ...... I agree the terminology can get confusing). I will be happy to email my original draft procedure with many more photos than were allowed for the magazine if anyone is interested.  Just email me directly at hoop...@yahoo.com.
Dave Hupe
1994 C320 (#32) 
Holland, MI

[Bruce Heyman]

Thanks Dave,
Sounds like the deadlight replacements that you got from CD not exactly match the tracings that you provided. Sounds like we might be better off having the produced locally where they can use the existing ones as a pattern?
Thanks,
Bruce
Somerset, San Pedro

[Dave Hupe]

I was told by Catalina Yachts that they had templates for the windows ("deadlights").  However, they said they still wanted tracings to check against their templates. Believe me, my tracings were very exact.  I think someone at Catalina compared them (hopefully), but determined that they were close enough to just go from their templates. As I said they didn't fit as would have liked, but I made it work. 
Catalina makes a special bevel on the edge of these windows for mounting. So, I doubt you would be able get a local manufacturer to replicate that.   
Dave Hupe
1994 C320 (#32)________________________________________________________________________________________________________

[Jeff Hare]

Hi Troy,

By deadlights, I assume you mean the two long smoked windows in the galley / head? If you mean the aft cabin porthole and the main cabin portholes, these probably clamp in place once the inner trim ring is removed. But I suspect you mean the former...

We use VHB quite a bit installing keder welt track. It's great stuff. The problem you'll likely face is that while VHB is great for holding materials together, most long-term applications involve bonding two non-transparent materials which protect the adhesive and (typically) foam structural core of the tape. In this case, since you're bonding a semi-transparent surface to fiberglass, there is likely to be long-term UV exposure on the glass side of the adhesive (what little UV makes it through the smoked Acrylic). I think this is a case where VHB might have met its match. But the tech department at 3M has answered questions for me in the past and may help you here. I suspect that you'd really need to use polysulfide or whatever the factory recommends.

Cheers!
-Jeff Hare

PS: when I mill acrylic or polycarb, I typically cut slightly oversized parts using hand held router with a deep V bit and a ~1/4" oversized collar that and use many passes scoring deeper until I have a blank that's slightly larger than finished size. Then I use a durable spiral down-cut bit to bring it to finished size. Whenever I've tried to just mill that in one pass I get chipping and micro-cracks. Just my preference though... 😊

[John Morrison]

I ordered my dead light lenses from Catalina in FL. I visited the plant in Seminole and saw where they were produced. I have yet to install them but my neighbour did following the process on the 320 website. He used the Dow Corning 795 product. I used the DC caulk to replace the lens on the center cabin hatch. Easy pesy if you plan it out.
JohnM
1999#574

Sent from my iPhone

> On Nov 21, 2020, at 9:26 AM, Jeff Hare <Cata...@thehares.com> wrote:
>
> ehalf Of Troy Dunn

[Troy Dunn]

All-

Thanks for the responses. For some reason this whole thread went into the
spam folder? It seems like google changed its algorithms and a lot more of
the forum posts end up in spam now. Sigh.

I think I'll stay away from VHB for deadlights. Hadn't thought about the
beveling of the edges and possible UV issues. A lot to think about there.

Jeff-

I ended up using a larger bosch 3/4" bit with significant anti-kickback
shoulders. I also used a router table setup as opposed to hand held.
When I saw your note I had an "oh crap" moment and went and unwrapped the
new lens. All is well; "phew". One cautionary note. The acrylic
becomes electro statically charged. I literally got flocked while doing
this project as did half my workshop. I have pictures up in the gallery
of the cutting phase of this project. Waiting for the gasket and Dow 795
to arrive.

Cheers-

Troy

On Sat, Nov 21, 2020 at 9:45 AM John Morrison <sail-a...@sympatico.ca>
wrote:

[Jeff Hare]

LOL! Static! I just finished milling down a whole set of cushion seat bases out of cellular PVC to replace some rotted wooden ones and while vacuuming up all the PVC router 'snow' I got my bald head a little too close to the table saw. The static buildup saw an opportunity to send a storm sized lightning bolt off my head.

I think I'm still smelling smoke. After a day or so, Shelly has finally stopped laughing at me, so that's good anyway, right?

-Jeff

-----Original Message-----
From: C320-list <c320-lis...@lists.catalina320.com> On Behalf Of Troy Dunn

[Chris Burti]

😂

Best Regards,
Chris Burti
Commitment #867

> On Nov 24, 2020, at 10:32 AM, Jeff Hare <cata...@thehares.com> wrote:
>
> LOL! Static! I just finished milling down a whole set of cushion seat bases out of cellular PVC to replace some rotted wooden ones and while vacuuming up all the PVC router 'snow' I got my bald head a little too close to the table saw. The static buildup saw an opportunity to send a storm sized lightning bolt off my head.

[Troy Dunn]

Oh wow! I have read articles in wood working magazines about being careful
with plastic hoses on the dust collector but that was always about igniting
wood dust. There is no mention of building up St. Elmo's sized charges on
the cabinet saw and sending a jolt to the unsuspecting woodworker. That
had to be quite a shock! 🌩

Troy