Hunter 28 Owner Modifications and Upgrades

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Replacing Gray Ports portlights

posted 10-07-2008 by Terry Arnold | Add this mod to a FAQ

The opening Gray ports are showing their age. On my 79 H33, the lip extending past the
outside trim ring had broken on several and a previous owner, probably after cutting an
ankle on the jagged edges, had cut them off more or less flush with the trim ring. He used
a chain saw judging by the neatness of the operation Thus, replacement was a foregone
conclusion, the only question being what port to use for replacement.
Stainless or bronze seem an attractive possibility but several on the Hunter site who have
installed the Newfound Metals port mentioned shortcomings, e.g. “the adjustments for
both the locks that you do manually and the adjustments at the top to adjust at the hinge
will not stay set.......They must be screwed down very tight to hold water out.........the
bronze tarnished badly and quickly” and “They require a hook and chain to keep open.
The spigot is not angled so they cannot drain. With the slope of the cabin sides there will
be 1/2” “ of water lying against the glass after a rain or wave.” Also, the bronze or
stainless ports are several times the price of the gray ports.
Since I had 11 opening ports to replace and since, after all, I have a 22 year old plastic
boat with the original plastic ports that didn’t leak even when I replaced them, I opted to
go with the replacement plastic Gray ports. When they arrived from Thrifty Mariner slight
changes in the new ports show several improvements over the originals:
1. The two drains are molded integrally into the port. The original ports had a clear
plastic drain tube stuck into the molded part with the free end being supported only by
caulking before exiting through a hole in the outside trim plate, resulting in a fragile
appendage that could leak at the junction or along the length of the tube. Where the end of
the tube saw light, it had crystallized from UV. In at least one instance of moisture in the
core that I noted when I removed the ports, the source seems to have been a broken drain
tube. Since the old ports dump right into the core if they leak, the new molded drain is a
large improvement.
2. The outside trim rings have no screw holes. The original trim rings were fastened to
the cabin trunk with a lot of screws, with a lot of holes in the cabin trunk and more chance
of water entry. Since the outside and inside flanges are not bolted together, removing the
screws serves to emphasize the real function of the outside trim ring, sealing pure and
simple. Thus, the clean trim ring should seal better and does look better without the
essentially non functional outside trim screws.
3. The 7x14 ports have a third hinge at the top, right in the middle which serves to stiffen
the lens, making sealing better, and increasing strength.

Old Gray Portlight

The original caulking is a kind of silicone? Looks and acts like silicone anyway. It has
tremendous adhesion and thus sealing ability and a relatively weak shear strength. When
the old caulk came out, it was still very elastic, showing no apparent aging in 22 years.
This weakness of the caulk is good for removal since it lets the ports come out fairly easily. Two tools that proved very useful in the removal are shown here. The 8” trim pry
bar proved just right in easily getting behind the trim ring, cutting the caulk and prying off
the ring. ( I got this tool from They list it as a restorer’s cat’s paw.) After
the ring was removed, a very sharp 3” putty knife proved just the tool to cut through the
caulk all the way through the trunk to the inside flange. Working the knife all the way
around the port in overlapping steps, each time cutting through to the inside flange cuts
through the sealing caulk, leaving only the inside flange screws holding in the port. With
their removal, the port should come out easily.

Port Removal Tool 1

Port Removal Tool 2

. Condition speaks well for the original installation quality. In removing the ports I was
struck with the quality of the original installation, particularly the practically complete
filling of the gap between the port and the cutout with the caulk. . This closeup also
shows clearly the general cabin construction cross section. cabin top-deck and the liner
were evidently laid up separately, then nested and bonded together. With such a large
bonding surface and irregularities in lay-up, voids between the two sections inevitably
occurred. At each port cutout hidden by the inner flanges I found a number of irregularly
spaced countersunk screws whose evident original purpose was to bridge the gap
appearing when the builder cut the original hole in the cabin trunk, drawing the assemblies
closer together and the inner liner into a plane surface for the attachment of the inner
flange of the port. With this type of construction, the inner surface and outer surface of
the cabin trunk are not necessarily parallel, making replacement port installation requiring
through bolting more difficult. Since the original equipment ports were structurally
attached only from the inside, this lack of being parallel posed no major problem for this
design and is another reason to replace with the original equipment type of port not
requiring through bolting.. The inside flange screw spacing is also identical except at the
new center hinge location so the original screws can be reused.

Closup of typical cabin trunk section

A sharp 1” wood chisel is a good scraping tool to remove all of the old caulk from the

Cleaning cutout of port

To locate the cutouts necessary for the relocated drains in the new ports, place the new
port in the old hole and center fore and aft by sliding it back and forth to estimate the
center. At the estimated center, mark the centerline of the new cutout as shown in the

Locating New Drain Cutout

I made the lower part of the cutout for the new drains with a 7/8” spade bit, being careful
not to cut below the lower edge of the flange which is pretty clearly marked on the cabin
inner liner. also, the old drain hole cutout serves as a useful gage to judge the angle for the hole. After boring the hole, I used a saber saw to cut the sides of the hole up at the
hole diameter dimension. All of this makes a huge mess inside the cabin. Cushions should
removed before starting all of this.
The original drainage cutout is filled with thickened epoxy. Also use the thickened epoxy
to fill all of the old screw holes, inside and out. I made no attempt to epoxy the whole
section solid. Rather, I tried to follow the clearly successful strategy of the original
installation which was to caulk the annular space solid between the frame of the port and
the cutout and then really concentrate on sealing the outside flange. Evidence of water in
the plywood core that showed when the ports were removed, seemed to come only from
migration down from a leaking forward hatch and from handrail screw holes. Evidence of
water in the core had showed up even before removal with a brown stain below the inside

Cutting the New Drain Cutout Hole

With all of the portlights out I took advantage of the great opportunity to go ahead and
paint the trunk of the cabin with two part polyurethane Interthane plus. The messy edge
will be cleaned up when the non skid is painted later

Hole Ready for New Port Installation

The label attached to the new ports is reproduced. It calls for silicone caulk only.
I used GE Silicone II for bath since it includes an anti-mildew agent and is touted by the
label as having high adhesion to just about anything. My experience with this caulk confirms this. This caulk is not very strong in shear
strength and thus seems to match fairly well the characteristics of the original material. As
will be seen in the photos following, filling the space between the port and cutout is
difficult and it is really important that the caulk used guns well. Silicone guns very well
indeed. The Silicone II caulk also cleans up fairly easily.

New Portlight caulk Specification

To start the installation, mount the port temporarily with a couple or three screws to make
sure that the new drain cutout will fit properly and to observe the gap between port and
cutout from the outside.

Installing temporarily to observe spacing

After removing the temporarily installed port, gun the caulk onto the cutout, trying to reproduce the thickness according to the gap around the perimeter observed earlier.

Caulking Hole Perimeter

Now ease the port in place, trying not to push the caulk out of the port, and working as
quickly as possible, fasten only enough screws to hold the port in final position

Placing the Port in the Hole

Working quickly before the caulk takes its initial set, gun the space solid between the
cutout and port frame. The silicone can be pushed considerable distances when it is fresh
and hasn’t skinned over.

Caulking Annular Space Solid

The inside of the trim ring is now caulked with a generous double line of caulk

Caulking Outside Trim Ring

The trim ring is next pressed against the cabin trunk pressing just hard enough to see the
caulk squeeze out in a continuous line entirely around the perimeter of the trim ring both
inside and outside. More caulk will be needed on inside of trim ring to caulk the joint flush with the protruding portlight barrel

Completing Ring Caulking

With the inside of the trim ring caulked solid and the excess caulk wiped completely away.
the remainder of the inside screws can be driven home

Cleaning Up Excess Caulk

New portlights look a lot cleaner for not having all of the essentially non functional
outside trim screws. The silicone alone is adequate to secure the trim ring against
the cabin trunk.

Finished Installed Port

Click image for largest view