How to make a Kayak portal cover?

I lost the portal cover for a Boreal Design Narwhal front Portal. Red fibregalss.
It is an odd shape around 14"x13"x10"x13" - squarish pan shape.
It is discontinued by the manufacturer and they do not have any replacement covers.
Does anyone have any suggestions for making a replacement portal cover?
How hard would it be to make a fibreglass one?
Would a plastic be easier without much weight difference?
Would a rubber one be feasible? The current ones are hard shell fibreglass.
The sides of the cover are rounded, the cover extends over the flat lip around the portal and bends down into the gutter around the portal. A gasket runs inside the rounded edge of the portal to reduce water access.

If this was my project, I would order this conversion plate from Topkayaker and cut it to overlay the opening completely, drilling it to attach with stainless steel fasteners with a gasketing material all around. Then cut out a round opening in the center of it and install a round screw-in hatch to gain access to the hatch space (Topkayaker has plenty of those as well.)

Depending on where you live, you might be able to find a shop that custom makes small fiberglass parts, like fenders and fairings for motorcycles and sports cars, who could fabricate a replacement hatch.

1 Like

Thanks willowleaf. Will consider topkayaker hatch patches. I am hoping to avoid drilling and modifications to the Kayak, however I may end up needing to do more and will consider this.

I would try making a cover out of wood. First, make a simple rectangular frame that just fits around the outside of the rim on the kayak. The sides of the frame are straight while the front and back parts are cut on a curve to match the curve of the rim on the kayak. Then glue a thin sheet of plywood (like the okuma plywood used for kit-built kayaks) to the top of the frame. That will give a you a hard cover that matches the curve and can be held down with the existing straps. And if you finish it well, it could look just as good as a fiberglass cover, or you could fiberglass over it. Stick-on weather stripping on the underside of the new cover might be sufficient for a seal.

You could also make a similar shape out of wood to use as a mold to form a fiberglass cover. But I’m not familiar with all of the steps required, such as how to ensure the fiberglass releases from the mold.

1 Like

Thanks for the suggestion. Have wondered if I could make a cover out of wood. Thankfully I have the winter to work on a solution.

Well I actually found another kayak that has the same portal cover size. I intend to use the other kayak portal as a plug to create a replacement fiberglass one. Sounds like there are two ways to do this. I can use the existing alternate cover as the mold and create a cover using that, or I use the existing cover to create a plug that I use as a mold. The mold is then used to create the actual replacement cover. The second way is the way the pros would do it and would allow future duplication. The first way is the easiest in some ways.
It was recommended that for this the first easier way should be good enough.
To protect the existing portal cover, I was told to wrap it in foil tape to protect the existing surface. Then wax the tape to create a surface that the finished new cover can be removed from. Apply layers of resin and fiberglass over the wax and tin foil taped surface, to get to the desired thickness. The final coat could be some kind of enamel epoxy paint. I wonder if a Gel coat tinted to the red I want would be better? Likely will do the simple paint first and see how well that lasts.

I used 5 layers of fiberglass cloth, trying to have one sheet that covered the whole surface and not a bunch of little pieces.
Prepping the “Plug” (the portal cover from the other boat that I want to make sure I do not damage).
I taped the surface wrapping the tape completely around to the under side with aluminum tape as used in plumbing. It was surprising that the tape was hard to keep it smooth. I also overlapped it to make sure there was no exposed surface and this left small lines where the tape was higher than the other tape it over lapped.
Then I waxed the surface six times using turtle wax I bought from a generic auto store - Canadian tire, walmart, princess auto sell it. It was much cheaper than the professional fiberglass wax. I used a cloth, dipped it into the wax, and then rubbed it across the aluminum taped surface. I did not try and rub it deeply in. I left thick layer across the surface doing this 6 times. I think I left it for an hour or two between each application.
Then I sprayed on hair hold spray - 6 times. This works like fiberglass release wax. hair spray is meant to apply a layer across the hair to hold it’s shape, however if washed it released and washes away. This is the exact nature of the release wax. This again was less expensive and readily available at the local walmart. Again I let it dry between each application. Left it for an hour or so between applications. I then let this dry for a good 24 hours.
Next I painted on the WestSystem epoxy resin 105 with the 206 hardener. Let it get sticky and then applied a single layer cloth that covered the whole surface. I applied the resin hardener mixture with a paint brush over the cloth until it was saturated and smoothed out across the surface and wrapped around the portal edge and hanging down below the edge. Let this dry for between 1 to 3 hours and then applied the next coat. Did this 4 more times and for a total of 5 layers. I had originally planned to do 6 based on the recommendations of some professional fiberglass manufacturers. When I reached 5 it seemed too much so I did not do the 6th coat. The last coat was messy and the cloth did not pay down as nicely as the previous layers. This caused a lot of extra work. I believe the original was either 2 or 3 coats and 3 would have been effective , 5 was overkill. The 5 layers makes this port hole cover heavier and thicker than it needs to be.
I let this sit for 24 hours.
It seemed rock solidly attached to the plug and I was worried it would not come off.
I used a cut off wheel to cut the hanging extra cloth from the lower edge of the plug.
I sprayed water along the edge hoping it would magically float apart. No such luck. Stick rock solid stuck together. I then submerged the piece in water over night. The next day i used a stainless steel putty spatula to pry between the plug and the mold layers. After about an hour of working my way around the edge several times it started to loosen up. After 2 hours it came apart and the plug did not seem damaged in anyway. Phew.
I started the sanding process followed by more layers of epoxy resin, 5 times and still the imperfections were noticeable. I would apply the resin, wait 24 hours and then sand. I believe I would have to do this about 15 times to get to a smooth surface and I was not willing to take this much time. I called a halt at 5 resin/sanding coats.
I had some left over INTERLUX BRIGHTSIDE 1 PART POLYURETHANE-QT fire red that looked close to the kayak color. I am using this to paint the new kayak cover. Will see how this looks after 3 coats.
The next challenge is finding adequate gasket seal material. I ordered some from the web however will take a couple weeks to arrive. I will need the portal cover in 1 week so will not be able to wait for what looks like better stuff to arrive. Will try and find something else to use. A soft rubber tube that can be glued may work. I was also considering everyday window/door sealing gaskets, or even a pool noodle cut to the right size strips to line the portal to create a gasket.
Will see what seems to work.