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| old screwed on ports |
All of the fixed ports on my LF38 were in ruff shape. They were all screwed in place with stainless screws and finish washers. One of the port was actually split in two with a nice vertical 1/8" gap separation. They leaked and were duct tapped until it was time fix them.
They were made of 1/4" thick grey Lexan. I decided to stay with polycarbonate. In my opinion, the benefits out way the negatives. Polycarbonate is much easier to cut, sand, and work with. Acrylic chips and cracks more aggressively. As for the negatives, the cost of polycarbonate has come way done and it now comes in a UV and scratch resistant stock(see below).
Replacing the ports is easy, preparing to do so is a chore. The cabin top surface should be extremely clean and smooth. Having a cabin top which was in the process of being painted went in my favor as I was not afraid to sand, clean, fill, sand, clean, epoxy, sand, and clean. A Dremel and sanding drums worked well here(you can get a bag of 25 sanding drums for a few $ from McMaster-Carr).
To replace the ports, I pretty much followed the procedure outlined by Don Casey in Sail Magazine (link below) on the section for frameless ports via 3M VHB tape. To add to Casey’s article, I traced the old ports and cut the material for the first port with a sabersaw and the others with a band saw. Both worked out fine, but the later was much quicker and easier. I then sanded down the edges and sanded down the inside corner-edge on a belt sander(I later used a router table which worked out nicely). Removing the inside edge was done to help the adhesive/sealant flow better around the seam. This worked easily and produced nice results.
Leaving the protective film on the ports, I aligned the ports in place and traced out the inside lip. Removing the port, I gingerly cut along the inner tracing with a razor knife and removed the outer film. The exposed area was lightly sanded with 400 grit paper and painted with one light coat of black Krylon Fusion. The Fusion paint forms a mask around the edges so that the VBH tape and the Dow 795 are not visible through the window. Also, the Krylon Fusion acts like a bonding primer promoting adhesion. After letting the paint dry, I added the VHB tape on the painted surface aligning the tape to the inside edge making sure that there was at least 1/4" of space on the outer edge.
Then the port was realigned in place. When I was happy with the spacing, I ran two wide, equally spaced, pieces of masking tape down from above the port onto the port. The tape held the port in place and also let me lift it up like it was hinged so that I could then remove the protective cover from the VHB tape. Once done, I then gently swing down the port and stuck it in place. After fixing the port, I masked off the cabin top and applied the Dow 795. Using the wet finger trick, I smoothed out the seam, cleaned up, and then removed the masking tape and protective film from the port.
See Don Casey's article for more details. Here is a link to the article.
http://www.sailmagazine.com/boatworks/replacing-fixed-portlights
Material:
measurements: 1/4” thick with ruff cut sizes:
2@9”x42"
2@9”x52"
I also found great prices for acrylic/lexan at eStreet Plastic. I used 3M VHB #5952 tape (1/2" & 3/4") and Dow 795 both which I purchased from McMaster-Carr(item numbers: 8127A22, 8127A23 & 7452A21), and I sprayed the under-side, unmasked area with black Krylon Fusion spray paint from Ace hardware.
EStreetPlastics.com
2 ea - 1/4" x 10" x 43" transparent grey polycarbonate: $34.98 ea (plus shipping)
2 ea - 1/4" x 10" x 53" transparent grey polycarbonate: $48.98 ea (plus shipping)
Extended Abrasion and UV resistance
Makrolon® 15 sheet is a polycarbonate product that offers high impact resistance, weathering life, and optical quality. It provides a clear aesthetic advantage over wire glass and metal screens for security glazing. Makrolon 15 withstands vandalism, forced entry attempts, and accidental impacts to minimize the risk of theft and glass replacement in damage prone areas. Advanced manufacturing technology has resulted in high optical quality with minimal distortion in clear and standard glazing tints. It has an abrasion resistant coating that provides up to twice the life of prior polycarbonate sheet products. Makrolon 15 sheet has a fifteen (15) year Limited Product Warranty against breakage, yellowing, and loss of light transmission. The terms of the warranty are available upon request.
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| polycarbonate from eStreetPlastic |
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| using 3M VHB tape to fix a port |
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| two ports ready for DOW 795 |
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| first completed port |
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| new ports 3 months later |
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| new ports 3 months later |
