Grr! Still trying to get link to work. Try this link:
https://drive.google.com/drive/folders/0BwQRSP2fYIFmemxYOGlVcHNUNVk Gary ~~~~~~~_/)~~~~~~ On Wed, Dec 2, 2015 at 8:57 PM, Gary Russell <captnga...@gmail.com> wrote: > Oops! Try this link: > > > https://drive.google.com/folderview?id=0BwQRSP2fYIFmemxYOGlVcHNUNVk&usp=sharing > > Gary > S/V High Maintenance > '90 C&C 37 Plus > East Greenwich, RI, USA > > ~~~~~~~_/)~~~~~~ > > > On Wed, Dec 2, 2015 at 8:47 PM, Gary Russell via CnC-List < > cnc-list@cnc-list.com> wrote: > >> For those who were following my post on bonded windows on High >> Maintenance, I have an update and many thoughts on the project enumerated >> below. I have successfully installed two windows on the starboard side and >> replaced the acrylic on all the hatches and can say that the project has >> been very successful. I have terminated my project at this point as the >> temperatures are now too low for the VHB tape which requires a temperature >> of greater than 60 degrees F for application. Here are my observations: >> >> >> >> #1. Plexus is evil stuff and should not be allowed on a boat. It is too >> hard and tenacious a bond. Because fiberglass and acrylic have such a >> different expansion coefficient, fracture of the acrylic is assured. >> Removing the stuff is impossible without destroying the gel coat >> underneath. I tried a sharp blade between the fiberglass and the acrylic >> and all I managed to do was rip up the gel coat. >> >> >> >> #2. Before removing the windows, make a template out of some thin >> plywood (or other material) because the window will (no doubt) come out in >> pieces and you will have nothing as a reference for making the new windows. >> >> >> >> #3. I finally was successful removing the acrylic with a 5/8” router bit >> set to a depth equal to the thickness of the acrylic plus the thickness of >> the Plexus. I actually used a Roto-Zip instead of a router as it had a >> smaller footprint and was easier to handle. I free-handed the router to >> cut through the acrylic and into the Plexus. It’s risky but effective. >> Don’t cut all the way around the perimeter, but leave tabs to support the >> window. Otherwise, the window will sink under the weight of the router and >> you will cut into the gel coat. You can break out the tabs later. >> >> >> >> #4. Once the windows were out, I used West System epoxy thickened with >> low density filler to repair any damage to the gel coat. Fortunately, all >> my gel coat damage was limited to the area under the windows. Once the >> windows are out and the damage is repaired, the rest is fun and easy. >> >> >> >> #5. I cut the new window out of 3/8” Plexiglas using a pattern router >> bit (sometimes called a Formica trimmer). I used masking tape folded in >> half lengthwise to stick the new Plexiglas to the old window (or >> template). I ran the tape at right angles to insure that they wouldn’t >> slide in either direction with respect to each other. It does a very nice >> job and is quite easy. I then used a 1/8” round off router bit on the >> outside edge of the new window for cosmetic reasons and a 45 degree chamfer >> bit on the inside edge to make room for the Dow Corning 795 silicone. >> >> >> >> #6. I installed the 3M VHB 4991 tape on the coach roof and masked around >> where I wanted the window to go. This would help me locate the window and >> provide the masking for the Dow Corning 795 silicone to follow. I also >> masked the edge of the new window for the same reason. >> >> >> >> #7. Now cones the tricky part. You only get one shot with the VHB tape, >> because once it is down, it is not coming up. I tried adhering two small >> pieces of acrylic to each other with about two square inches of VHB tape, >> and I can assure you, you won’t pull them apart. VHB is amazing stuff. As >> a guide, I mounted two small wooden blocks to the masking take below the >> window with a small piece of VHB tape. By attaching it to the masking >> tape, I was sure I could get it back off. Actually, VHB doesn’t stick very >> well to masking tape anyway. I also stuck a small wooden block to the >> masking tape at one end of the window as well. This allowed me to set the >> window on the two bottom block and then slide it over to the end block >> before pushing the window into place. By all means, make several trial >> runs with the film still on the VHB tape before removing the film. Once >> the film is off you are committed. I pushed the window in place and it >> looked perfect. Then it is simply a matter of squirting the Dow Corning >> stuff into the gap and smoothing it out with a finger. As soon as the >> silicon is smoothed out, you can remove the masking tape and pour yourself >> a stiff one, while you admire the fine job you have done. >> >> >> >> #8. There was concern expressed that the VHB tape would be visible >> through the window, and it was suggested that the window should be painted >> with Krylon Fusion Black. Actually, the VHB tape is the same color as the >> Plexus which is not visible, so the VHB won’t be visible either. No paint >> is necessary. I used the darker shade of grey Plexiglas and can say that >> it look spectacular. The darker shade really “pops” and the contrast is >> particularly attractive (in my humble opinion). The darker color makes it >> difficult to see into the boat, but has a minimal effect when looking out. >> The VHB is not visible at all. >> >> >> >> #9. There was also concern expressed concerning whether the curvature of >> the coach roof would cause a flexing force to peel the VHB tape. I can say >> that the radius of curvature is very large (>20 feet) and the forces are >> thus very small. 3/8” acrylic over those lengths is quite flexible. I see >> no problem at all. >> >> >> >> #9. I have posted some pictures on Google Drive and I think you can view >> them at: >> >> >> >> >> https://drive.google.com/folderview?id=0BwQRSP2fYIFmemxYOGlVcHNUNVk&usp=sharing >> >> >> >> I am new to posting pictures, so if you have trouble seeing them, email >> me and we can get it fixed. I will add more pictures as they become >> available. >> >> >> >> #10. Needless to say, I am thrilled with the outcome so far. I have >> also re-glazed the hatches using the Boatworks video and they came out >> spectacular as well. The only difference I made from their recommendations >> is that I bedded the acrylic in butyl tape instead of the Dow Corning 795 >> because it was much easier to get a uniform bead and that was the way it >> was done from the factory. I still filled the gap around the windows with >> the Dow Corning 795. Boatworks is right, the Dow Corning 795 is nice stuff. >> >> >> >> #11. If I have left anything out or you have any questions about this >> post, just give me a shout. >> >> >> >> Gary >> >> S/V High Maintenance >> >> ’90 C&C 37 Plus >> >> East Greenwich, RI, USA >> ~~~~~~~_/)~~~~~~ >> >> >> _______________________________________________ >> >> Email address: >> CnC-List@cnc-list.com >> To change your list preferences, including unsubscribing -- go to the >> bottom of page at: >> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >> >> >> >
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