I have templates for the C&C 40 windows if anyone needs them. Actually, just a set of old windows the PO thoughtfully passed on to me.
Andy C&C 40 Peregrine On Thu, Dec 3, 2015 at 9:17 AM, Pete Shelquist via CnC-List < cnc-list@cnc-list.com> wrote: > Just an observation; The VHB tape seems like a more simple installation. > However, I’m curious if Plexus is evil because it’s too hard and tenacious, > yet the VHB joined parts won’t come apart, in 5-10 yrs when redoing windows > again it sounds like we’ll be calling VHB evil. > > > > I don’t have a better solution, and question if there’s really a good one > out there. It sounds like we need to keep templates of the lenses and deal > with cutting and filling around the frame when the connection fails. > > > > > > > > *From:* CnC-List [mailto:cnc-list-boun...@cnc-list.com] *On Behalf Of *Gary > Russell via CnC-List > *Sent:* Wednesday, December 02, 2015 7:47 PM > *To:* C&C List > *Cc:* Gary Russell > *Subject:* Stus-List Bonded Windows (continued) > > > > 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 > > > -- Andrew Burton 61 W Narragansett Ave Newport, RI USA 02840 http://sites.google.com/site/andrewburtonyachtservices/ phone +401 965 5260
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