Photos (hopefully) show the starboard chainplates and window on my Precision 23. Usually on chainplates I just wrap MS butyl tape around them then flatten the cover plate down on it. This time. I dug out old caulk putty on forward side.I think the hole is too latlrge for just tape plan to epoxy in the hole then tspe over top unless there is a reason not to. On the window, the forward end last 8-10 inches ID all cosmetic,all F/g behind it. I plan to move sternward about zn inch or so and put a new screw in. I don't know what type of plastic this is and I'm wondering if it will drill safely or spiderweb up on me. Planning a tiny pilot hole first,then widrn it out. Also planning to counter sink into it a little bit to put butyl tape under a large washer under the screw head. Can I get some attaboys,or hell no's?
Chainplates and window sealing
- Thread starter DAVA390
- Start date
I wouldn't put epoxy around the chain plate. Any movement of the chainplate will crack the epoxy or even worse create a hard spot and weaken the chainplate. If you are not happy with filling the area with MS butyl, try filling the area with Life Calk or something similar, let it harden, then put the butyl under the plate.
I agree. Don't think that gap is so large. You might cause more cracks if you make the opening too tight.
I think you do not need screws for the window. The screws are usually used to hold the window in place while the adhesive (dow 795 is the usual glazing) dries. Once the adhesive dries, you can remove the screws, as they often end up causing cracks and breaks in the plexiglass. The screws do not move with the plexi like the glazing does, so they sometimes cause cracks.
In your case, the adhesive is dried. You can remove the screws and seal them with adhesive.
I think you do not need screws for the window. The screws are usually used to hold the window in place while the adhesive (dow 795 is the usual glazing) dries. Once the adhesive dries, you can remove the screws, as they often end up causing cracks and breaks in the plexiglass. The screws do not move with the plexi like the glazing does, so they sometimes cause cracks.
In your case, the adhesive is dried. You can remove the screws and seal them with adhesive.
Your window is surface mount on the Precision 23. The screws are only there to hold it in place while the original silicone sealant cured. They aren't really structural, and it's pretty common for the end corner to break like that. Based on your picture, unless you've got leaks around the window, leave well enough alone. On mine, I had leaks because the screws went into NON-countersunk pilot holes in the fiberglass, and over time, spider cracks spread out from the fastener hole, underneath the sealant, and just a wee bit beyond the sealant, so that water could seep in through the crack behind the sealant. That, combined with crazing, led me to replace the windows entirely. I did it without fasteners or holes through the plexi, using 3M VHB acrylic foam tape, sealed by Dow Corning 795. When I took the old windows off, nowhere did I find the original sealant had failed, it was just those damn spider cracks. Looks right slick with no fasteners now. My instructions for this: http://www.sailmagazine.com/diy/ask-sail/replacing-fixed-portlights/ and I used high temperature silicone exhaust paint from auto parts store to paint the overlap on the windows. I know someone who had windows replaced on Precision 23, and the yard did NOT paint the overlap, and you can see the beads of silicone they used to glue back on. The yard also used screw fasteners. Let me tell you it looks like amateur CRAP. I would not have paid the yard for that lousy job.
I think mine look pretty good:
I think mine look pretty good:
I agree yours are sharp! replacement is on the someday list and I had planned on adhesive with no screws then. I saved the Don Casey article to the favorites list for then, thanks forth that. I am getting a small leak now, every spring I snug up the top screws a little (not too tight) and drizzle a little Capt. Tulleys along the top of the window. The next back screw that is way out no longer has any bite to it so I`m planning to fill that hole in then retighten it. If that works for the leak I`ll just leave the forward hole alone.
The problem with silicone (maybe other sealants as well) is you don't want 3-point adhesion. Think of pulling a sheet of rubber band from then ends. Stretches nice, don't it! Now grab from the ends and the middle and pull, You'll need Annie for this one. The middle distorts and your hands are twisted slightly (and Annie gives you the WTFAYUTN?!?!!? look. You know the one). In the silicone sealant world this may cause the silicone to rip. That's why us glass guys use backer rod. On the chain-plate, I'd stuff backer rod into the crack, almost flush with the deck. Clean the surfaces with Xylene. apply a 1/4" bead of silicone then tool it with a finger so it goes about 3/8" up the chain-plate and 3/8" across the fiberglass. Let dry for several days then c'sink the cover holes in the deck slightly. Add the butyl and screw it back in place.
The cracked corner of the glazing is more problematic. Dark plastic glazing expands/contracts 1/4"/10'-0/100 degrees. So, a 5'-0, installed at 50 degrees will be 60 1/16" long at 100 degrees and 59 15/16" long at 0 degrees. So, you figure if it's pinned in the middle it will move a minimum of 1/32 in either direction. If your holes aren't over sized appropriately, that puts some serious stress on the glazing . . . POP goes the weasel!
The cracked corner of the glazing is more problematic. Dark plastic glazing expands/contracts 1/4"/10'-0/100 degrees. So, a 5'-0, installed at 50 degrees will be 60 1/16" long at 100 degrees and 59 15/16" long at 0 degrees. So, you figure if it's pinned in the middle it will move a minimum of 1/32 in either direction. If your holes aren't over sized appropriately, that puts some serious stress on the glazing . . . POP goes the weasel!
I don't think you need backer rod around the chainplate. But do not use silicone - it should be used for ports only on a boat. Butyl will work fine.