Here is my distillation of what I consider to be current wisdom on the subject:
Never use polyurethane adhesives, they *will *debond at some point because the solvents in polyurethane attack the plasticizers in the acrylic. They don't play well together. Do use VHB tape + Dow 740/goo of your choice for pretty trim. A stainless trim piece will hide a multitude of sins. Always use cast acrylic instead of extruded. It is far more stable and less likely to crack from internal stresses. You can use polycarbonate if you want, as mentioned it scratches more easily than acrylic but is stronger under most impact scenarios. It will tear from an edge notch so it does have its weak points. Either can have scratches and surface hazing polished out. I like the Novus products for that. Polycarbonates have fewer tint options. We re-lensed (I just made that up) with a lighter acrylic (2404) and everyone comments on how bright our boat is. That really helps during the rainy season. Here's a good summation of the prep and repair work that can go into the job. You may have to register to see the images (don't accept any candy from strangers). I'm intrigued by the idea of applying a nice frit to the inside to hide the goo. http://forums.sailinganarchy.com/index.php?/topic/133986-how-i-fixed-my-f-ed-up-windows/ Jim Watts Paradigm Shift C&C 35 Mk III Victoria, BC On 21 November 2017 at 16:12, Dreuge via CnC-List <[email protected]> wrote: > Scott, > > I have replaced all of my port and hatch lenses on my boat. For the > hatches, I recommend using acrylic. But for fixed ports, I recommend > using polycarbonate for the replacement lenses. Polycarbonate has a bad > rap because of older variants were more prone to scratching and UV > degradation. The new variants like Makrolon made by Bayer is UV resistant > and extended abrasion resistant. Working with polycarbonate has some > really nice features. First off, polycarbonate is bullet proof strong which > means you don’t need polycarbonate to be as thick as acrylic. Whereas one > might use 3/8” acrylic, 1/4” polycarbonate is plenty thick. It is also > not as brittle as acrylics which means that it is easier to cut, sand, and > shape. Acrylic easily chips and cracks which can turn into creeping > cracks. But more importantly, polycarbonate is much more flexible and > will fit your curvature nicely. > > I replaced my fixed ports almost 3 years ago, and they still look like > new. > > I have a description of my port work on my blog. > > See http://svjohannarose.blogspot.com/search/label/NewPorts > > > - > Paul E. > 1981 C&C 38 Landfall > S/V Johanna Rose > Fort Walton Beach, FL > > http://svjohannarose.blogspot.com/ > > On Nov 21, 2017, at 6:34 PM, [email protected] wrote: > > Date: Tue, 21 Nov 2017 21:59:31 +0000 > From: Scott Baker <[email protected]> > To: "[email protected]" <[email protected]> > Subject: Stus-List Fixing leaky portlights > Message-ID: > <3EF66FAE046FA642ABD7835F36723AB7B997DE30@HEXANDMBX-05.manage-cloud.local> > > Content-Type: text/plain; charset="windows-1252" > > Hi All, > I am still really new in this group and I've not really figured out how to > search through the archives to find the advice I need. > I know this topic has probably been exhausted on here, but I need to > replace my portlights on my 1987 35MKIII. > Some background and my questions: > ~My boat has 2 windows on each side, but they still have a slight > curvature in them. > ~I've watched Andy's Youtube Video where he uses VHB (Very High Bond) Tape > from 3M to install similar portlights. (although no curvature) > https://www.youtube.com/watch?v=MQyjxVUskd8&index=2&list= > PLV97GZkHhpHMFb660AAGO4PuRKJPmHxDS > ~I like Andy's install method but obviously I'm worried about the > curvature issue. Can I induce curve into the windows before I mount them? > If I brace them in place I fear they will pop back "flat" again later? > Solutions? > ~I'm afraid of using screws or through bolts in the mounting proceedures > because of the expansion issues etc... Is this a stupid fear? > ~I've done enough scoping around to learn that everyone seems to have a > different opinion of what the best material is to make new windows out of. > Andy points us towards a specific material and source on his website. > ~I'd like my new windows to be tinted, it seems this would make it hard to > see in and also hide the flange in case it gets mucked up... Yes? > ~I cannot find a good explanation of the best method to remove the old > windows. > ~I think many use the old windows as templates to make the new ones... so > therefore they must be removing them intact? Has anyone mastered the > removal of these windows without hacking everything up? > ~My boat is on the hard and inside a huge shed now in Upstate, NY... Do I > need to wait until it's really warm to do this? Maybe I work on removing > the old windows and cleaning up the mounting areas and put new ones in in > the spring? > Can someone point me in the right direction to find all the answers? > If there is a trick to locating past chats about all this on the C&C site, > I'd love to be edumacated! > Sorry for beating this dead horse. > ~Scott Baker > > > > _______________________________________________ > > Thanks everyone for supporting this list with your contributions. Each > and every one is greatly appreciated. If you want to support the list - > use PayPal to send contribution -- https://www.paypal.me/stumurray > > >
_______________________________________________ Thanks everyone for supporting this list with your contributions. Each and every one is greatly appreciated. If you want to support the list - use PayPal to send contribution -- https://www.paypal.me/stumurray
