Portlight Glass

[Exile]

Originally Posted by skottc

For saw cutting we're using computerized panel saws that are made specifically for plastic. With those we can control almost every aspect(rpm, feedrate, blade projection, clamping pressure, hold down pressure, blade cooling...). Of course the tooling is another huge factor, it takes the whole package. We pride ourselves on our cutting.
For people who want to do it themselves, the best method is usually a table router. I actually have a how-to blog and videos on this. We are trying to educate and clear up common misconceptions(like the one about cutting acrylic with the blade on backwards, wholly #*@~!). I'm not going to put the links here because it would be considered commercial links. The forum mod was gracious not to ban me for doing that before(sorry again).

Old thread, I know. Hope you're still around. I've finally decided to replace my old, crazed acrylic ports with hopefully high quality new acrylic. Do you have any sealant recommendations? Somebody already mentioned SikaFlex 295 I think, but that may have been for Lexan. I've also been recommended to BoatLife's LifeSeal (vs. LifeCaulk). Any recommendations for sealant would be appreciated. I'd also be obliged if you might PM me with how I may purchase the acrylic itself from your co. or another reputable source, assuming that's consistent with forum rules, of course. Thanks.

[Jimbo485]

Bump bump

[osirissail]

Originally Posted by Exile

Old thread, I know. Hope you're still around. I've finally decided to replace my old, crazed acrylic ports with hopefully high quality new acrylic. Do you have any sealant recommendations? Somebody already mentioned SikaFlex 295 I think, but that may have been for Lexan. . . .

For an adhesive caulk/sealant for acrylic plexiglass I would recommend the Sikaflex-295UV and its companion primer 209-N to bond acrylic or polycarbonate plastic to window frames. I used it to "glue" in my cockpit windows into aluminum frames and it lasted 10+ years. Actually the acrylic plexiglass crazed and became barely transparent while the Siks-Flex was still holding everything together. Bitch getting it out so I could install new window panels.

Anyway, I think it is the best product - but - only if you use it correctly. That is the frames need to be very clean; I recommend scuffing or sanding the half inch of plexiglass edge that will be buried in the frame before applying the primer. Then you need to "float" the plexiglass on a bead of the Sikaflex 295UV so that the plexiglass is "captured" by the adhesive/sealant and can move as temperature and boat motion caused the window to expand and shrink. If you do not allow for expansion/contraction and movement of the plexiglass you will end up breaking the seal and water might work its way in.

See: http://usa.sika.com/dms/getdocument....%20Windows.pdf

[Emmalina]

Great info everybody. Just making some new stainless portlights to replace some very leaky wooden ones and have got a sheet of 15mm tinted acrylic... Me and glass never got on since i was big enough to throw stones...:-)
Anyway have enough to make lots of spare panes so not too worried about crazing...