crazed plexiglas windows

[dongiulio]

Hello,

The previous owner of my boat replaced the plexiglas windows of my comet, they were just perfect, but now after little more than one year the windows are building up an ugly crazing all over.

Ho can I fix the windows? or protect them from the advancing crazing?

Thanks,

G

[coopec43]

Maybe you should do what this guy does? (I heard you could do it but really didn't believe it)


How to fix crazed acrylic - MySailing.com.au

I've made up fiberglass deck hatch covers to try to stop the crazing and to keep the yacht cool in tropical climates. (I have yet to put latches on the covers)

[dongiulio]

Thanks for sharing this,

Very precious experiment,

In David's experiment he mentions that the crazing is heavier when the glass is in contact with other plastic, my crazing might have been hastened when last spring I inserted a sikaflex gasket in the bolts holding my glass.

Though I heard of people with experience adding uv protecting films and being happy about it.

How can I f figure whether my windows are acrilic or anything else?

[roverhi]

Do not use an ammonia based cleaning agent like Windex on plexiglass or other clear plastic. It will cause them to craze right quick. Best cleaner is plain old soap and water.

[coopec43]

I think anyone with a little knowlege would be able to tell if it was acrylic. The fact that it is crazing would surely indicate it was acrylic? (Does poly carbonate craze?)

http://www.cruisersforum.com/forums/...ss-189386.html

https://www.google.com/search?client...haracteristics

They make it hard!!
Plexiglas. So, what is commonly known as “Plexiglass”, is really a brand of acrylic (PMMA). ... Today PMMA (“plexiglass”) is sold under many different brand names, including Acrylite, Lucite® and Perspex®.Aug 7, 2017

[Dennis.G]

Our ports and hatches are all Lexan (polycarbonate) I believe.

https://coloradoplastics.com/polycar...crylic-lucite/

[roverhi]

Lexan is worse than plexiglass for UV crazing and scratches easier. Unless you need something bullet proof, plexiglass is better for most uses.

[wtmf]

i used Pledge on my plastic motorcycle windshield, a wax. with thst being said a very mild automotive wax may help and lets not forget peanut butter oil to fill the gaps of CD's. OK who wants a to start a start-up company that makes dual pane portholes and windows that has an easy change/throw away outter plastic layer? OR just build the portholes/windows that are easy change, repeat business, plexi and corner the market as the first and sell to the boat manufactures.

[Dennis.G]

Originally Posted by roverhi

Lexan is worse than plexiglass for UV crazing and scratches easier. Unless you need something bullet proof, plexiglass is better for most uses.

Actually had to check, and my memory was wrong, our ports/hatches are actually acrylic. Replaced the large hatch glass over our bed a few years back because of extensive crazing. Put a nice scratch on it the first week!

[Exile]

My boat has acrylic portholes and Lexan hatches (presumably for greater strength). All of my portholes need replacing at this point.

[Paul L]

Originally Posted by coopec43

Maybe you should do what this guy does? (I heard you could do it but really didn't believe it)


How to fix crazed acrylic - MySailing.com.au

....

Yikes, I'm just not man enough to take 60 grit sandpaper to my crazed hatches, as this article suggests.

[Island Time O25]

Wash with mild soapy water to get glass surface as clean as possible. Then 600-1000-1500-2000 grit paper (wet) plus headlight restorer paste from any autoparts store.

Or if you can get cheaply the stuff opticians use to polish lenses that would work even better. Same good effect from glass polishing paste used at watch repair/restoration shops.

Just dont tell those places it's for use on a boat or they'll triple the price to match WM.

[Exile]

Originally Posted by Island Time O25

Wash with mild soapy water to get glass surface as clean as possible. Then 600-1000-1500-2000 grit paper (wet) plus headlight restorer paste from any autoparts store.

Or if you can get cheaply the stuff opticians use to polish lenses that would work even better. Same good effect from glass polishing paste used at watch repair/restoration shops.

Just dont tell those places it's for use on a boat or they'll triple the price to match WM.

I've always heard that restoring them is a temporary fix and that the crazing returns fairly quick. Anyone have sustainable results past a couple of years?

[blubaju]

Originally Posted by roverhi

Lexan is worse than plexiglass for UV crazing and scratches easier. Unless you need something bullet proof, plexiglass is better for most uses.

Sorry, i strongly disagree.

Had both materials on my Catamarans and regret using real Plexiglas on my second, anyway, I must renew them and I will return to PC. PC is not per se UV stable, needs at least UV protective coating, better a scratch resistant coating too.

Acrylic is much harder and according to the producers UV stable. What the heck does this help when after 5 years glazing starts?

I noticed too, wherever sun protection, mesh as well as solid, touched the Acrylglas glazing is worse, seems the softeners in the PVC accelerate glazing, the more vertical windows have less.

We added some acrylic weather protection, a windshield, forgot about the sensitivity to silicone, hence no glazing but cracks at the joining!!

Acrylglas is dead for me, if not for my curved windows, I'd return to laminated glas

[Island Time O25]

Originally Posted by Exile

I've always heard that restoring them is a temporary fix and that the crazing returns fairly quick. Anyone have sustainable results past a couple of years?

Is there a part of the boat that is truly maintenance/worry free beyond 2-3 years? Why would the same owners who wax and polish their hulls EVERY spring would question polishing their plexiglass windows and hatches once every 2-3 years?

BTW, refueling is also a temporary fix. No reason though not to do it on an as needed basis.