Frosted Windows - Does Anything Work?

[ztsf]

I recently purchased a sailboat with two fixed (plastic) windows in the hull. The windows seem to be abraded on the top half of each. I'm assuming this was caused by salt spray funneling back along the side of the boat when heeled. Before launching at the end of last season, the yard I was in tried some buffing compound and a rotary buffer (the kind you would use to wax the side of the boat). It didn't make a dent in abrasion.

I'm wondering if anyone has faced a similar challenge and what (if anything) worked short of replacing the windows (which will be a big bill on this boat as they are totally glassed in).

Photos attached

[gulfstar37]

May want to try going to automotive store. Ask for headlight polish kit. This is for the plastic body lens covers that will get cloudy over time. Does take some time to do though.

Good luck

Sent from my XT1080 using Cruisers Sailing Forum mobile app

[Exile]

I have similar problems of crazing, cloudiness, etc. on my portholes & hatches, all made from some sort of acrylic or Lexan. Tried some polishes but they don't seem to work, or if they do it's minimal. But worse, the problem reappears after a period of time. I've been told they all do this over time & replacement may be the only option. Much bigger job when they're embedded in the hull like yours, obviously. Maybe someone else will come up with a better solution. There are also other threads on this topic you may want to check out.

[osirissail]

The crazing in the plexiglass is due to the sun's UV drying out the surface of the plexiglass/Lexan/etc.

There two ways to deal with the crazing - 1. remove and replace with new, and 2. use mechanical sanding to remove the top layer with the crazing and then use finer and finer sand paper until you can use "plastic" polishing compound and buffs to restore the polished surface.

#2 is a very time consuming process so most folks just buy new plexiglass and replace the old crazed stuff.

Keeping Sunbrella covers over the plexiglass (hatches, portlights, etc.) when you are away goes a long way to extending the life of the plexiglass before crazing gets too bad.

[roverhi]

UV causes the lights to craze. Windex and other glass cleaners will also cause crazing and should b never be used on plastic lights . Lexan is very prone to crazing, plexiglass much less so replace with plexiglass if you chose to go that route.

As others have said, pol!ishing away the crazed surface is the only fix.

[Steve Bean]

Has anyone tried gluing a thin sheet of new acrylic or lexan over the crazed surface? My idea is that the clear solvent cement would fill the cracks.

[osirissail]

Lexan is used on hatches and horizontal surfaces as it is considerably stronger than acrylic plexiglass. So be very careful if you replace the plastic in a horizontal hatch or anything that could be stepped on by somebody. The manufacturers are very wary due to liability problems so they normally use Lexan on hatches and portlights that can be stepped on.

Otherwise, the last acrylic plexiglass that I purchased to replace vertical cockpit windows came with a 10 year guarantee for yellowing and crazing -and- the previous installation of the same material did last almost 11 years before it got too much crazing to see through.

[Exile]

Originally Posted by osirissail

Lexan is used on hatches and horizontal surfaces as it is considerably stronger than acrylic plexiglass. So be very careful if you replace the plastic in a horizontal hatch or anything that could be stepped on by somebody. The manufacturers are very wary due to liability problems so they normally use Lexan on hatches and portlights that can be stepped on.

Otherwise, the last acrylic plexiglass that I purchased to replace vertical cockpit windows came with a 10 year guarantee for yellowing and crazing -and- the previous installation of the same material did last almost 11 years before it got too much crazing to see through.

Thank you! This reminds me & explains info I got from Bomar/Pompanette a couple of years ago that my hatches were made from Lexan & the portholes with acrylic. Other than cost, is the only reason to use acrylic vs. the stronger Lexan in portholes is that acrylic will last longer before crazing? Or does it have to do with the fact that vertical surfaces are subject to more flexing? If you know . . .

[UNCIVILIZED]

Originally Posted by Exile

Thank you! This reminds me & explains info I got from Bomar/Pompanette a couple of years ago that my hatches were made from Lexan & the portholes with acrylic. Other than cost, is the only reason to use acrylic vs. the stronger Lexan in portholes is that acrylic will last longer before crazing? Or does it have to do with the fact that vertical surfaces are subject to more flexing? If you know . . .

How often to people step/jump on portlights? = Might be your answer.
That said, waves slam into portlights/boats fall off of waves onto portlights far more frequently, so... Still, portlights are like 20% of the area of a deck hatch.

For my money, I'd prefer tempered glass in a portlight, or barring that, Lexan with a scratch protective coating. Or even better, than both, a laminate (tempered glass & other clear glazings, AKA bulletproof & then some).

Most of your answer lies with the "bottom dollar". IE; how cheaply manufacturers can get away with making the product, allowing for a "reasonable" failure rate.
That, & it's a bit easier to polish Acrylic, so in a portlight, which folks tend to look out of, unlike deck hatches, something "buffable" wins.

[CharlesV]

I was going to say its the classic headlight sanding problem. You dont need a kit since you most likely have the materials at hand, but you should review the headlight renovation procedures on youtube for best results.

[osirissail]

I would agree that "tempered glass" would be the best for "prism" type portlights -or- the old fashioned bronze portlights/portholes. However, the glass would have to be cut specifically by a glass shop and that would be expensive.

But for opening (sidewall) portlights/portholes acrylic plexiglass would be a good choice providing the portlight/porthole is made of flat plexiglass and not a shaped special type of opening porthole. Some cruisers have special lexan panels made to cover over their portholes/portlights/windows on the sidewalls for protection from heavy weather/waves when underway.

But for the deck or horizontal hatchs, etc. Lexan is the way to go simply because people step on them - usually unintended by tripping or losing their balance with boat motion. That type of impact from a 180lb +/- person can fracture acrylic plexiglass.

Coated plexiglass is available but considerably more expensive. I investigated it years ago when I was building my pilothouse and the material is used for "hocky-games" surrounds that protect spectators from flying pucks and players. But boy, it is expensive.

[Exile]

Originally Posted by UNCIVILIZED

How often to people step/jump on portlights? = Might be your answer.
That said, waves slam into portlights/boats fall off of waves onto portlights far more frequently, so... Still, portlights are like 20% of the area of a deck hatch.

For my money, I'd prefer tempered glass in a portlight, or barring that, Lexan with a scratch protective coating. Or even better, than both, a laminate (tempered glass & other clear glazings, AKA bulletproof & then some).

Most of your answer lies with the "bottom dollar". IE; how cheaply manufacturers can get away with making the product, allowing for a "reasonable" failure rate.
That, & it's a bit easier to polish Acrylic, so in a portlight, which folks tend to look out of, unlike deck hatches, something "buffable" wins.

OK, I have my answer thanks, at least b'twn the choice of Lexan vs. acrylic. I thought perhaps Lexan wasn't as flexible & thus not as good a choice for portlights along my cabin sides, but it sounds like it's mostly a function of cost. With 16 portlights on my boat, I would imagine the cost difference b'twn the two would be incremental compared to the labor.

Thanks for the info.

[hamburking]

I had a similar problem...My boat windows were so opaque I didn't need curtains! Then a fellow cruiser showed me a product...I was skeptical, but it really worked...with very little effort, my windows looked brand new again. Seriously. The product is called FLITZ. I don't know if they still make it, but it was like magic. The only drawback is that after a few weeks, the windows go back to like they were, until you apply more FLITZ. Its like a glossy wax that fills in the scratches. FLITZ.

[hellosailor]

If you have to assume, assume it is acrylic (plexi) not polycarbonate (Lexan) because lexan is damned expensive and rarely used.


Your best bet is to look for Novus polishing products:


http://www.amazon.com/NOVUS-7100-Pla...WW10QKCCH8RT89


Probably the best name in the business. You start with the coarse polish and an electric wheel of the proper speed and material, worh your way to the medium then the fine grades. It WILL restore a factory finish as long as the haze you are seeing is just on the outside, which it appears to be, rather than crazing, etc. that goes all the way through the material.


The stuff works, as long as you follow directions and use the right wheel with it.


After that? I'd suggest making a point to wash down the glazing frequently with just fresh water, and a fine polish once in a while, before it looked like it needed any.

[Steve Bean]

In 1982 I replaced six 18" square deck hatches on a 61-foot ketch. The original glazing was acrylic and very crazed. A painter at the boatyard had tossed a gallon can of paint onto the deck and it crashed right through one of the acrylic hatches! Time for replacement!!
The original installation involved drilling and tapping 20 or so holes for #10 machine screws in the acrylic. There were cracks at every screw as no allowance had been made for differential expansion between acrylic and stainless steel frame. The skipper insisted that I use the same wrong procedure. I used 3/8" Lexan, drilled and tapped, sealed with silicone. In the process of drilling the stainless for new dogs, I heated the frame enough to cause a crack in the Lexan. The skipper wanted to test it on the boat for strength, so we installed it and the skipper, a husky 180-pound 28-year-old, jumped up and down on it as hard as he could. This caused only a slight flexing. Then he struck it several times with a car wheel, just the steel part, causing some small marred spots. I doubt that 3/8" acrylic would have survived this test; it doesn't have the resilience of Lexan.
I want to try out my idea of laminating a thin piece of Lexan onto some weathered Lexan that I have. I'll report my results.