Portlight Glass

[S&S]

Originally Posted by GWB

Is the autoglass thick enough?

Thanks

Depends on what kind of weather you're planning for. I'd say for general purposes it should be okay.

[GWB]

Originally Posted by S&S

Depends on what kind of weather you're planning for. I'd say for general purposes it should be okay.

Well - I was thinking if a big boarding wave smashed against the portlight, I wouldnt want it to break! You know the saying "plan for the worst and hope for the best"
Anyone know what thickness the ABI glass is from the factory?

[GordMay]

Originally Posted by S&S

... windshields are not tempered, and the side windows are tempered, not laminated...

Thanks, I stand corrected.

[fishwife]

Did anyone mention deadlights? Whatever you go for, do the deadlight thing. When water is pouring through that broken light, you will bless a deadlight. Don't ask how I know. Well, go on then, but get the drinks in first won't you, and will ya kindly swing the lantern as ye pass

Paige

[S&S]

Originally Posted by GWB

Well - I was thinking if a big boarding wave smashed against the portlight, I wouldnt want it to break! You know the saying "plan for the worst and hope for the best"
Anyone know what thickness the ABI glass is from the factory?

Probably not thick enough. Go with the windshield glass and make some plywood storm shutters. I don't think the stock ABI frames will fit thick glass. Ours were made so we got to spec the glass thickness.

Usually production ports just have 1/8" (or less) plate glass (worst of both worlds)

[Kefaa]

A question for those of you who have done it. I have cracked glass (see attached) and a couple of the ports are showing crazing. Is it ports only or is it sufficient for 14+" hatches?

What if someone stepped on it? Does it become like a car window, 1000 harmless pieces, but still 1000 pieces. (I have been told I cannot jump on the windshield to test this. )

To go astray for a moment, they put a vent through the plexi, I am guessing it was easier than the hull (or less nerve racking). Have them cut the same for the auto glass?

[S&S]

With that kind of crack it's acrylic. I wouldn't advise glass for large ports.

[Blue Stocking]

Recently sold my glass and aluminum company.

Glass, in this sort of application, could consist of any combination of 3 types:

a. Float, or plate glass = strength factor 1
b. Heat strengthened = """"""""""""""""""""" 2.5
c. Tempered = """""""""""""""""""" 4

The interlayer PVB (polyvinyl butyral) is usually .030, .060, or .090 thou.
In large laminated lites it is common to use any 2 types so as to gain different shatter characteristics, thereby creating different separation possibilities from the PVB. This is the thought behind "hurricane- resistant" assemblies, or "large-missile-impacted", LMI in building construction.

When cutting holes in glass, the accepted practice is the distance to the nearest edge should not normally be less than the diameter of the hole.

One should always determine what type of glass is being supplied to you.

[Fishman_Tx]

Blue Stocking:
Would it then be desirable to put tempered and laminated in together? Tempered out?

[osirissail]

- - In an environment with frequent waves and rain and lots of UV, trying to put two pieces flat against each other will probably result in sea water or other water ending up between the layers. Not a good situation.
- - My ABI round ports are 5/16" in thick. But thickness would depend upon the orientation of the portlight to the boarding waves. Perpendicular would require stronger equating to thicker glass than oblique where glancing blows are less stressful.
- - for the "triangular long thin rectangular prism port lights I would believe you would have to get replacements from the manufacturer as normal glass shop do not carry triangular prism glass.
- - My Chevy van back home has laminated glass on both windshield and side windows.
- - That hatch has "glass" in it? I didn't think that was allowable under ABYC. Lexan is normally used it is stronger than plexiglass and will flex and recover better when stepped on. Lexan will craze, spider pattern surface and yellow faster than plexiglass but is used where there is a possibility of somebody standing on it. Any holes cut in glass or plastic severely degrades the "strength" in that unless absolutely perfectly edged, the hole will allow minute cracks to grow when under stress loading. I prefer to mount ventilators through the cabin top rather than through hatch glass/plastic.

[Blue Stocking]

Fishman Tx,

A true laminated assembly would be made up at the glass fabrication plant and shipped as a built unit, and would not be cheap. Usually in large units the outer lite is tempered, and the inner heat strengthened. A lot would depend on the size of the lite and the type of risk you intended to expose the boat to.

osirissail is correct in the first statement. I have to say I have always thought that the number of portlights with discoloration around the edges of the glass is way out of proportion to the number of failures we see in building construction, even in shore front installations, where it is standard requirement to give a ten year warranty against manufacturing defect. My 11yr old ABI ports are showing about a 50% failure thru discoloration.

[Fishman_Tx]

That's what I thought. I guess the question now is to either replace the ports @ $189 ea (for the smaller 6 - 4x9) or reglass with plain auto safety glass or tempered. These are the original 1973 issue and are all badly crazed. The boat will coastal cruise initially then the Carib and G of M. No "crossings" in the near or far future for this boat.

[barnakiel]

Our windows are tempered and laminated glass. About 15 y.o. lots of use abuse and going strong.

b.

[Benjamaphone]

The advantages of using glass are somewhat in question around the shop here. First the cost of glass is much higher than even really good quality cast acrylic. The strength is obviously a big factor, but we make up for that by using thick cast acrylic (3/8" or 1/2") and that still comes in much less expensive than glass. Glass does not provide any better of a seal and the risk of shattering or cracking by being hit is higher than with cast acrylic. Also, tinting glass is very expensive and probably not even an option most of the time, whereas it is easy to find tinted cast acrylic.

With a good installation and by using the best cast acrylic, your ports won't need to be reglazed for at least 15 years which is at least very comparable with glass. So basically, we feel that the advantages of glass over cast acrylic are outweighed by the cost, the lack of tinting, the higher weight, and the risk of shattering.

[osirissail]

Laminated glass is quite safe and is normally used in small sizes in areas of the boat where they are rarely subjected to impact damage. Glass will not surface craze as all plastics do. UV will start to craze plastic in a few short years in the strong Caribbean and Equatorial sunshine. Gas will not. Laminated glass is easy to access in most places with a extensive automobile glass shops. Plexiglass and Lexan are not cheap and the more exotic Acrylics are very expensive and difficult to find in small amounts.