original glass?

[1935Packard]

I noticed yesterday that three of the four windows on my '35 roadster have an etching in the bottom corner that says "Safety Plate," with a "3/35" etched in next to it. (If you want the detailed version, the etching says "SAFETY" on top of a box that has something like "S/O/P" or something like that inside the box, with "PLATE" below the box, and the "3/35" next to it.)

I gather these three windows are original to the car, as I think the car was probably built around June of 1935, and "3/35" would be about right for the windows. Is that right? If that's right, is there a safety issue with having safety glass that goes that far back? I don't know if safety glass has improved much since 1935. It's probably not a big issue, especially as the front windshield was recently replaced, but I thought you all would know.

[Restorer32]

I would think it would be safe. We recently replaced the windshields on a '39 Super that had the original date etching as you describe. Not to steal your thread but was your glass tinted? The '39 glas was tinted. Wondering when tinted glass first appeared in autos?

[Guest imported_Speedster]

The original Safety-glass used in my '29s windshield appeared to have the same strength and durability as newer Safety-glass. (I determined that by: since It was cracked and discolored, I broke it up to put in trash) So they had good Safety-glass, Even back then.

[1935Packard]

Thanks, guys. Pretty impressive that 73 year old auto glass is still safe and in good shape.

Oh, and Restorer32, no, my glass isn't tinted -- it's clear.

[Guest TJOaks]

The glass in my 1936 120 was tinted and I thought that it had been replaced at sometime. To my surprise, I found the dates in the lower corners and it was the original factory glass with tint. I am curious as to when they first started installing tinted glass.

[Owen_Dyneto]

The "tint" that you're seeing is the gradual deterioration (discoloration) of the inner plastic layer. I'm quite confident that there was no tinted glass in Packards until Solex came along in 1951.

[Restorer32]

Owen, that's what I thought too, but my very experienced glass guy insisted that the glass was tinted. It really doesn't look like laminate discoloration or deterioration.

[Guest imported_Speedster]

Is it a Green, Gray or Yellow tint?

[Restorer32]

green tint

[Guest imported_Speedster]

Okay, I don't see how Green could be Discoloration.

I've seen plenty of Yellow discoloration, tho. (Even to Brown)

[Clipper47]

Old glass bottles or telephone wire insulators etc. exposed to years of sunlight typically "tint" to blue, green or purple depending on the amount of copper, magnesium etc. in the sand used to make the glass. Perhaps that is what has happened in this case?

[Guest imported_Speedster]

I've seen the blue-green Insulators, I just assumed that was the color they always were ?

Is the green color, in the windows, the Glass itself, Or the material between sheets of glass, as in Safety-glass and true tinted-glass ?

So, if it's plate-glass and not Safety glass, then it's possible that it could change to a Greener color, with age?

[ProSource]

Hi, our family has been in the auto glass business since 53, in the classic and antique end since the 1970's when restoration became big.. I have some Packard glass here and we have sold quite a bit over the years (Lo-Can Glass International 1953-2002). I can tell you tinted glass came out before the 1950's. It would be a green tint. We actually have the 51-52 Coupe/ Sedan windshields here NOS and we have a couple of NOS backwindows for 40's Packards..

Anyways, the plate glass is different from tempered glass in the way it can break off into pieces. I am not sure when they went to tempered glass. If it is safety plate it would be very similar to laminated glass which is the replecement glass. I do think there was tint with the green hue process certainly in the 40's not sure before then. The laminate is still similar although probably slightly thinner nowadays as to what was originally in there.

All the glass is available for replacement cut to pattern from originals NAGS patterns if any interest. Not trying to do a big sell here but always interested in providing info and keeping the cars on the road . Thanks, RIchard

[Guest imported_Speedster]

Richard,

Thanks for the Info.

[Owen_Dyneto]

After reading ProSource's comments, I've got to rethink my earlier response. Remember the Brunn-bodied formals of 1939? - they had small narrow eyebrow windows over the windshield and they were tinted, green as I remember. Don't know if they were safety-laminate or not.

[Guest imported_Speedster]

I think the main difference is that before the '50s the Tint was in the Glass itself, then after '50 the Tint was in the plastic laminante in safety glass?

[55clipper]

Not wanting to hijack this thread, but since you are in the business, can you confirm or dispute the rumor that the Tri 5 Chevy gasket, either front or rear, is a fit for the 55 Packard?

Thanks,

John

[ProSource]

That I don't know. Someone maybe at Steele Rubber Products or maybe Kanter Products would know that..

[Guest imported_Speedster]

I found this Info which was kinda interesting:

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Most glasses contain silica as their main component and glass former.

Colors in glass may be obtained by addition of coloring ions that are homogeneously distributed and by precipitation of finely dispersed particles (such as in photochromic glasses). Ordinary soda-lime glass appears colorless to the naked eye when it is thin, although iron(II) oxide (FeO) impurities of up to 0.1 wt% produce a green tint which can be viewed in thick pieces or with the aid of scientific instruments. Further FeO and Cr2O3 additions may be used for the production of green bottles or windows. Sulphur, together with carbon and iron salts, is used to form iron polysulphides and produce amber glass ranging from yellowish to almost black. Manganese dioxide can be added in small amounts to remove the green tint given by iron(II) oxide.</div></div>