Subject: age of glass
Author: kthinc@dwx.com at INTERNET-PO
Date: 22/01/97 09:13
Ken wrote...
>1) My 1979 registered Spitfire with a factory hardtop has glass
>manufacture dates ranging from August, 1979, to February, 1980. The
>commission numbers indicate that this is a 1980 car according to the VB
>catalog info. Is this anything to be concerned about, or should I just
>forget about it and enjoy driving the car?
This sounds spot on - it is quite normal for glass to be manufactured in
large batches to minimise the amount of tooling changes on-line. Six
months worth sounds OK to me.
A glass production facility is not the sort of place open to the general
public but well worth a trip if the chance arises. I was lucky enough to
visit a modern factory in Sweden last year (on business). I would like
to write a more detailed article for those interested at some point, but
basically once the furnaces are lit (normally gas fired) they are kept
going for up to 20 years without a break. At this point they are shut
down, all the furnace lining (ceramic tiles) fall off and the whole lot
is rebuilt. The furnace temperature, critical in controlling the glass
curvature is maintained by cold, flat glass moving through it, therefore
the plant HAS to be 24hr production. As I said, I'll try and get round
to a more detailed account soon.
>2) Including the hardtop, I have six panels of glass on this car. Five
>of them have the Triplex info. The driver side wing window on the
>hardtop has no markings at all - does this mean that it has been
>replaced?
Not sure to be honest - even replacement (spare parts) glass from
Triplex will be marked. Maybe another (stateside?) manufacturer has
muscled in on this??
>3) The rear window of the hardtop has a Triplex marking that doesn't
>match any of your codes, Pat. The dot is under the "d" on "Toughened,"
>indicating 1980, but the Triplex dot is over the "x." I double-checked
>this, and there is only one dot there. The only other dot above the
>word "Triplex" is the dot of the "i" in the word. Any info on this?
I think your mailer may have screwed up the spacings. A dot under the
'd' refers to a year ending in '9' (1980 would be shown by a dot in
mid-air after the 'd'). A dot over the 'x' is April. Try moving things
around in my original message (making sure you are using a fixed width
(non-proportionally spaced) font.
I'm trying to get official permission from Triplex so that this info can
be permanently available on the VTR homepage. Hopefully I'll be in
touch with Andy Mace in the near future.
Pat
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