Looking online I am getting conflicting dates.

Anyone know what year they started zinc coating the 911?

I am looking at 1980 911SC euro, and wondering if this was zinc coated or not.

Thanks.

 

The real experts will soon chime in, but if I'm correct, they began galvanizing the entire body around 1976.

Yes, your SC was fully coated, but of course the possibility for rust still exists, so get it looked at.

The windshield surround and under the battery tray are particular areas to be aware of.

Good luck

 

Yes 1976 was the year...galvanized

 

I thought mid year 75 they began doing the bottom half. Can't recall when the full body galvanization started.

 

'73 through '75 cars received hot galvanizing on the bottom and sills, full-dip galvanization began in 1976.

Remember though, zinc is a sacrificial element in the corrosion prevention process so after 25+ years, a lot of that protection is gone depending on where the car has lived. Any car of this vintage should be thoroughly inspected for rust, depending on its locale.

 

much thanks guys!!!

 

Porsche begun offering a ten-year anti-perforation guarantee on their 1976 cars, finally galvanizing the entire body shell by that time. In 1975 they had galvanized all but the roofs. (Why that was done is beyond me!) As Steve mentions--zinc is sacrificial, and thus, much is lost over the years.

Galvanized bodies added considerable complexity to the 911 body (and expense) because the 5,000 welds had to be done at very precise temperatures. Too hot, and you literally burned off the zinc. Too cool, and the weld was inadequate. Ideally, the weld effectively joined the two steel parts, and then liquid zinc would flow back over the weld location, sealing it off from the elements. Keep this in mind if you have any metal work to do in the future.

 

"Galvanized steel was in use since the 1971 models, for body parts particularly exposed to rust, but from 1976 models on the entire body was assembled from steel sheet protected on both faces by a layer of zinc the thickness of which varies from 10-20 Thousands of a millimeter, according to the conditions to which it was to be exposed. Only, and for one year only, the roof was not galvanized because units of that size were not available at the time. Porsche was the first car manufacturer in the world to offer such comprehensive rust protection and it took 10 years for another -- Audi -- to follow." Paul Frere; Porsche 911 Story, pg 201