When did Galvanized bodies start?

[nameisbauer]

I read in some places 1975. Some in 1978.

"In mid-1975 Porsche began dipping its formed sheet steel body panels through an electrically charged 930 deg. bath of zinc. At this temperature, the zinc bonded galvanically to the steel. Every steel surface in the car body was "galvanized" at a manufacturing cost of nearly $100 per car (1975 911S base cost $11,875)."

If this is true, how do you tell which 1975 models are and which are not?

[DUK]

Galvanizing on Porsche 911s - A History

[Porsche-O-Phile]

If it's rusted, it's not galvanized.

Galvanized metal looks different. If you chemically strip the paint off, galvanized panels will have a bit of a "scaled" look to them. Smooth, but slight variations in coloration (usually little square-ish shapes around 1cm-2cm across). Regular metal looks more uniform in coloration/appearance.

[island911]

the short answer is, Porsche slppery-sloped the galvanization of the bodies. Being that it adds cost and weight, the early 70's had just the floor panels (and some bits) done, and by the SC they were fully galvanized. --IIRC

[nameisbauer]

Thanks guys, I wish that original history came up when I searched.

1970 – Galvanized steel (not Thyssen type) used in floor pan and wheel arches (Bob White in Pano V: 142); the “entire platform, including the floor, the longitudinal members, the wheel arches and the seat pans were galvanized.” (Boschen & Barth, p. 124)
1971 models – had galvanized steel in areas particularly exposed to rust (Frere, p. 201)
1972-1973 – Thyssen steel use began (Bob White in Pano V: 142)
1973 – Thyssen steel: rocker panels, inner rocker panels, floor pans, & some other parts (Chuck ******** in Pano V: 142)
1975 – Thyssen steel: entire body treated (Bob White & Chuck ******** {began in Feb. ’75 production for US cars; earlier for Euro cars – had trouble with paint} in Pano V: 142, 192)
1976 models – had Thyssen steel in entire body except roof (Frere, p. 201)
1977 models – on – had Thyssen steel in entire body (Frere, p. 201); an “important step forward was the use of zinc-coated sheet steel for the manufacture of the entire body structure (except for the coupe’s roof on early production cars). Coated on both sides, this made the structure virtually immune against the formation of rust….” (Boschen & Barth, p. 143)

[RWebb]

what search terms did you use?

you could add them to the thread -- I made up the thread b/c this is a pretty common question. so it would be nice if people could pop up the researched answers quickly

[jkh2cpu]

Name is Bauer is on the money. My factory manual says on the top of page SB 39: Beginning with 1970 models, the vehicle undercarriages are made of galvanized steel and sheet metal sections.

Vehicles with the following chassis numbers are excluded:

911 012 0011 to 911 012 4126 and

911 022 0011 to 011 022 06667

911 112 001 continuing

HTH.

[Hesse James]

Hello,

However galvanisation was a big step into the right direction. Especially when Porsche came up with it in the late 70ies. In Europe at that time nearly the whole car industry used steel from minor quality (recycling steel coming from eastern countries) that lead to severe rust problems especially in the mid 70ies. Cars from that period of time started rusting when sitting and waiting for delivery to the customer.
But galvanisation does not mean no rust. If the surface is not proper sealed, it will rust like any other non galvanised steel - only later, if all the zink-galvanisation is gone. You can see it whwn you look at old rail-guards that are fire-galvanised but not coated - after the surface is gone, rust will appear. Same with old porsches - especially if the surface is not conserved or painted, poor repairs or welding after accidents and so on. I've seen so much galvanised SC cars in Germany that wre fully rotten by permanent driving on salty roads. Those cars look like a non galvanised car - only 20 years later. So everybody should be aware, that all porsches - galvanised or not - are subject to corrosion (especially because those cars are kept longer on the streets). If you live in a region with salty roads in winter, or dirctly at the sea - you should take action to preserve your car - or you should not drive your car in such conditions.

best regards

HEiko