Is there some way to galvanize metal?

[Argeo]

I thought I read someplace that someone stripped there car and the galvanize protection from the car and was going to replace it. Is that possible for a DIY or is it the type of thing where the you need to take all the parts off and dip them in some chemical?

Thanks,

David

[sammyg2]

They sell galvanizing spray paint but it's benefits are limited. It's just regular ole paint with zinc mixed in, definately not as good as real galvanizing. That's all I know about the subject.

[RickM]

The auto industry typically uses Hot Dip Galvanizing which is not much of a DIY endeavor. I see Cold Zinc sprays and paints/primers that are used in it's place.

One example: http://www.clearcoproducts.com/cold_galvanize.html

Auto body supply shops will have the appropriate product for an auto resoration.

[Argeo]

Thanks guys.

I guess I am ok then. any piece of metal that I have replaced, I have painted the back side with POR-15 the day before welding in and then before finally sealing up, I have been spraying some protective stuff to try and protect the weld seams a bit. Not as good as real galvanized steal but good enough I suppose.

Thanks,

David

[Scott Clarke]

The steel panels used to make Porsche bodies are galvanized before they are formed. They are galvanized, but this is not a hot-dip galvanizing process. The heat required to hot-dip galvanize would distort the body panels beyond repair.
-Scott

[RickM]

I could have sworn I saw the 911 bodies pulled through a bath of zinc in a video somewhere.....

[RickM]

Perhaps the zinc solution that the car is submersed in is charged and therefore Electrogalvanized as opposed to Hot Dip. ??? Anyone see this part of the production in the Porsche factory tour?

[Scott Clarke]

According to Ludvigsen it is done while the sheets are still flat. Some heat is required to get the zinc to bond to the steel. Galvanizing creates a layer where the zinc is actually alloyed with the steel. Things can be zinc plated, but that is not the same thing as galvanizing. The process that galvanizes the material before it is formed allows the process to happen without distortion of the steel.

Rick-
I wonder if what you saw was some other process that was happening to unibodies that had already been made from flat, galvanized sheets?

[RickM]

Scott, That very well could be. What I found in an industry journal appears to support your correction. Learn something everyday. I'm still curious about what I saw......

Here are some snippets from the article:


"In order to fight the rust caused by the salt spread on winter roads as from the beginning of the 50s, and which were virtually melting away all anti-rust efforts done so far, the automotive industry started in 1955 experimenting with the use of zinc and galvanized sheet to protect the most exposed body parts, the floor and the rocker panels. The first European constructor to adopt zinc protection was Landrover, some 25 years before the entirely galvanized body launched by Porsche* in 1975.


"Wanted. A sheet that is Galvanized one side".
This header from the November 1960 edition of "Steel" illustrates the frustration of the car companies in those days as the markets were unable to provide them with the so-called one-side galvanized sheet they urgently needed: one coated side for anti-corrosion protection and one non-coated side suitable for acknowledged painting methods. This demand finally generated, between 1965 and 1975, new technologies for coating in the steel industry, in terms of both wide-strip galvanizing and pneumatic liquid zinc control, the Jet Wiper* process.

The Jet wiper process, a pneumatic system for controlling the application of liquid zinc to the sheet, allowed the galvanizing companies to enter the market of coated sheet for automotive applications. This process, also known as ‘Air Knives’, invented in the US in 1964, gave regular and smooth zinc coatings of a much better surface quality than those produced with the former coating rolls.

"LIKE "PORSCHE"
After a series of yearlong trials launched in 1967 in order to identify the material of the best quality/price performance in automotive anti-corrosion, Porsche finally opted for galvanized sheet. In 1975, it launched production in series of the 911 with an entirely galvanized body, featuring a seven-year anti-corrosion guarantee.

Zinc had already been present in cars in 1928, in foil shape, but not as galvanized sheet. As a coating metal, it first appeared in carbody immersion processes applied in the fifties and sixties. Its real breakthrough came with the spectacular rise of galvanized sheet as from the eighties on, first as electro-galvanized, then as hot-dip galvanized."


Edited for format and readability

[banjomike]

I have a booklet from the factory about the galvanizing process. The original owner saved it with all the other stuff. I have taken pictures lots of the booklet and I posted them once, but I cannot find that post. When I get home I will try to remember to post them here. I am pretty sure they used an electroplating process.

[Jim Garfield]

The cold galv. spray paint actually works quite well. I painted some raw steel fence parts about 10 years ago with the stuff and have been watching to see how it is holding up. So far, no rust.

The local welder who does fab work for my restoration business, as well as a lot of work on the offshore fishing fleet, swears by it.

[RickM]

What brand/type do you use, Jim?

[silverc4s]

Ranchers and farmers here in Texas use the cold galvanize spray on outdoor metalwork with much success. I have used it in the past, especially good on heat exchangers...;}

[Jim Garfield]

Originally posted by RickM
What brand/type do you use, Jim?

Rick, the last time I bought a can was 10 years ago....I'll look tomorrow and see if I can find what the brand is.

[kycarguy 935]

I use CRC Zinc-It part #18412 and it works great. I use it all the time. Its about $7.95 for a 13 oz. can at my local nut and bolt house. I'll have to check Lowe's and Home Depot next time im there for it.

[Willem Fick]

Hot dip galvanizing will warp sheetmetal.

Take the parts off, have them sandblasted by someone who has experience in body panels (sandblasting can warp these too!), and then have the parts electroplated with zink.

This is a cold process, but as good as hot dipping imho. You can probably do this at home, but why bother - it's really cheap to have professionally done. Did my bumpers, bumper brackets, anti-roll bar, hood, fenders, replacement sheetmetal, and various other bits for less than $50.

It's a nice idea to have any parts that won't be painted, passivated after electroplating (turns them yellow, not unlike cadmium plating).

Electro-plated zink, leaves a slightly rough surface, which I found to be excellent for primer adhesion after very light wet-sanding with 600 grit.

Be mindfull to chemically clean any plated surfaces properly before applying paint though - I used a phosforic acid based cleaner for this that I got from my paintshop.

Cheers!

Willem Fick

[Jim Smolka]

Rick,

What you might have seen in the video is what they do to BMW's at the plant in SC. It is a tuff primer called "E-Coat". Comes out as a dull light olive green color. Really tuff stuff. Wish I knew more of the process.

[RickM]

Could be Jim, I saw the clip many years ago. Im curious as to what Mike comes up with.

[billyboy]

I have hot dip galvanized many large steel pieces and without a doubt, you could not hot dip a porsche due to the thickness(thinness) of the steel. There would be severe warpage and all the threaded holes would be ruined. LPS makes a good spray cold galvanize as does Krylon. As with all paint and galvanizing(hot dip) , surface prep is paramount. For HD galvanizeing, the metal is first degreased, sandblasted, then pickled in hot alkaline bath prior to dipping in molten zinc. For spray cold galvanizing, sand blasting is the best way to prep the metal and then heat it to drive out the latent moisture if possible.Many 2 part epoxys for marine use are very effective at rust control with proper metal prep.

[Wrecked944]

I just got my Eastwood catalog last night and they have a zinc plating system for sale...

http://www.eastwoodco.com/shopping/product/detailmain.jsp?itemID=134&itemType=PRODUCT&RS=1&keyword=zinc

It seems to be a brush on system. I've used a similar system to do gold electroplating and it worked like a charm. No idea if the zinc system works as well.

And not to hijack this thread but...I recall we once discussed auto-darkening welding lenses for welding and I said I'd try to find an example somewhere. Well, it turns our host sells them...

http://www.pelicanparts.com/catalog/shopcart/TOOL/POR_TOOL_CAT348_pg2.htm