galvanizing gas tank

[Domenic T.]

A while back I thought my tank was cad plated and found that it was a form of galvanizing. (Terne coated) is as close as I can can remember without my shop notes.
I was just contacted by a company that does hot dipping. He said he didn't do tanks because of a venting size problem, I explained the hole sizes the vette tank has and he said that that was possible. He also did not recognize terne coating to be a form of galvanizing.
I tried all the good advice I got from my post and it just didn't do it, I wanted the new look.
How far off would galvanizing be?

DOM

[Dick W.]

Re: galvanizing gas tank

Be quite a bit difference in appearance. Terning leaves a very bright smooth finish, galvanizing is quite a bit duller and has a somewhat rough finish

[Terry M.]

Re: galvanizing gas tank

Look up terne coating on the Internet.

http://en.wikipedia.org/wiki/Terne

I believe, without disrespect to Joe Lucia's opinion, that the tank material is galvanized sheet steel. The galvanizing being applied by electrodeposition on the sheet before it is formed into the tank halves. Perhaps we are using different terms for the same thing, but since I have restored a home that is over 100 years old, I am thinking of terne coating as a lead coating.

I will tell you that hot dip galvanizing (think the old style metal garbage cans) does not look at all like electroplated sheet stock. All that said, if you decide to get your tank hot dipped it will in all likelihood last longer then you and your children, especially if they do the inside as well as the outside.

One Caution -- if your tank is from a 1969 and up Corvette there will be a vent valve in the top that is NOT removable. I am pretty confident hot dipping the tank will destroy the function of that valve.

[John H.]

Re: galvanizing gas tank

The primary component in galvanizing is zinc; terne-coating is primarily lead and tin. Both processes were done to the raw coil/strip stock, before the tank halves were stamped. Corvette tanks were made from terne-coated steel, not galvanized.

[Terry M.]

Re: galvanizing gas tank

Then duplicating the finish after the tank has been formed and assembled would be a daunting task. I don't believe hot dip galvanizing (a dip into molten zinc) will cut it in terms of a judged finish. Of course if judging isn't a concern, that is a horse of a different color.

[Chuck S.]

Re: galvanizing gas tank

From observing hot-dipped galvanized structural steel, I would say a hot dip galvanized fuel tank is unlikely to have an aesthetically pleasing appearance...the words "very coarse" come to mind.

A kind of slag forms on the top of hot molten zinc. Depending on how carefully the zinc has been "skimmed" just prior to dipping, and how the part enters and leaves the zinc, you could end up with ugly surface defects if "slag" sticks to the part.

I don't know the quoted price for hot dip galvanizing a fuel tank, but probably for the same or less money, and a lot less trouble, you can have a reproduction tank that looks just like the old one (there may be some nearly invisible differences in the welded seams) delivered to your door.

If the old one can't be cleaned up and restored to an acceptable appearance, without leaks, the repro is a no-brainer.

[Terry M.]

Re: galvanizing gas tank

My point about the appearance of hot-dipped is exactly the one you make Chuck. Electric utilities use a lot of hot-dipped galvanized parts -- think of the towers that look like Erecter sets dotting the countryside. The substations with outdoor equipment are full of hot-dipped structural steel as well and I have spent a lifetime around that stuff. It will NEVER look like a Corvette gas tank, but it does last and last -- which is why I will have the frame of the 1967 Chevelle I am resto-modding hot-dipped. I will never be able to pass that car off as original anything though, so longevity rules my decision.