Even Older Twin 38s

[SurfLung]

Need Finishing Ideas...
- I tried to remove the yellow paint with acetone and found out it wasn't the yellow paint that was faded... It was silver paint on top of the yellow. And, the yellow doesn't come off with acetone... At least not without a bunch rubbing with steel wool... Doesn't seem like the acetone is touching it.
- Well I wanted to sand blast a couple of spots where the corrosion was bubbling. That took those spots down past any galvanizing to the bare metal.
- So then I tried sand blasting off the yellow paint. Holy cow it is almost as hard to blast off as plating.
- So then I got to thinking, "Why remove such tough protective coatings?" So I stopped to think on it more before going further. Due to the bare patches, I'll need to apply something for protection.
- My goal is silver gray tanks and bands like Sea Hunt... I was hoping for the knock-around toughness of galvanized so I wouldn't worry about scratching them. Any suggestings?

[gj1963]

Have you tried lye based oven cleaner? Will usually remove softer paints and won't hurt other stuff, just don't leave it on too long. Be sure the threads are well capped off.

[crimediver]

I suspect the rust you found under the bands are from the bands themselves. I have put a thin layer of vinyl under my bands and it prevents rus and galvanic corrosion if they are disimilar metals.

[captain]

Aircraft paint remover will remove almost any type paint and will not harm galvanize.

[SurfLung]

- Thank you. I've been re-thinking the wisdom of removing such durable finish. What if I just patch and refinish the entire tanks with that galvanize stuff I've seen mentioned here? ZRC Galvalite? Is that the stuff. Does that need to go over old galvanize and bare metal? Can it go over paint?
- I saw some stuff on Amazon for $55 a quart... Yikes!
UPDATE
- I ordered a quart of ZRC Galvilite today...

- I'm going to do the tanks, bushings, and harness bands in this stuff.

[captain]

Galvilite is THE stuff for steel tanks but it is best applied to bare or galvanized metal. Using it over another type coating negates most of it benefits. You could us it to touch up areas bare of any paint. Although it can be top coated it is not necessary other than for appearance and also tends to negate some of it self healing properties.

[SurfLung]

Galvilite is THE stuff for steel tanks but it is best applied to bare or galvanized metal. Using it over another type coating negates most of it benefits...

- Good to know. All the silver paint came off easy. It's just the yellow that's so tough. I'd like these tanks to look uniform so I think I'll finish sand blasting the yellow paint off and give them an all over finish with the Galvalite.

[swimjim]

I've used a stiff sharpened putty knife and a little MEK to remove stubborn paint off scuba tanks in the past. It requires good ventilation and some elbow grease, but it gets the job done.

Jim

[captain]

Galvilite is THE stuff for steel tanks but it is best applied to bare or galvanized metal. Using it over another type coating negates most of it benefits...

- Good to know. All the silver paint came off easy. It's just the yellow that's so tough. I'd like these tanks to look uniform so I think I'll finish sand blasting the yellow paint off and give them an all over finish with the Galvalite.

Use a small foam roller and put on 3 coats 24 hours apart and let it cure for at least a week before use.

[SurfLung]

Liquid Metal...
Refinishing Old Tanks with Galvilite 95% Zinc Paint.

- (above) Tanks sand blasted and wiped with acetone. "Liquid Metal" Galvilite.

- (above) Galvilite wet and Galvilite dry. When wet, the Galvilite color is almost indistinguishable from the steel... You have to keep a watch to make sure you are coating the steel completely and didn't miss any spots. The dry finish is very even and I can see why touch-ups will be invisible. The "dry" photo almost looks white but it is a very light, flat silver/gray. From a Mike Nelson Sea Hunt UDT perspective... Very "Navy" looking IMHO.
- "Liquid Metal"... Reading up on the specs of Galvilite I learned a few things. First, Galvanizing anything coats it with Zinc. The purpose of it is so that the Galvanic Reaction that causes corrosion will happen to the Zinc rather than the steel. I noticed during sand blasting that when I took off the corroded galvanized finish, the steel was almost smooth and untouched beneath. Galvilite works exactly the same.
- Galvilite is some Real Stuff... It's 95% zinc metal. The quart can I bought is heavy. Open the can and you see liquid metal floating in the un-stirred paint. I used a stirring spinner and electric drill to mix and blend it well... And it needed it as a lot had settled in the bottom of the can. It never gets to looking even-colored like paint. The picture above shows it after spin stirring it for quite a long time.
- Expensive? At about $50 a quart, Galvilite is not cheap. But it goes pretty far. At the point this photo was taken, I had used about a quarter of the can to coat both tanks two coats, and the tank bands one coat. Compared to having a plater hot dip Galvanize, I expect the Galvilite used is cheap.
- The Real Expense... I've got a heck of a lot of physical time and work into this. And if I was paying someone for it, it wouldn't be worth doing. For example, I'm fortunate to have access to a sand blasting cabinet at work. Our blasting media is for surface prep before finishing custom rifles... So my blasting media is not very "aggressive". That probably added a lot of time to the sand blasting process. Also, the '60s black tank bands were coated in black vinyl. I had to soak them in acetone to get the vinyl off before sand blasting. A throw away tin foil turkey roasting pan was the only thing big enough to soak the bands in. They look beautiful now with the Galvilite coating!
- The Hard Part is Done. Now I've just got to sit tight and let the Galvilite cure for a few weeks...

[swimjim]

Nice work Eben. I cannot wait to see them in action!

Jim

[Robohips77]

Excellent job. Your description is exactly the process I use when doing tanks also. I have been very successful. My only complaint about using Galvalite is that once the can is opened and air has been trapped after use inside the can you will have some hardening and spoilage of the product..... so if anyone has any suggestions to save on the spoilage it would be appreciated. Good job on the tanks.

[captain]

It may help if you store the can upside down.

[8dust]

I cut tight-fitting circles of visqueen to cover ½-full cans of expensive but unfinished things. Sorta is like an artificial pre-cured "skin." The plastic has to be right at the inside diameter of the can or else air will get in around the edges. Also good to keep the inside of the can walls and top lip clean to avoid dried bits falling into your mix. There may be some materials which are incompatible with the plastic, but have used on glues, acrylic-based coatings, and joint compound with total success. I would think that anything that comes sold in plastic would be fine. As I'm guessing the galvalite is solvent based, so a circle of "baker's parchment" would be my other choice. I use that quite a bit in the shop as nothing sticks to it and it doesn’t melt like waxed paper. Available at most any grocery store. Either one costs nothing & works great... my favorite.

[antique diver]

On other types of paint I use "Saran Wrap" or equivalent to cover the paint surface down in the can. It can be a larger piece, and it is so flexible that I can smooth it out over the paint surface and up the inside walls of the cans. Works pretty good on keeping the paint from drying, and I suppose that would work with the Galvalite also.