US Divers steel tank restoration

[Chez7222]

This project was a risk but with some good advice from Paladin. Here's the quick of it.

http://i1288.photobucket.com/albums...3D483D9-2017-000001881C3458C0_zpsd85a54e7.jpg

Built a rig to hold the tank for stripping and painting.

http://i1288.photobucket.com/albums...9575E46C-399-0000002D4CA61EC1_zps102b7f60.jpg

http://i1288.photobucket.com/albums...A3A55983-399-0000002D46E8FEDA_zpsda389546.jpg

There was a stubborn epoxy underneath the paint; had to get my son's fresh arms involved.

http://i1288.photobucket.com/albums...907821CE-399-0000002D3E7150F1_zpsdea68c07.jpg

Ready for first coat.

http://i1288.photobucket.com/albums...2DB81CD1-399-0000002D2F61D4E7_zps45ddc234.jpg

Tank coated with two cans of Rust-o-leum cold galvanized paint. Let sit for 48 hrs at the minimum for decent curing.

http://i1288.photobucket.com/albums...E0581BD2-399-0000002D282714CE_zpsd6be64d3.jpg

A few coats of metallic top coat and this is the result.


http://i1288.photobucket.com/albums...709BEEB3-411-0000006CD860D376_zps49e5d728.jpg

Thanks again for the help Paladin

 

[Bellaco]

That looks GREAT!

 

[Paladin]

Nice job, man!

 

[Mikeguyver]

Fantastic! Did the tank have the USD vinyl coating in it? How about the inside liner? I have two USD steel tanks that I want to restore but I have to get past those challenges first. Mike

 

[Bellaco]

Is it at all harmful to media blast the outside of these tanks with something like baking soda to remove the old finish?

 

[rx7diver]

Bellaco,

A few years ago, one of my three LP OMS (Faber) 46 cylinders developed the dreaded paint blisters at the bootline. I chemical-stripped the cylinder (like Chez did above, except using a wood scraper) twice, but remained dissatisfied by the paint remnants that remained. I asked the teacher at the local vo-tech school to sandblast the tank. He said sand would be too abrasive, but recommended, instead, using some type of "beads" or "chips" he uses for this type of thing (especially for refinishing farm equipment). He had his students do the job. The tank was returned immaculate! I had intended to have the cylinder hot-dip galvanized before having it re-hydored, and so, for the "meantime," painted it with the Rustoleum Chez used above.

(BTW, I haven't completed the job; the tank has remained the way I left it about a dozen or so years ago.)

Safe Diving,

rx7diver

P.S. These OMS 46's were never originally hot-dip galvanized, so I didn't have the same concerns as Chez with preserving the original hot-dip galvanize surface.

 

[Chez7222]

Personally I would not use a media blaster due to wanting to save as much of the original galvanizing process that was done at the factory as possible. We have a sand blaster at the hangar where I work that I did not use for that same reason. In my opinion, use the right stripper for the job. No need to use an industrial grade stripper for a galvanized tank that has been top coated with a rattle can like this one was. Luckily it was easy to figure out since the paint was flaking off exposing the galvanized exterior.. This tank was covered with regular paint so a top end household paint stripper was used. If you have an epoxy or other factory based paint application that is normally used on scuba tanks, I would remove existing corrosion, keeping as much of the original paint and primer as possible with a high grit sandpaper. Then I would apply a like color top coat, curing time is the key! This process requires patience, in the end everything corrodes but like my old Gunny used to say, "Pretty Don't Kill"

@MikeGuyver - I could not see the vinyl coating in the interior when I did the Visual. I have another tank with a factory date of 1963 that I bought from a guy that had a full charge of air from 1990. When we discharge it and looked inside, it was entirely white, mint, cherry. Passed hydro with no problems. With your tanks I would get them hydro'd at the same time and asked your LDS is your could refinish them first then bring them back so they can apply the Visual Stamp.

 

[Mikeguyver]

I had one of the tanks hydro-ed at a regular cylinder testing place and it had no problems. He did say that there was some light surface rust inside and it would need to be "whipped". I then took it and a similar tank (my future twins) to the place that my LDS has their tanks tested. He said that the one that I had previously hydro-ed would need to have the inside coating removed (by tumble or other means) before it would be usable (pitting/bubbles inside). He also said that the vinyl coating (I think USD called it their "tuff-coat) would need to be removed. My LDS told him that he wouldn't fill it because of it's age but the hydro-guy felt confident that the LDS would fill it if he told him that it was fine. The other tank was looked at and he said that it looked almost brand new inside. He then said again that I would need to remove the inner liner/coating and the outer coating down to the galvanized tank before it could be hydro-ed, passed visual and then filled/used. I have read posts on the VDH site about others successfully removing the liner and also how people scraped the vinyl off their tanks. I have to decide what I want to do. Any suggestions from the viewers would be appreciated.

 

[simonbeans]

There has been much discussion about the linings. Just because the tank has one, that not necessarily means it has to be removed. More like what is its condition? Also, if the tank has a vinyl coating, unless it is cut or you see blisters, etc., I don't know why you want to remove it. If you remove it and it is galvanized underneath, why do you want to paint it? Paint is pretty until you use the tank. It ALWAYS gets nicked, etc., and you will be repainting again and again. Galvanizing is the finish of choice. Not many painted or vinyl coated tanks at dive resorts. Granted most use Al tanks, but they are just the plain natural Al color as they get beat badly.

Seems most of my vintage buddies have all galvanized tanks except a couple of Sportsways Orange vinyl (I like orange).

 

[Mikeguyver]

Should I just forget about restoring the two tanks and look for another pair of steel tanks? I have a set of used "Peanut King" bands that I want to use so I'm locked into something about 6.9" in diameter. Does that substantially narrow my choices? I see some tanks that are 7" in diameter; will they work with 6.9" bands? I appreciate the advice/input. Mike