Tank question

[fernandezh]

I have a Faber LP 95. The other day I took off the tank boot and noticed what looked like raised Braile bumps all along the surface of the tank where the boot had once been. The Hydro on the tank is only 1 year old and VIP less than 6 months. Should I be concerned about these little bumps along the surface of the tank?


Hector

[SCUBATOM]

Is the tank painted ??

[fernandezh]

Yes it is painted. It is painted white with the original paint from the Faber factory. The bumps look like perhaps it might be just the paint but I am not sure if the paint is becoming raised because of corrosion. What do you think?

[swimndive]

Hector, It happens to all Fabers when you leave the boots on. Sand the blisters down to bare metal and re-paint the damaged area. The bottom of the cylinder is plenty thick so you need not worry about this kind of surface damage. If you do nothing, eventually it could become a problem and it will continue to weep rust out of these blisters until you fix them. In the future, pull the boot off when you get home and wash and dry the cylinder before you put the boot back on for storage. Either that or ebay it and replace it with a galvanized pst.

[FredT]

Strip the tank and apply a couple coatings of ZRC.

Instant galvanized tanks! Also the end of maintainance worries for the life of the tank.

Bound to be a sand blaster on base somewhere! The original coating has failed. It'll be a lot better to replace it than patch it.

FT

[fernandezh]

FredT,

Thanks for the advice about the sandblaster. There is a motorpool here on base that sandblasts the paint off of M-1 Tanks to change their camoflage scheme. I'll give them a call. But what is ZRC? Where can I get it? does it need special equipment to apply?

[zds3488]

zrc=zirconium?

[FredT]

http://www.zrcworldwide.com/

Cold galv, 350 or Galvilite all have similar performance specs.

I prefer to apply by brush for a heavier coating. Read the info on surface prep!

FT

[SCUBATOM]

Hector, these guy's are right on the money, what you are seeing is surface corrosion and can easily be delt with as they have stated. Although I have been reading Spear Board for several months now, I just regestered a week ago. I live in Sav. Ga. and try to get down to Fla when I can. I'm looking FWD to meeting as many of the Spear Board family as I can. I would also like to let you know how much I respect and appreciate the job you soliders are doing for us and our counrty, God bless you all!

[deepstops]

Originally posted by FredT
http://www.zrcworldwide.com/

Cold galv, 350 or Galvilite all have similar performance specs.

I prefer to apply by brush for a heavier coating. Read the info on surface prep!

FT

Fred,

Have you ever used used POR 15?
http://www.por15.com/

[FredT]

ZRC works as an active anode. This self heals damaged areas for a more reliable coating subsea.

The specs on the POR-15 indicates it's "rock hard" leading me to believe it's a rather brittle coating since hardness and brittleness tend to travel in the same car.

Tanks have to "breathe" a bit when filled. Diameters of full tanks are actually a bit larger than empty ones. Since by the claims POR 15 has to have an intimate bond with the tank to work any chips or holidays would be a bad thing, potentially causing spot corrosion and tank failure. Depending on the ductility of the coating I'd suspect the formation of hairline or microscopic cracks during filling.

Small cracks and holidays are the reason epoxy and vinyl coated tanks have to be stripped before a visual or hydro.

I haven't used it so I don't _know_ if it'd work or not. I'd be interested to see how well it works on an old vinyl coated ungalvanized 72 after a dozen cycles to hydro pressure and submersion for a week or two in warm salt water. ( A quick way to stress screen the coating.) ANY holidays would require stripping for the annual inspection if the inspection is done correctly.

FT

[fernandezh]

Ok, so you are recommending to me something you haven't tried yourself? Have anybody here used zrc on their tanks?

[biggsy]

I think he is saying he has not used the PR 15 product.

biggsy

[FredT]

I've use ZRC on scuba tanks and hundreds of other things either regularly dipped in or living out their entire service life in seawater. I have NEVER had it fail to perform as specified, with most application exceeding specification by significant margins.


The suggested POR 15 alternate has statements in their product literature that makes me question wheither it will hold up as a pressure vessel coating. I have no proof one way or another if it will or won't work, but based entirely on ther published data before I recommend it I'd like to see the results of application specific testing.

FT

[fernandezh]

How do you apply ZRC? Do I need special equipment?

[FredT]

Originally posted by fernandezh
How do you apply ZRC? Do I need special equipment?

Uh.. Yes.
A paintbrush.

FT

[fernandezh]

Aww shit! I didn't know it was going to be THAT complicated :D

[bgbill]

I could not find the Zrc, so I used the spray cold galvanizing.

It is supposed to be the same product, but 1 spray can goes a long way and it was $6-$7 a can, a gallon was about $56, the spray can method worked real well for me.

Hector,

You Latino's know how to use spray can's don't you?:D :D

[fernandezh]

Spray Cans? Only if the ZRC comes in neon colors :D

[ROCK BOTTOM]

Here is something of interest to anyone refinishing there tanks with this stuff. Note: The woman never furnished me a solution for salt water.

Zz

----- Original Message -----
From: Lorraine DeWald
To: c.zelenka
Sent: Monday, January 12, 2004 8:17 AM
Subject: RE: scuba tanks


Thank you for your interest in ZRC's cold galvanizing compound - the brand recognized by Underwriters Laboratories as the equivalent protection against rust & rust creepage as hot-dip galvanizing and manufactured by us under the strict standards of our ISO-9001 certification to assure the highest quality consistently.

IMPORTANT: If you are going to use the aluminum scuba tanks in salt water, DO NOT use our product - or any product containing zinc! The reason is that in the presence of salt water, the elements of zinc & aluminum (zinc being the more sacrificial element on the sacrificial table - which you may recall if you ever took a chemistry class) reverse themselves. This means that in salt water, the aluminum and not the zinc would become the sacrificial element - just what you don't want!

For best results on a scuba tank being used in fresh water, please follow the attached Guide for Immersion Applications

You can use either of our original, 95% zinc in the dry film, single component (for use directly from the can) ZRC (medium gray, flat finish) or GALVILITE (the ZRC in the light gray, shiny finish designed to blend in with hot-dip galvanizing). The only difference is the color. I would suggest the liquid as opposed to the aerosol, even though they are both the same formula. The reason is that you are more likely to get the proper thickness - with fewer coats - than with the aerosols.

Coverage is 350 - 400 sq. ft. per gallon.

Although you do not need a topcoat (see our Guide to Topcoating), I'd think that since these tanks will be subject to abrasion, you'd want to apply a coat of aliphatic polyurethane which you can get from a good paint store.

Our products are non-hazardous for ground transportation, so they can be shipped by regular UPS Ground as well as common carrier, factory-direct or through DRAGO SUPPLY - Tel: (225) 673-6403 - E-mail: chebert@dragosupply.com

Please get back to me whenever we can be of further assistance to you in winning the battle against rust.

Lorraine DeWald

ZRC WORLDWIDE

Website: www.zrcworldwide.com

E-mail: info@zrcworldwide.com

Tel: 1 (800) 831-3275

[fernandezh]

I was thinking about doing this to my steel tank. Any potential problems with that?

[ROCK BOTTOM]

I am not certain. It would be best to check with the manufacturer on the proper application of this stuff. I have 16 tanks to refurbish and am probably going to have them blasted and leave them unfinished.

Zz

[FredT]

Originally posted by fernandezh
I was thinking about doing this to my steel tank. Any potential problems with that?

Not a bit, If using it on aluminum tanks the Zinc in the mix would need to be changed to Magnesium. The protective coating needs to be higher on the Galvanic Series than the base metal.

ZRC on bare steel is about as good as it gets.

FT