allowable metals

VictorE · 12/16/2009, 11:30 AM

Working on my plumbing construction and considering the use of a quick connect fitting which will allow me to drain the plumbing system quickly and cleanly without. The fittings I'm thinking of using are typically either zinc plated or brass.

What metals are considered hazardous to have in a tank both from a dissolved metals perspective as well as corrosiveness of the fitting itself?

uncleof6 · 12/16/2009, 11:45 AM

Titanium is about the only "safe" metal to use in saltwater. Brass is copper and zinc, it is not saltwater resistant in any way. You will have both copper and zinc in the system. Zinc is a trace element in seawater,(as is copper) but, but like copper, putting zinc fittings in the system would raise the zinc level to potentially harmful levels. Zinc dissolves so readily, that it is used as a sacrificial anode to protect other metals from corrosion (cathodic protection)

Jim

walkthedog · 12/16/2009, 11:48 AM

Almost all metal will rust when it is used in a saltwater set up. DON'T USE THE BRASS. Copper is one of the metals in that alloy. Even stainless steel is going to rust quickly. If the metal is not going to be submerged in water then it will be ok to use and just replace if when it rust. Again, don't use anything that contains copper. You can buy plastic clips / clamps that will work ok in most applications. I would suggest you look into them. Metal and salt just don't mix well together

uncleof6 · 12/16/2009, 11:54 AM

*** did it again....

Juruense · 12/16/2009, 12:18 PM

Super high quality stainless can be used in areas adjacent to salt water but not ideal to use it submerged.

Titanium can be used submerged.

That's it there are no other safe metals.

TP123 · 12/16/2009, 02:50 PM

Quote:

Originally Posted by Juruense

Super high quality stainless can be used in areas adjacent to salt water but not ideal to use it submerged.

Titanium can be used submerged.

That's it there are no other safe metals.

He's right. Just about every metal out there will corrode in saltwater. Even stainless steel can corrode.

The ones that won't corrode are too expensive for most of us. Even titanium is generally too expensive to be practical.

Randy Holmes-Farley · 12/16/2009, 03:09 PM

I have some 316 stainless float switch arms that have been in my system for 14 years and they are just fine, but definitely brass and zinc plated steel are huge no no's.

shereth · 12/16/2009, 04:36 PM

Quote:

Originally Posted by Randy Holmes-Farley

I have some 316 stainless float switch arms that have been in my system for 14 years and they are just fine, but definitely brass and zinc plated steel are huge no no's.

+1 on this one; 316 stainless is pretty corrosion resistant and will stand up pretty well to saltwater applications. If you do go stainless, just make sure it is the 316 alloy and not the more common 304 alloy or you'll be rusting before you know it.

champ128 · 12/16/2009, 04:36 PM

only the best stainless will not rust. It is very hard to find theese days.

12/16/2009, 11:30 AM	#1
VictorE Registered Member Join Date: Jun 2007 Posts: 284	allowable metals Working on my plumbing construction and considering the use of a quick connect fitting which will allow me to drain the plumbing system quickly and cleanly without. The fittings I'm thinking of using are typically either zinc plated or brass. What metals are considered hazardous to have in a tank both from a dissolved metals perspective as well as corrosiveness of the fitting itself?

12/16/2009, 11:45 AM	#2
uncleof6 Registered Member Join Date: Jul 2004 Location: AWOL Posts: 12,013	Titanium is about the only "safe" metal to use in saltwater. Brass is copper and zinc, it is not saltwater resistant in any way. You will have both copper and zinc in the system. Zinc is a trace element in seawater,(as is copper) but, but like copper, putting zinc fittings in the system would raise the zinc level to potentially harmful levels. Zinc dissolves so readily, that it is used as a sacrificial anode to protect other metals from corrosion (cathodic protection) Jim __________________ "Things should be made as simple as possible, but not simpler." (oft attributed to Einstein; most likely paraphrasing by Roger Sessions; compactly articulates the principle of Occam's Razor) Current Tank Info: 325 6' wide Reef

12/16/2009, 11:54 AM	#4
uncleof6 Registered Member Join Date: Jul 2004 Location: AWOL Posts: 12,013	*** did it again.... __________________ "Things should be made as simple as possible, but not simpler." (oft attributed to Einstein; most likely paraphrasing by Roger Sessions; compactly articulates the principle of Occam's Razor) Current Tank Info: 325 6' wide Reef

12/16/2009, 03:09 PM	#7
Randy Holmes-Farley Reef Chemist Join Date: Apr 2001 Location: Arlington, Massachusetts Posts: 86,233	I have some 316 stainless float switch arms that have been in my system for 14 years and they are just fine, but definitely brass and zinc plated steel are huge no no's. __________________ Randy Holmes-Farley Current Tank Info: 120 mixed reef

12/16/2009, 11:48 AM	#3
walkthedog Registered Member Join Date: Dec 2008 Location: Charlotte,NC Posts: 370	Almost all metal will rust when it is used in a saltwater set up. DON'T USE THE BRASS. Copper is one of the metals in that alloy. Even stainless steel is going to rust quickly. If the metal is not going to be submerged in water then it will be ok to use and just replace if when it rust. Again, don't use anything that contains copper. You can buy plastic clips / clamps that will work ok in most applications. I would suggest you look into them. Metal and salt just don't mix well together

12/16/2009, 12:18 PM	#5
Juruense Registered Member Join Date: Nov 2008 Location: Fort Wayne, IN Posts: 1,138	Super high quality stainless can be used in areas adjacent to salt water but not ideal to use it submerged. Titanium can be used submerged. That's it there are no other safe metals.

12/16/2009, 04:36 PM	#9
champ128 Registered Member Join Date: Oct 2007 Location: bloomfield, MI Posts: 65	only the best stainless will not rust. It is very hard to find theese days.