Summary for stainless steel jets rusting Discussion
Stainless steel jets rusting in a hot tub is usually explained as a corrosion problem, not a mystery defect. In the original question, Dean Clarke said the jet surrounds are SST304 and some are partly above the waterline, where they are rusting. Mark Baker explained that 304 stainless is corrosion resistant but not corrosion free; chloride salts can concentrate at the water/air interface, and the parts should have been passivated before installation. He suggested removing rust periodically with naval jelly and keeping pH in range. Marc Quaghebeur added that for marine-type exposure, electropolishing helps and 316 stainless is a better choice than 304. In a later question, Waynette Foster reported rusting rings and a rust-colored filter after a salt cleaning system was added. Ray Kremer cautioned that the exact cause could not be confirmed from the limited details, though the salt system was a likely contributor. Mike Davies said salt systems can rust metal objects and recommended ionization instead.
Q. I have a hot tub and the jets have stainless steel surrounds most of them submersed in water but some half in water half out .
the problem is they are rusting the stainless steel is of SST304!
Does anyone know why this may be idea, be grateful of any theories.
thanks.
Dean Clarke
consumer – Benfleet, Essex, england
2007
A. Hello Dean,
304 stainless is corrosion resistant, but not corrosion free. After all, the main constituent is iron. These jet rings should have been passivated by the manufacturer before installation in the tub. Chloride salts at the water / air level form on the steel, and it will rust. You could try to remove the rust with
naval jelly
⇦ on
eBay or
Amazon [affil link]
from time to time. Keeping the pH at proper levels helps too! Good Luck!
Mark Baker
Process Engineer – Syracuse, New York
2007
A. Dean,
For all marine-applications where you want to avoid stains and rust on stainless steel you should have your SS-parts electropolished.
For marine-applications SS 316 should be used – in combination with electropolishing.
So, you are suffering of two “faults” : insufficient material specification and insufficient finishing.
Marc Quaghebeur
– Brugge, Belgium
2007
Q. My husband put a salt cleaning system in our hot tub about 2 months ago. Now we are noticing that the silver colored rings around the jets are rusting. Also the filter has turned a rust color. What is causing this???
Please help! Thank you!
Waynette foster
– Big Lake Texas
February 6, 2015
A. Hi Waynette. Although people would like to help, there is so much uncertainty that it may not prove possible. The rings are “silver colored”, but we don’t know what they are made of or how they were finished. We don’t know what this salt cleaning system is. We don’t know that this cleaning that he did 2 months ago, rather than an overdose of bromide or something else at some other time, is what actually caused the rusting.
We can hope that the rings are stainless steel and that Mark’s advise helps though. Good luck.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com – Pine Beach, New Jersey
Need quick confidential answers? $25
Need project assistance? $100/hr.
February 2015
A. I would assume/hope that any metal parts on a hot tub are stainless steel.
I don’t know what “salt cleaning system” means either, but high levels of chloride are known to be damaging to stainless. (Pool water type levels of chlorination are also rough on stainless.)
Your best bet would be to remove the rust and repassivate using a citric acid based product.
adv.
Let us know if we can help.
Ray Kremer
Stellar Solutions, Inc.
McHenry, Illinois
February 10, 2015
A. I am not a fan of salt systems. They will do, as you’ve already discovered, what salt does and that is rust metal objects. We have salt system owners call with their hand rails and ladders, all stainless steel, rusting or rusted to the extent they can no longer use the ladder or handrail.
I’ve been using an Ionization system which uses silver and copper electrically charged to create silver and copper ions. This ions take care of the algae and bacteria better, yes Better, than chlorine.
If you’ve ever heard of cryptosystem, chlorine will not kill it. The ionization system will keep your water sanitized way better than chlorine.
Mike Davies
– Mobile, Alabama USA
April 8, 2016