Brown etching on stainless steel in pool house?

[pcm2a]

I have had a stainless steel fridge in the pool house for 9 months. I noticed today that is covered in brown spots. I scrubbed it off with vinegar but it seems that it has etched the surface! The only thing that has changed is a week ago I brought in a 25 pound bucket of calcium hardness. I used it all over a few days and the lid was kept on it.

Could that chemical have done this to the stainless steel?

 

[YippeeSkippy]

no, doubtful. My stainless fridge sure seems easy to ding though. I don't have any yellowing on that, but i do have dings. And my stainless stove has yellowing from the heat of cooking.

Try using a stainless polish on it, only swipe it on/off with the grain of the stainless.

Maddie

 

[JoyfulNoise]

CH increaser is calcium chloride, think of it as equivalent to table salt. If you were mixing the CH increaser in the pool room, I suppose it’s possible you could have gotten some fine powder around. It would act just like table salt and cause the pitting corrosion you are seeing.

You can certainly clean it off with vinegar but that’s not the best approach as the acidity will likely cause further corrosion. I would use a pH neutral cleaner like Evapo-Rust or something similar. You then need to polish and seal the surface with a steel cleaner. Since the pitting has compromised the passive oxide film, you’ll need to keep the surface sealed with a steel polish as that leaves behind a thin oil film.

 

[JamesW]

The most common reason for rusty stainless steel in a pool room is trichlor tab fumes or muriatic acid fumes.

 

[pcm2a]

The most common reason for rusty stainless steel in a pool room is trichlor tab fumes or muriatic acid fumes.

I bought a gallon of Muratic acid a couple days ago and poured some in. I did all the mixing outside, rinsed everything and only left a sealed jug in the pool house. I will move it to the garage.

 

[JamesW]

Storing muriatic acid in the garage = RUST

 

[pcm2a]

Storing muriatic acid in the garage = RUST

Thanks for the tip. I've put it in a washed out calcium hardness bucket behind the pool house. Nothing to rust now.

 

[JamesW]

If you have trichlor stored in the room, it can sometimes be a problem, as well.

Mostly if the tabs get moisture in the bucket or if the bucket is opened inside.

 

[pcm2a]

If you have trichlor stored in the room, it can sometimes be a problem, as well.

Mostly if the tabs get moisture in the bucket or if the bucket is opened inside.

I do have a bucket but it's always been in there and the tablets are individually sealed.

 

[JamesW]

Ok, just be aware that it could be an issue. Make sure to never open the bucket inside the room.

 

[pcm2a]

Ok, just be aware that it could be an issue. Make sure to never open the bucket inside the room.

It was always opened in the room. However it hasn't been opened in several months and this rust has popped up in the past week. Good to know to always take it outside.

 

[JoyfulNoise]

It was always opened in the room. However it hasn't been opened in several months and this rust has popped up in the past week. Good to know to always take it outside.

That'll do it! Doesn't matter if they're sealed. I had a sealed bucket of individually wrapped trichlor tabs in my garage for a month and it caused rust to form on a metal wire rack nearby. Those buckets emit chlorine vapors even when sealed. Chlorine vapors may not be detectable by smell but low concentrations over long periods of time will definitely rust anything steel nearby.

 

[JamesW]

The dust can also get airborne. Opening the sealed pouches can cause dust to get in the air.

 

[pcm2a]

The dust can also get airborne. Opening the sealed pouches can cause dust to get in the air.

Where do you store all the chemicals? Maybe in a van .... down by the river.

 

[JoyfulNoise]

Where do you store all the chemicals? Maybe in a van .... down by the river.

I loved those Chris Farley skits on SNL!!

I store chemicals outdoors away from anything I care about in a small Sun-cast deck box. I only use acid really so that’s all I have to store.

 

[JamesW]

You don't want to store chemicals in a van. They should be ok as long as they don't get wet and you only open them outside.

Keeping them in a box outside but out of the sun is best.

 

[pcm2a]

Is it only stainless steel that is so sensitive? I have two aluminum ladders that also live in the pool house that have taken no damage. There are also two doors that both have brushed nickel handles without damage. There is an old lamp in there that looks like stainless steel to me and it has similar damage to the fridge.

 

[MinerJason]

Is it only stainless steel that is so sensitive? I have two aluminum ladders that also live in the pool house that have taken no damage. There are also two doors that both have brushed nickel handles without damage. There is an old lamp in there that looks like stainless steel to me and it has similar damage to the fridge.

It's really steel (or more accurately iron) that's highly sensitive to corrosion from exposure to chlorine/chlorine fumes. Stainless steel is steel with chromium added to enhance the corrosion resistance. Other metals like molybdenum are sometimes added as well to increase acid resistance. The amount of chromium and other alloys varies widely between different stainless steels, so some are much more corrosion resistant than others. Your fridge and lamp are likely made of low alloy stainless steel.

 

[PoolGuy4Life]

Sodium Chloride is table salt.