I received these photos from Michael Freiert of New Studio Architecture – the door leads to a hot tub patio from an indoor pool on Lake Superior.
Any idea what is corroding or oxidizing inside of this door – and to this extent?? I’ve never seen anything like it!
What’s the solution? WWYD?
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Probably the chlorine from the pool.
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The pool in the background is suspect (chlorine).
Looks like galvanic action. Steel and aluminum are not compatible and when come into contact the iron in the steel will oxidize. The zinc can be a barrier but that may have been eroded or corroded by the chlorine from the pool?
I had a customer that has an inside heated salt water pool , he can not keep the door hardware from rusting and corroding , it’s a losing battle .
It looks like pitting corrosion caused by chlorine. See detail explanation here https://www.libertypackaging.com/blog/bid/104234/chlorine-pitting-corrosion-and-intercept
I see corrosion like that all the time with aluminum store fronts. typically at the bottom of the frame where Ice Melt collects.
This looks like the same corrosion. I would say it is caused by what ever chemicals are used in the pool or hot tub. They off gas quite a lot.
No doubt – the pool chemicals. I would say they must be bringing them thru that door, but I see it goes all the way around the whole frame. I see a large amount of it on the windows. Are they jumping and getting the pool water on it?
Must be a very high humidity level and high chlorine content suspended in the air on the pool side causing the chemical reaction between the chassis bracket and the aluminum door surface which is apparently so potent that it is going through the prep holes in the door and bulging out the dummy trim on the exterior side. I don’t think the “gunk” is dense enough to distort the dummy trim, especially since the trim is mounted with thru-bolts. I would bet that the trim was mangled by human cause. It almost looks like someone got a can of whipped cream and dispensed it in the door and it is escaping through whatever holes it can find. The touch pad of the exit device just looks like it needs a good cleaning. Yuk!
If someone in this forum has a little chemical engineering background, they could explain it scientifically and better than my simple attempt.
It’s Chlorine. I see a pool in the background of one of the pictures.
GALVANIC CORROSION
alum door , stainless steel / brass hardware
dissimilar metals with the chlorine from the pool and chemicals from the hot tub.
toxic stew
This!
Galvanic corrosion?
Chlorine fumes would be my guess.
It’s from the chlorine and other pool chemicals that have evaporated in the air. I’ve seen this a lot, especially around indoor pools.
When I was in the commercial drywall business years ago we had to repair numerous acoustic drop ceilings in indoor pool areas. Contractors would use standard, galv., or stainless steel ceiling wires that would corrode to the point that the ceilings would fall down. At the time the only ceiling wire that would work was a special nickel-copper alloy wire.
My best guess would be chlorine from the pool, spa or both, reacting with the dissimilar metals in the hardware. The door appears to be aluminum, most likely coated with a Kynar paint. Replace the ED trim with a Bronze based product and use bronze fasteners. Chlorine is an extremely reactive element and a strong oxidizing agent. Unfortunately a lot of parts inside the exit device are steel, compounding the issue.
I’m not so sure it’s corrosion. The exterior photo looks like someone tried to seal all of the loose mounting with brick mortar. It looks just like the mortar substance in the far lower left of the photo.
The interior photo seems to be the same mortar around the head of the device..
Those are water marks on the glass, and this door is very near a diving board as you can see from the reflection in the glass.
My best guess is that someone realized that water was getting inside the structure of the door and did their best to seal it up.
I have seen similar conditions, but it was due to ice melt chemicals. When we removed a bottom pivot hinge. The part that went inside the frame had turned into a pillar of salt.
My guess would be the chemicals they are using in the hot tube combined with the high humidity.
If I had to guess I would say it is the catalytic action that happens with aluminum and steel. You see this kind of corrosion on swimming pools made of steel or aluminum when the incorrect fasteners have been used.
Also it could be likely that the spa uses a hydrogen peroxide product to disinfect the spa.
Although I am in the door and hardware industry my family has been in the pool and spa business for over 50yrears.
Not a chemist just an opinion.
Robert
http://www.infiitedoors.net
The corrosion must be from the high humidity/chlorine/heat in the pool room. Years ago we had a similar situation in a water treatment plant. The solution we used was a solid fiberglass door and a stainless steel exit device with stainless steel fasteners.
I remember seeing this type of corrosion near the ocean, actually had some von duprin replaced.
Hey Lori. I’ll bet you anything it’s the chlorine that atomizes into the surrounding atmosphere. I’ve seen that exact kind of corrosion on the pool hardware at my local gym. The photos are a pretty extreme example but if it’s been that way for years it would continue to accumulate. A lot of times the chemicals used in the pool are also used to clean the doors which makes it even worse.
Is it possible that some combination of chlorine-laden vapor (from either the pool or the hot tub) is attacking the aluminum where it is uncoated (at hardware cutouts)?
Is this a sulfur pool? Only thing I can think of that could build up like this.
The warm inside air will migrate towards the colder outside carrying chlorine laden water vapor with it and condensing on the colder interior of the exterior skin. Just my theory.
This is a very good question. I also encountered such a problem. To extend the life of the front door, it is important to monitor the condition of the hardware and, first of all, this applies to the locking mechanism, to ensure its smooth operation it is necessary to regularly lubricate the lock. At first glance, this is a simple procedure, but it has a number of important nuances, if you do not follow these recommendations, you may have to completely change the lock due to its breakdown over time. Lubrication of door hardware is the responsibility of each owner, it is necessary to carry out such work regularly to avoid problems and breakdowns of a different plan. This is especially true of the castle, since it is this detail that plays a huge role in ensuring the safety of the home. Good luck.
chlorine corrosion
My bet is the chlorine/chemicals for the hot tub are mixed incorrectly. My mother in law tried to do the chemicals in her hot tub herself. Did not turn out well.
I have experienced this many times in pool or hot tub enclosures . It is a chemical reaction from to high chlorine and bromine in the water as it evaporates its particles go everywhere. That’s why chemical ,sewage treatment facilities. Oil rigs etc usually spec marine grade stainless steel hardware .
There is a special treatment that can be applied at the factory when using Aluminum doors and frames . You may have to inquire about it . But the chemical reaction between aluminum and steel with salt water chlorine laced fresh water creates an catalytic conversion that will essentially eat through anything. . Dissimilar metals also react when you add water salt and other air borne chemicals
Many times indoor pools have quite high clorine levels. I’ve seen where the structural steel and rook deck above the locker rooms adjacent to an indoor pools were corroded to the point where they had to be replaced. With the condensation around the door opening, I could see where hardware selected for a high corrosion environment would be a good idea.
I see the pool in the background. My first thought was galvanic reaction. So I asked Google. Here’s what I found:
Can chlorine corrode stainless steel?
As a dry gas it does not tend to be aggressive towards stainless steels, but as either a damp gas or dissolved in water it can be a corrosion hazard. Chlorine readily forms chlorides when in contact with gases such as methane, hydrogen sulphide and ammonia. Hydrochloric acid (HCl) can also be formed by these reactions.
How does aluminum react with chlorine?
“Aluminum and chlorine do not react rapidly at room temperature, but if the aluminum is heated, the reaction is vigorous. The product is aluminum chloride, a white powder that fumes in air, reacting with water to form HCl gas and aluminum oxide.”Apr 17, 2011
Interior AC set high enough to continually produce condensation on the cool interior metal parts in the already humid exterior environment next to the pool.
I was hoping to see some comments on this. I know aluminum and stainless can create a corrosive reaction but I’ve never seen it to this degree. I’m guessing the airborne chemicals from the pool are playing a significant role in the corrosion process.
I did a quick search online and found this in a Welding Design and Fabrication blog:
“Yes, aluminum and stainless steel can and do corrode when put together. The two differing metals set up a galvanic couple (aka a small battery) and corrode. Add in some moisture and the reaction happens faster.”
If you ever left batteries inside a flashlight for too long and then opened it, the corrosion is very similar to these pictures. Hence the “small battery” comment from the blog. The added moisture with the pool chemicals must be exacerbating the issue.
Are they any chemists following this that can chime in?
It’s my fault! I’m just publishing them now! It’s been a crazy week.
– Lori
Here’s another article I found online:
https://www.bssa.org.uk/topics.php?article=89
This article goes on to explain that the moisture plays a vital role in the corrosion process. Salt air, such as that found around salt-water pools, would be the perfect recipe for the corrosion seen in these pictures.
This article states that using stainless fasteners to secure aluminum plates together would pose little risk but using aluminum rivets to hold stainless material together would not be wise decision. I don’t understand why that would be the case. Again, need a chemist to help explain this in layman’s terms.
Back in the mid 1990’s I did some G.C. work at water and waste-water treatment plants.
The head pipe fitter for our company (schooled 30 years in the field) told me that stainless steel was a poor choice for use in a chlorine environment. This is a guy who regularly cut and welded 1/4″ thick stainless plate, so I figured he knew the material. Most people (specifiers and architects included) tend to think of stainless as non-reactive, and for the most part it is. Still, every time I see stainless steel specified near a pool or spa, I think of him.
As with others above, I’ll suggest galvanic reaction at aluminum/stainless interface, worsened by chlorine present in the air and splashing. Still, for a case as bad as shown here, a chemist’s input would likely shed light on the cause.
So the big question is… what should have been done instead? Brass hardware? No one actually seems to have a solution to the pool chlorine issue.
So should it have been fiberglass doors? Hot-dip galvanized painted HM frames?
I’ve seen this before perhaps to a much greater degree.
A company I previously worked for manufactured & installed aluminum structures … a lot of them were encompassing aquatic facilities.
Initially we thought evident corrosion effects were due to the chlorine used in the pool.
But after covertly investigating the matter we witnessed maintenance people (after hours) utilizing cleaning agents (to blast the scum off the pools concrete deck both inside & outside). I had asked them previously what we used and they said “just water”.
The effects were so bad the resultant chemical reaction actually “ate through” 75% of the .100 thickness (in some ares) of the aluminum columns / mullions at the concrete junction. In some cases the bituminous coating we applied (to the top of concrete) was also compromised even though we utilized a “base shoe”.
I “borrowed” a sticker from the cleaning agent drum and a chemical engineer advised of the highly corrosive reaction this would potentially cause when in contact with aluminum.
Things aren’t always what they seem.
Corrosion can be nasty and rather quick.
I was called to a beachfront house as the Ilco pushbutton locks on their beach gates were not working.
The aluminum gates were literally at the (Salt water) tide line and in the couple of years that the locks had been installed their zinc alloy casings had turned to moosh (Technical term) and the combination chambers inside were heavily rusted. Being double sided locksets the replacement price amounted to a couple of grand but the owners were way too wealthy for common sense and said “Just replace them and replace the locks in the garden just in case”. A good payday for me, but I really hated the waste.
I also had issues with very expensive solid brass locksets tarnishing on a beachfront house. Are you close to the water? The owner replied, “We have to wash the salt residue off the windows every week.” She had to live with the tarnishing. This was before the days of “Lifetime” finishes but I would think even they would have had a tough time coping.
Your question: “what is corroding or oxidizing”. The answer: The aluminum door stile.
Although you did not ask the cause or reason, like many responders, I suspect chlorine (exacerbated by dissimilar metals).
The volume is not surprising which, according to AFSA, can be “…+/- 20 times the volume…”.