Corrosion on the OSTC4

[Divert]

Hello I have been diving with my OSTC4 in salty water for only 26 hours total (25 dives) and It has been developing a weird corrosion over the OSTC letters

a few dives more

The corrosion does not seem to affect the side of the computer but also is bulged out. as can be seen on the following image

Of course, I wash my computer with fresh water after every dive.

Has anyone had the same problem?
What should I do?

Divert.

[geba]

Yes, I have the same problem. I removed the corrosion
and applayed aluminium grounding and coating, but it comes again. It seems to be only on the front of the battery compartment. The only i can imagin, is, that it is an electrolytic
corrosion as i see also on my boat. Maybe there is electric power running through the housing ?
The next thing i will try, ist to put a sacryfing anode on top
( zink or magnesium).
I also informed the company, they told me, that maybe some iron from the water comming on it, but it was not.
Saltwater and Aluminium is the problem.
The same things happened with scubapro, als they built a regulator housong with aluminium.

[geba]

Interesting is also, that the corrosion is around the letters over
the battery compartment. This also needs an investigation why it is so.

[jb2cool]

It’s the only place on the housing there is etching into the anodising. Could be related to the battery but could just be coincidence

[geba]

Saltwater which contains chloride are allways a big problem for aluminium and even stainless steel.Stainless steel by the way, is therfore not allowed in commercial marine.
For aluminium the best way is the so called hard coating,in military standard.
But anyway, sacrifying anodes are obligatory on boats and engines to protect aluminium.
Maybe, bronze or brass seems to be better to resist the attack of saltwater.
Most important is, to detect the corrosion, remove it and protect the surface with special coatings.
So, a housing, wich one can get from internet for the OSTC, ist probably not the best investment, because one cannot see, what is going on under the housing.

[Divert]

Somehow I have no issues at all with my aluminum camera housing. After 100's of dives with some scratches and dents, nothing, absolutely nothing, also, here in America, aluminum tanks are very common, some of them have a plain finish and no issues either.

Let's see what heinrichs Weikamp has to say about this.

Humberto.

[Walde]

The same once happened to my Orcatorch light on a liveaboard in Thailand, it started to "grow". It was type of light that you twist to turn it on/off and that white stuff was growing just at the edge where one parts goes inside other.
My plan was to do a reclamation but I lost the light on the last dive. Hope you find an answer what is causing this.

[geba]

The only cause i can think about, is the dammned electrolytic corrosion. This can happen, when materials other then Aluminium has contact to it. Even stainless steel. Most worse is Copper. The older Landrovers had exact the same problems, when steel from undercarriage had contact to Aluminium on top.
Why this happens ?
Because 2 materials and a litte bit of salt and humid produce an electric power to generate.
I think, in OSTC or in some torches not different metals are the cause, but electric power from the battery is running through the housing, mostly from the negative pole of battery.
And this makes the same bad storys.
I hope, to get answers from the company.
At time, there is no other way, as to remove the corrosion with spezial aluminium cleaner, paint it and keep it dry so often one can. After diving, wash it, clean it an dry it.
Dont use this plastic housing sold for protection, because underneath it will not dry completly.
Luckily the housing is thick enough for some small surface corrosion, but dont neglect it.

[heinrichsweikamp]

Hi,

Contact us directly, please and we have a look. You can't tell anything definitive from the pictures and the forum is not the right place for repair enquiries. info@heinrichsweikamp.com and we will be happy to help you.

Greetings,
Matthias

[geba]

You are completly right, but it is so, that aluminium corrosion affects not only Computers, but also torches, camera housings, boats and engines and even automobil parts made from aluminium and further more.
Every, sailor, diver, should be aware, that aluminium can corrode in marine condtions same as stainless steel also.
And in a marine forum this should be discussed.