14 replies to this topic

[JimG]

I have several patches of corrosion on a three year old aluminium housing. I am fastidious about washing my housing after use and giving it a long soak after weekends or trips away but all to no avail. I am on my fourth housing by this manufacturer and never before had such a problem so I think my regime of caring for my housing is well tried and tested. Here's the story:

I first noted corrosion when the housing was 2.5 yrs old but the spots were so tiny I couldn't make out what they were. Stupidly I then forgot about them for nine months and then suddenly realised they had expanded. A detailed look with a 10X magnifier confirmed the worst. This affects the housing back only and is at both ends where the hasps are screwed on. Strangely the front is perfect . Both front and back have anodes. The really worrying thing is that is creeping towards the o-ring groove and I assume once it gets in there, the housing is useless. At this point the housing was 3.25 years old and had done 281 dives. I took photos and reported it to the manufacturer. (see photo 1 below)

They wanted to know what strobes and accessories I used and then asked me to send it in for a diagnosis. Later they said they were going to “coat the affected areas to minimise their contact with sea water”. This was done at no cost and the main o-ring was replaced, also the rubber feet, hasps and anodes. I paid shipping at £170 approx.

When I got it back, they had done more than coating and had gouged out the corrosion and then coated the patches with black industrial strength enamel. I use the word “gouged” advisedly as, frankly, the job was crude and rough and the coating looked as though it had not been applied evenly with white areas clearly showing through the black enamel. Inexplicably, two small areas had not been touched at all. I was told they suspected the cause was water being trapped between the hasps and the housing. I responded that this was ridiculous - what about the other half of the housing and moreover, what about all other users of their housings from whom I have never heard a hint of such problems? I also complained about what they had done to the housing but to no avail and it was merely suggested I let them quote for a full strip down, re-anodise, re-coat and rebuild. See sample of work done below @ photo 2

I had no choice but to hope for the best as a few days after I got the housing back, I was to go to the Maldives. I am now back and after just 21 dives, it is very obvious the coating is breaking down generally and corrosion is erupting from one repaired area. See sample after 21 dives @ photo 3 below.

I have sent photos to the manufacturer and formally complained to the company and also personally to the CEO. There has been no response at all from which I assume they think I am being unreasonable.

Am I being unreasonable? Is it normal to expect such corrosion after this length of time?

I don't know what to do next - I had intended to upgrade my system later this year but will have to forget that as my housing is now unsellable so I need to prolong its life. Has anybody successfully repaired damage of this nature? Is there any material I can buy to stop the corrosion advancing?

All advice welcome

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[E_viking]

I can only wish you luck!

[Ronyx]

how big are these areas?

[downunder]

Corrosion will alway happen then you take something in salt water, most manufacturers have zinc anodes to corrode thereby protecting you housing does your have any zinc annodes ?

[jcclink]

I would check any possible contact areas between dissimilar metals. This includes fasteners, any housing/camera metal to metal contact points (camera mounting plate, housing control shafts/buttons, etc). Your photos seem to indicate somewhat large corrosion areas. Add a zinc if you don't have one. Apply a quality grade marine grease to all threads - something that remains as applied in sea water. Something is breaking down the protective anodize coating. Nee to find what this is.

[r4e]

Whatever protective layer there is on the aluminium, it will eventual be worn either chemically or mechanically. Mechanical wear is caused by the surfaces scraping against each other and even very minor dents at the very edges. Fine sand will accelerate this process. Depending how you handle and position the halves when opening and closing the housing, the points of first/last contact will have more wear on the protective coating. Surface wear and minor dents can also by caused during topside transport and storage. If you store the housing closed inside a pelican or similar case, (salty) dampness is likely to accumulate in the padding.

The O-ring will seal against the inner half of the groove. My guesstimate from your pictures is that with this advancement rate of the corrosion you might be lucky to use the housing for another 600 dives and/or 6 years(?). Of course, when the corrosion advances inside the O-ring groove, you'll have to be even more meticulous on cleaning and drying the groove as well, after every dive.

[E_viking]

Unfortunately, it seems to me that you really do not seem to have a choice! ( Other than running it down and buying another Housing then, assumingly not from the same Brand!)
A full re-anodise program, seems to be necessary. Would you get a completely "revitalised" backhalf then?
Out of Curiosity, how much would that actually be?
If you can talk the Manufacturer/Importer into doing it for free or not, that is another question.

I wish you good luck with this issue.

/Erik

[Timccr]

It might also be worth trying to find out if anyone else has had the same problem. I say this because there have been cases, but very few, of batches of ally tanks having had similar problems due to, I think, poor mixing of the alloy.

[loftus]

So this appears to be Aquatica - not good PR for them.

Edited by loftus, 13 February 2013 - 02:30 PM.

[JimG]

Thanks for the replies. I am pretty sure the galvanic action is coming from the stainless steel screws securing the hasps to the housing. The corrosion more or less lines up with their positions at either side of the housing back. But why just the back?. I have a friend who has a D3X housing slightly older than mine by the same maker and he says his is starting to go in roughly the same place. Not as bad as mine and he has treated his with Alocrom which is used industrially to repair damaged anodising. Too early to say if it is effective.
I have also been advised that if I can get the corrosion fully removed, there are various epoxies which would be very effective.
Various points raised above:

Ronyx
Photo 1 gives a good idea of size - that's the main o-ring just above the centre

Downunder & jcclink
Anodes from new on both halves of the housing

r4e
There was no wear or damage at all. It is actually quite hard to cause either where the corrosion is because the hasps project slightly higher than the back giving a measure of protection. If you were right about six years I would be delighted but this has advanced from very tiny marks to this size in about 10 months. Maybe a year if I'm lucky unless I find a good solution

Erik
I didn't price the full re-anodising. I was just told this would be expensive and would take a minimum of 90 days. I can't be without it that long and I don't think a full rebuild should be necessary on a £2500 piece of kit after such a short life. Anyway, after the crap repair job I wouldn't trust them to do it right.

[JimG]

Good news. With the general advice on this forum being that there is not much I could do to sort the corrosion, I asked the manufacturer if they would sell me a spare “blank” back, with me to switch the controls over. Unsurprisingly, their housings are made and kept as complete units so this was a no go but I am pleased to say they have offered to have the housing back – and for the whole unit not just the back where the problems are – to completely strip it down, sand blast, re-anodize, paint, re-assemble, test and return. All at no cost. That is a very generous solution and more than I ever expected so will get it done after a Red Sea trip in April.

[loftus]

Great to hear; way to go Aquatica.

[E_viking]

Congratulations.

 

That is what I call good Customer support!

[Ronyx]

That is some very excellent news indeed. You don't see that type of customer support too often.

[downunder]

Well done. Thats good customer support.