seacam/ikelite dissimilar metals corrosion problem - help?

[jong@seaotter.com 0]

Hey friendly forum,

 

I've been having a hell of a time keeping my bulkheads in my seacam housing from corroding away to nothing on the outside threads when I put ikelite sync cords on them (to drive DS-125s and SS200s). It's a dissimilar metal problem I'm sure.

 

Does anyone know if there exists a bulkhead for the seacam that is the same metal as the ikelite strobe connectors? Or if Ikelite makes a delrin or otherwise non-conductive plug end for their sync cords?

 

These bulkheads are a pain in the ass to replace, and not so cheap either.

 

All I need is for the threads to corrode away below the o-ring, and the whole housing could flood.

 

I've done some searches on the forums, but haven't seen anything relevant.

 

Thanks for any pointers!

[james 0]

Hi Jon,

 

I use Ikelite and Seacam. Ikelite makes a nikonos sync connector with a Delrin thread - you need to get these. It's a black material just like what Seacam uses for their macro ports.

 

HTH

James

[jong@seaotter.com 0]

Hi Jon,

 

I use Ikelite and Seacam. Ikelite makes a nikonos sync connector with a Delrin thread - you need to get these. It's a black material just like what Seacam uses for their macro ports.

 

HTH

James

 

Thanks for the reply James. So I'd need to replace my housing bulkheads with nikonos bulkheads to accept the new sync connector?

[Viz'art 24]

Its not clear wether you are using Nikonos type bulkhead connector on the housing or if they are Ikelite type.

 

What James is refering to is the actual cables, they have a non conducting threaded part that goes into the Nikonos type bulkhead of the housing,

 

If you have Ikelite bulkhead on the housing then your cable will have the same configuration on both end, in the case of a Nikonos type the cable has one end very different than the other.

 

If you have any doubts post a shot of the usual suspect, it help to see the configuration

[jong@seaotter.com 0]

Its not clear wether you are using Nikonos type bulkhead connector on the housing or if they are Ikelite type.

 

What James is refering to is the actual cables, they have a non conducting threaded part that goes into the Nikonos type bulkhead of the housing,

 

If you have Ikelite bulkhead on the housing then your cable will have the same configuration on both end, in the case of a Nikonos type the cable has one end very different than the other.

 

If you have any doubts post a shot of the usual suspect, it help to see the configuration

 

Yes, sorry for the confusion!

 

What I have is:

 

seacam housing with:

• aluminum ikelite pinout bulkhead connectors
  
• 'normal' ikelite dual sync cord
  
• new zincs under the handles
  

 

I've noticed that it results in pitted corroded bulkhead connectors over time. Obviously the bulkheads have to be aluminum or I'd be having this problem between the housing itself and the bulkheads, which would be far more insidious.

 

Here is an slightly crappy image of the corrosion with the sync cord just pulled out of the bulk head to expose the o-ring. You can clearly see the pitting in the threads of the bulkhead connector. In addition the 'rim' of the bulkhead is also pitted. As long as the pitting doesn't go through the thread wall I am safe, but if it goes through below where the o-ring from the sync cord sits......

 

All this despite careful rinsing after every immersion.

 

 

[james 0]

Hi Jon,

 

Very interesting! The bulkheads are clearly a different Al alloy than the housing (which is Eloxal coated) and the other bits and pieces.

 

In addition, the cathodic potential between the housing/bulkheads/sync cord is higher between the sync cord and the bulkhead than it is between the housing and the sacrificial anodes (aka zincs) so all of the corrosion is going there, instead of to the zincs.

 

One thing that occurs to me is that the bulkheads may not actually be in metal-to-metal contact with the housing. Isn't there an o-ring in between the bulkhead and housing?

 

So you may have a small corrosion cell between the bulkhead, threaded insert, and Ikelite sync connector. That could be remedied by putting a small zinc onto the bulkhead.

 

Cheers

James

[StephenFrink 9]

Yes, sorry for the confusion!

 

What I have is:

 

seacam housing with:

• aluminum ikelite pinout bulkhead connectors
  
• 'normal' ikelite dual sync cord
  
• new zincs under the handles
  

I've noticed that it results in pitted corroded bulkhead connectors over time. Obviously the bulkheads have to be aluminum or I'd be having this problem between the housing itself and the bulkheads, which would be far more insidious.

 

Here is an slightly crappy image of the corrosion with the sync cord just pulled out of the bulk head to expose the o-ring. You can clearly see the pitting in the threads of the bulkhead connector. In addition the 'rim' of the bulkhead is also pitted. As long as the pitting doesn't go through the thread wall I am safe, but if it goes through below where the o-ring from the sync cord sits......

 

All this despite careful rinsing after every immersion.

 

Jon - Use the new Ikelite connectors, which as James says are delrin at the thread end and look like this below. Delrin to aluminum will not corrode in the presence of salt water and electrical current.

 

 

Here's the wild card though ... I'll have to check with Ikelite to confirm that Ikelite to Ikelite cords are available with delrin threads. This is the Nikonos version pictured. I don't know why it would matter what thread part they put on the shaft. Actually, it might be that their threads are stainless in the cord you have. Whatever it is, they are dissimilar metals and electrical current is running through, hence the electrolysis.

 

The sacrificial zincs can't help for this as the metals are in contact before they interface with the zincs, which are actually on the housing, beneath the handles.

 

The answer is a delrin thread for the cord (from Ikelte), or unscrewing the cord from the housing after use.

 

It is the combination of salt water that stays in contact with the dissimilar metals (the O-ring is on the inside synch port) while the strobe is turned on that creates the problem. Rinsing it really does little good as the salt water was forced to all areas on the outside of the O-ring under pressure, and a freshwater rinse on the surface won't displace it so long as it remains threaded in place.

[jong@seaotter.com 0]

Jon - Use the new Ikelite connectors, which as James says are delrin at the thread end and look like this below. Delrin to aluminum will not corrode in the presence of salt water and electrical current.

 

Yes, this was my next move for certain - but it means replacing my bulkheads with nikonos, as ikelite doesn't make an ikelite pinout connector in delrin, only the nikonos.

 

The answer is a delrin thread for the cord (from Ikelte), or unscrewing the cord from the housing after use.

 

It is the combination of salt water that stays in contact with the dissimilar metals (the O-ring is on the inside synch port) while the strobe is turned on that creates the problem. Rinsing it really does little good as the salt water was forced to all areas on the outside of the O-ring under pressure, and a freshwater rinse on the surface won't displace it so long as it remains threaded in place.

 

Yes, I do unscrew the cord and rinse underneath it (holding it in place to prevent water intrusion past the inner o-ring) after almost every dive, but there are times when I'm in a zodiac in nasty seas that I cannot do so, and it must be those days (where it all stays locked up for the whole day on the water) where this corrosion really gets going.

 

As I mentioned above, I've been in touch with Ikelite, and they do not make an ikelite pinout sync cord, so I'm gonna have to switch all my bulkheads and sync cords (not cheap! dammit!) to the delrin nikonos sync cords and nikonos bulkheads.

 

This might be something that you put in your field notes on your seacam website Stephen, as I'm on my third bulkhead at this point...

 

Thanks for the feedback guys, it's confirmation of what I figured needed done, but looking at the price of replacing all my camera->strobe connection hardware, I wanted a second (or third) opinion. I'd rather spend the money on cylinder fills for dives!

 

Cheers!

[jong@seaotter.com 0]

Hi Jon,

 

One thing that occurs to me is that the bulkheads may not actually be in metal-to-metal contact with the housing. Isn't there an o-ring in between the bulkhead and housing?

 

So you may have a small corrosion cell between the bulkhead, threaded insert, and Ikelite sync connector. That could be remedied by putting a small zinc onto the bulkhead.

 

Cheers

James

 

Hey James!

 

There is an o-ring between the bulkhead and housing - but the problem is definitely between the sync connector and the bulkhead, and zincs on the housing won't help that. I suppose I could try and jerry-rig a small zinc to the bulkhead to try and reduce the current flow, but in the end I think it's going to be a much better solution to replace my camera->strobe hardware so that I can use the nikonos delrin sync connectors and not worry about dissimilar metals causing a charge and eating my aluminum bulkheads.

 

There are enough gear related things to worry about with this profession as it is...

[StephenFrink 9]

This might be something that you put in your field notes on your seacam website Stephen, as I'm on my third bulkhead at this point...

 

Cheers!

 

Jon - I think that if we can't get a delrin connector for Ikelite to Ikelite, we'll only recommend Nikonos V, or preferably S6, to our Seacam clients in terms of housing synch ports from now on. You are absolutely right ... there are times when you are at sea that you can't be running back to the rinse bucket to obsess over the threads on your bullkhead connectors.

 

Thanks for your insight, and as you know, we'll do what we can to resolve the issue, one way or another.

[UWphotoNewbie 1]

I would contact Ikelite. They have always been willing to make custom components when required. Perhaps they can make a delrin version.

 

The issue is really with Seacam that created the "Ikelite compatible" bulkhead connector that isn't quite compatible with the Ikelite spec. Compatibility means more than just electronic and geometric but also materials compatibility. No doubt this compatibility was a consideration with delrin Nikonos connectors.

 

Still, Ikelite may be able to solve your problem with a custom delrin connector. If I were you, rather than replacing all your sync cords, I would just get the new TTL convertor (Ikelite on one side and Nikonos on the other). This way at least you will be upgrading to something rather than throwing gear away. I think you'll want the TTL anyway. It still supports manual if you still want it.

 

Good Luck !

Edited May 30, 2007 by UWphotoNewbie

[james 0]

I would avoid putting a Nikonos bulkhead back onto your housing. They are horrible! If you HAVE to make a change due to the corrosion reasons - then I would change to S6

 

Or you can do what William suggested.

 

Cheers

James

[jong@seaotter.com 0]

Jon - I think that if we can't get a delrin connector for Ikelite to Ikelite, we'll only recommend Nikonos V, or preferably S6, to our Seacam clients in terms of housing synch ports from now on. You are absolutely right ... there are times when you are at sea that you can't be running back to the rinse bucket to obsess over the threads on your bullkhead connectors.

 

Or perhaps there is no rinse bucket to begin with...

 

But, yes, I think this is a good path for new customers going forward - for obvious reasons you can't put a ikelite metal compatible bulkhead in place, as that just moves the problem to the bulkhead<->housing interface, which would be even more insidious.

 

So having the cord connector be delrin (in some form or the other) seems to be the safest option.

 

I will admit that I am completely ignorant of what an S6 connector is...

 

Thanks for your insight, and as you know, we'll do what we can to resolve the issue, one way or another.

 

Yes, the service from you guys has always been top-notch, and I completely appreciate it! Let us know what the best path is for fixing this problem, and I'll just hang tight for now.

 

Thanks Stephen!

[jong@seaotter.com 0]

I would contact Ikelite. They have always been willing to make custom components when required. Perhaps they can make a delrin version.

 

I've contacted ikelite about ikelite pinout connectors in delrin, but they have responded that they don't make them. I didn't push at all or talk about custom pieces, but that's definitely an option!

 

The issue is really with Seacam that created the "Ikelite compatible" bulkhead connector that isn't quite compatible with the Ikelite spec. Compatibility means more than just electronic and geometric but also materials compatibility. No doubt this compatibility was a consideration with delrin Nikonos connectors.

 

True. Although to be fair to the seacam ikelite bulkheads, having the bulkhead material non-aluminum, only moves the corrosion problem from the threads of the bulkhead to the bulkhead<->housing interface, which I think is a more insidiouos place for it to occur.

 

Still, Ikelite may be able to solve your problem with a custom delrin connector. If I were you, rather than replacing all your sync cords, I would just get the new TTL convertor (Ikelite on one side and Nikonos on the other). This way at least you will be upgrading to something rather than throwing gear away. I think you'll want the TTL anyway. It still supports manual if you still want it.

 

Good Luck !

 

Thanks. I'll look into the cord upgrade if Stephen and Liz can't perform their usual magic for some reason!

[james 0]

That's interesting news Jon. I have an Ikelite sync cord for use w/ Nikonos strobes and because of the horrible corrosion problem there, the thread-on part is delrin. I don't see why they can't make a thread-on part for the Ikelite's that Delrin also.

 

If you guy the actual bulkhead from Ikelite, it cames with the chrome looking part, not the dark aluminum socket. You should investigate that. I think Eric Cheng had an Ikelite bulkhead installed on his old Sea and Sea housing and it worked great.

 

Cheers

James

[jong@seaotter.com 0]

That's interesting news Jon. I have an Ikelite sync cord for use w/ Nikonos strobes and because of the horrible corrosion problem there, the thread-on part is delrin. I don't see why they can't make a thread-on part for the Ikelite's that Delrin also.

 

If you guy the actual bulkhead from Ikelite, it cames with the chrome looking part, not the dark aluminum socket. You should investigate that. I think Eric Cheng had an Ikelite bulkhead installed on his old Sea and Sea housing and it worked great.

 

Cheers

James

 

I don't either, but they didn't seem interested in doing so...

 

If I buy the bulkhead from ikelite, it just means moving the potential for corrosion from the cord/bulkhead connection to the bulkhead/housing doesn't it?

[StephenFrink 9]

I will admit that I am completely ignorant of what an S6 connector is...

Thanks Stephen!

 

Hey Jon - Didn't want to hijack your thread, so for info regarding S6, surf over to http://wetpixel.com/forums/index.php?showtopic=19246