Soldering Cells in place

Padowan

I have had one or two cell errors recently which have been attributed to corrosion/black-slime on/in the molex connectors. I was thinking of putting the unit in for a new loom with the new co-axial connectors in, but then thought that a possible solution to this problem would be to solder the cells to the loom and remove the molexs completely - I could also solder my Shearwater HUD to the pins too, which would then eliminate all the mechanical connections that are prone to fail in this way.

I am well aware that soldering the cells in would make cell changes and removal a b1tch, but apart from removing the cells anually to replace, or removing them to clean the pins I've not found another reason to remove the cells. If they were soldered in, then hopefully one of the reasons for removing them goes away, and I can live with re-soldering things on an anual basis.

Any thoughts on this?

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decoweenie

The cells in my Shearwater-YBOD conversion are soldered.

Carl insisted so I let him has his way eventhough I can't solder to save my life. This is to test it out to see how much better it will be comparing to Molex as far as corrosion is concerned.

If I miss any diving because I can't change the cells out on the boat, I will kill Carl afterward - but that's a different issue...

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Dutchy

Phi,

I'm not sure why you claim not to be capable of soldering but in most cases I've encountered it was because people didn't have the right tools.
If you get yourself a 12Volt (or 220V if you have that availble on board), 18Watt (somewhere between 14-20 Watt should do) soldering iron and a decent multi core tin (dont save on that!) then you can make a good emergency repair.

Just a few more tips:
Allow it to heat for a few minutes. (for a beginner gas powered is no good and neither are the quick heating ones)
Clean the tip and allow some tin to melt on the tip first then rub it off and do it again.
Now you are ready to easily fix stuff... make sure you repeat cleaning the tip as soon as the tin is no longer very shiny.

I have years of experience in soldering and still see a lot that can be done better but usually it is those basics that people dont get right.

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Ben Field

Yes it would be a PITA but with a small gas powered iron and a steady hand you could change them on the boat.... rather you than me though!

The cell to loom plug comes under fire for corrosion issues on alot of rebreathers- isn't there anything better on the market?

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Know your PPO2, Pre-breath, Use checklists, Validate cells at 6mtrs, Use pure O2 at or near surface, Use a BOV, Don't dive Solo, Change Slime and Cells as recommended by Manufacturer and RTFM!





www.hugsac.org.uk

Ivon

The new co-axial conectors are a lot better, never had an issue with mine.

Mdemon

If you solder, you'd have to make sure you don't kill any of the sheath and would probably have to seal/pot the loom-side of the solder joint to stop fluid being wicked up the wire braid inside and killing the wire again. This is similar to what Paul does on the rEvoDream. e.g. pot the joint with hotglue and shrink some sleeve onto it. I've had this done on the molex but it doesn't stop the crimp itself from going, just saves the rest of the cable.

A better solution, IMHO, is to cut the molex off back to good wire (assuming you don't want to do a complete rewire with marine cable) and then connect a coax connector. These can be sealed in a way that molex can't - there will never be any braid exposed. The only reason I haven't done this yet myself is time, as I'm fed up with replacing/re-crimping molex connectors.

HTH

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"small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!"

The WRONG Attitude will get you killed.

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Padowan

The other issue I have with changing to the co-axial connectors is how to splice in the Shearwater HUD?

I'm reluctant to make some Y-Pieces with one co-axial, and one Molex connector, as that's not only introducing more possible corrosion points, but also (most critically IMO) adding an additional (2nd) mechanical connection in the primary monitoring and control circuitry.

Soldering will remove ALL the mechanical conenctions in both the primary control (YBOD loom) and secondary monitoring (HUD) circuits.

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Mdemon

Fit the coax connector. Cut into the wire somewhere sensible to remove insulation and solder the shearwater to the appropriate conductors. Pot with something suitable and shrink some heatshrink sleeve onto it for a rock solid connection.

Best of both worlds.

__________________
www.southwestmafia.com

"small minds talk about people, Average Minds Talk About Events, GREAT MINDS TALK ABOUT IDEAS!"

The WRONG Attitude will get you killed.

"Once the agenda-monkeys and perfect-worlders have moved on, perhaps we can do some diving?"

Tom Rose

I have always solder connections and never had a problem but....

1. Make sure you do not over heat the cell. To prevent that...
Pre tin (this means put some solder on the wire to be connected
Pre tin the cell pin using the technique discussed earlier
Bring them together and wrap...making sure solder touches solder
Get a little solder on your irons tip and bring it to the solder joint
between the cell pin and the wire
Attach a hemostat between the wire connection and the solder point
As soon as the solder melts remove the heat

2. Another approach I am in the process of trying is gold plating the wire and pins. An inexpensive gold plating kit is available

Caswell Inc. - Plug N' Plate® Brush Plating Systems

I use these kits to nickel plate brass fittings I make and purchase....

3. Also have you tried pro gold contact protection?

Good Luck

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wizbang

Another vote for the soldering but take the warnings seriously.
Get prepared and DO NOT over heat the:
pins, wires, cells, coatings anything.


I have the new co-axials and i am also as happy as larry so far.
(touching lots of wood)

My glitch with the co-axial is having ready spares. I have two now but there is not another co-axial cell here in Perth (that the gang knows of) which makes "borrowing " a cell to save a dive is out of the question.

I will be making an adapter to be able to use a molex cell on a co-axial wire.

Anybody know what the connectors are called or have a part number or link or wants to post me a "male" plug.?

Thanks Wiz