Transmitter

[Andy StonemanParticipant @andystoneman15177]

I took my transmitter out of its box this afternoon and noticed a blue deposit on the bottom only battery terminals, As its not on the top terminals I am assuming that it could be salt water corrosion ? When i finish an afternoon sailing trip I always remove the batteries to prevent this type of thing happening. I have managed to clean off a lot of the blue deposit but not all, What should I use to clean the remainder off and what should I do to prevent this happening again, apart from being more careful I don't get water inside the transmitter.

Andy

[Andy StonemanParticipant @andystoneman15177]

I`ve got blue verdigre on the terminals

[Alan Fisher 1Participant @alanfisher1]

Personally I would clean off all the terminals using a fine brass brush and give a coating of vaseline to protect.

[ashley needhamParticipant @ashleyneedham69188]

OR an ink rubber perhaps or fine wire wool. Depends if it is just gunge on the terminal plating or if the terminal is corroded. Ashley

[Dave MilbournParticipant @davemilbourn48782]

Might be something worse. See here:

"From the RC Battery Clinic website…

The Black Wire Disease – What's the Cause?
The black wire syndrome is an occurrence in battery packs (Ni-Cds) where the negative wire becomes corroded (turns from shinny copper to blue-black). This is the result of either a shorted cell in the pack, the normal wearout failure mode of Ni-Cds, or cell reversal when a pack is left under load for an extended period. The sealing mechanism of a Ni-Cd cell depends to some degree on maintaining a potential across the seal interface. Once this potential goes to zero the cell undergoes what is called creep leakage. With other cells in a pack at some potential above zero the leakage (electrolyte) is "driven" along the negative lead. It can travel for some distance making the wire impossible to solder and at the same time greatly reducing its ability to carry current and even worse, makes the wire somewhat brittle. A switch left on in a plane or transmitter for several months can cause this creepage to go all the way to the switch itself, destroying the battery lead as well as the switch harness. There is no cure. The effected lead, connector, switch harness must be replaced.
This leakage creep takes time so periodic inspection of the packs, making sure that there are no shorted cells insures against the problem. The cells should also be inspected for any evidence of white powder (electrolyte mixed with carbon dioxide in the air to form potassium carbonate). In humid conditions this can revert back to mobile electrolyte free to creep along the negative lead. Some "salting" as this white powder is referred to, does not necessarily mean that the cell has leaked. There may have been some slight amount of residual electrolyte left on the cell during the manufacturing process. This can be removed with simple household vinegar and then washed with water after which it is dried by applying a little warmth from your heat gun.. "

A small bag of silica gel can be left inside the Tx case to absorb any ambient moisture, but never leave the batteries inside the Tx over the winter and keep all batteries in a warm and dry place. Plated wiring is much less likely to suffer from this phenomenon.

DM

[Andy StonemanParticipant @andystoneman15177]

Thanks Alan Iv`e cleaned off most off the gunk where I can see it, Unfortunately cannot get at the reverse of the folded back terminals, The terminal isn't corroded Yet ! Just the blue residue on it, so hopefully i can use your remedy Dave, thanks for the tip, I have silica gel in the R/C storage box all the time to help prevent moisture inside. Would the vinegar be just a solution or full strength Dave and how long should I leave it on the terminals ? The hairdryer sounds a good idea if I can smuggle it to my shed… I never use rechargeable batteries in my TX just replace them every time with fully charged dry cell 1.5V batteries so hopefully I should`t have the Black wire Disease. Very interesting reading ! Thanks for your help.

Andy

[Dave MilbournParticipant @davemilbourn48782]

Andy

This isn't black wire rot if you use only alkaline batteries. I imagine that neat vinegar will remove the remainder of the (alkaline) gunk on your terminal – just leave it on until the colour has gone then rinse off and dry. As has been suggested, a fine wire brush or wire wool will then shine it up again. To avoid leakage in future I would fit only the very best alkaline batteries – by which time you'll be paying as much as you wold for good-quality NiMH cells anyway. Moral? Buy some NiMH cells and a charger!

Dave

[Andy StonemanParticipant @andystoneman15177]

Dave,

Thanks, Its good to have it explained properly about the batteries The vinegar removal of the blue gunk went ok and I have now put vaseline on the terminals, I`m still scratching my head as to why it was only on the bottom set of terminals. No matter I will take your advice and buy some NiMH batteries and charger which sounds the better option financially. Do you get still the gunk if you use NiMH batteries ?

Andy

[Dave MilbournParticipant @davemilbourn48782]

Andy

I don't – but I have been known to follow my own advice on occasion!

Dave M

[ashley needhamParticipant @ashleyneedham69188]

I have never had blue gunk on my tx terminals, and the transmitters are kept in a builders tote bag in the (waterproof) shed, with their Nimh batteries permanently in place.

Luck of the draw?? some other chemical thing going on near where your transmitters are kept??

Ashley

[Dave MilbournParticipant @davemilbourn48782]

Ashley
I don't think that Black Wire Rot affects NiMH batteries in the same way. It may also happen that your radio has plated wire as its strands; the rot seems to affect only unplated copper wires. As regards my advice about battery storage (or anything else), you're quite at liberty to ignore it – I won't mind a bit!
DM

[Andy StonemanParticipant @andystoneman15177]

Ashley,

Not unless theres something else going on in the shoebox storage I don't know about, I`m still scratching my head as to why only the bottom terminals have the blue gunk on them, Maybe further investigation under the bonnet might throw some light on it.

Andy

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