# FF plug corrosion



## kingfisher111 (Jun 13, 2006)

I`ve noticed that one of the small connectors within my FF is being chewed away at the socket where it plugs into the back of the FF. I figure it may be the pin that carries the power into the FF and some form of electrolysis is eating it away. Don`t want it to completely lose contact as this would probably mean replacing the entire cable and transducer. Seem to remember Doug (D Gax) mention it at some time. Any ideas on a solution/ remedy? Steve.


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## Dodge (Oct 12, 2005)

I just give a puff with Inox which is OK on circuits and so forth Steve


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## beefs (Jan 30, 2006)

I do the same as Richo - good rinse, dry and fairly liberal use of Lanotec/Inox after each saltwater use.


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## Billybob (Aug 29, 2005)

Steve, you can get a special conductive grease from 'Leading Edge' or Dick Smith.

It's used for computer switch contacts etc. I find it's ideal for keeping salt water away from sensitive contact areas.

Unlike silicon grease it isn't an electrical barrier.


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## DGax65 (Jun 7, 2006)

Steve
If it is just a little surface corrosion you can sometimes clean it up. Try some electrical contact cleaner. The corrosion might just rub off with a little pressure. Just make sure that you don't put too much pressure on it and bend a pin. You might have to move up to some sort of abrasive if the corrosion is more severe. Scrape with a dental pick or an X-acto knife. Emory cloth also works, but it can be hard to get into the confined space in the connector. Even if you can't get all of the corrosion off, you might still get months or years of service out of it. As long as you can get metal to metal contact between the pins and sockets it should still work. Just clean it regularly and keep it coated with a di-electric grease. You don't have to use a huge glop of grease; just enough to completely coat all metal surfaces of the connector. Commercial electronics generally have small, cheap pins in the connectors. Unfortunately, it doesn't take a lot of corrosion to weaken the pins to the point of failure. This is exacerbated by the mechanical stress put on the pins each time you join the cable to connector. Fish finders seem particularly prone to these failures. They are often low to the water and get immersed or splashed on a regular basis. It doesn't take much salt water to cause corrosion on an unprotected connector pin. Fish finders are also frequently removed from their mounts. This is another opportunity for a small amount of salt water to get onto the pins. Once a pin starts to corrode, you also have more of a chance of it breaking off with each time you connect/disconnect the finder. If you use di-electric grease on the pins right from the start, your chances of having it last are much better. I also leave my fish finder on the mount even when launching through the surf. I have a plastic marine electronics cover that protects it from getting hit directly by the waves. You can also use a heavy ziplock bag over the finder. Just put the bag over the finder and put a rubber band or bungee around the bottom to hold it in place and provide a bit of a seal. I've had good luck with this method.
Remember that di-electric grease is exactly what it says it is; a di-electric compound. It doesn't conduct electricity. With the close tolerances of the pins and sockets in the connector this doesn't matter. The pins make direct metal to metal contact. If you put too much grease on the connector it might not work properly. I've found that the following method seems to work well. I put a large amount of di-electric grease on both sides of the connector and then press together. I check to see if the device is functioning properly. If it is, I will plug and unplug the connector multiple times and check for proper operation. If I'm not getting good electrical contact I clean up the connector with a cotton swap. I try to get rid of the gobs, but leave a good coat of grease on the pins. Check several times for proper operation. The key is to have enough grease coating the pins to prevent exposure to air and water. I always go on heavy and clean up if necessary. Here are a few pictures to provide a better illustration of what I'm talking about.

Commercial marine electronics cover for fish finder










Di-electric grease generously applied to FF connectors










After a particularly rough launch where I had gone through a couple of chest high waves my GPS stopped working. Within four hours of my launch the GPS was tits up. I thought that the batteries had died. I opened the back a week later and found serious corrosion on the battery terminals and throughout the battery compartment.










I immediately cleaned what I could with contact cleaner and alcohol. It still didn't work. With nothing to lose, I filled the entire battery compartment and the surrounding area of the case with di-electric grease. I went out a bought a new GPS (luckily on sale that week) and forgot about the old one for weeks. Several weeks later I cleaned up most of the grease and found that it had loosened much of the corrosion. I carefully cleaned the terminals and put new batteries in. It worked. The grease prevents air from getting to the metal and slows the oxidation. I think it also saturates the porous rust and makes it easier to remove. I now keep the terminals coated with a nice thick layer of grease. The GPS is still working 6 months later.










Notice that I've used liquid electrical tape to coat exposed screw heads and to seal the NMEA interface connector. This has also proven quite effective. You can also put a light coating of silicone grease on the o-rings and seals on your marine electronics to provide a better moisture barrier.

I may seem like a corrosion control nut. I can't deny it; I am. The first unit I was assigned to in the Navy Reserve was an assault craft unit. They operated air cushion landing craft (LCAC).










LCAC are large aluminum hovercraft that have numerous stainless steel fittings and components. Every second that they are on cushion they are surrounded by a cloud of salt water spray (and a cloud of sand while on the beach). Effectively, these craft are large batteries (dissimilar metals in a salt solution....that's a good design). As such, corrosion control is a never ending job. Waterproofing electrical connectors and components became a full time job. Rust, galvanic corrosion, pitting corrosion; we had it all. I treat my kayak like I did the LCAC. I know that if any metal is exposed to water or air it will probably rust.


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## DGax65 (Jun 7, 2006)

Billybob
I've never used conductive grease inside a connector for waterproofing applications. I've only used it for very specific applications in computers and radios. Making and breaking a connector repeatedly can cause the grease to be transported within the connector. If excessive amounts build up between pins you can get signal loss, reduced resistance paths or shorts. As I prefer to use a lot of grease for its properties as a physical barrier, it probably wouldn't be the best choice for my applications. How much do you use and how do you apply? I'd be interested to see how this works.


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## Billybob (Aug 29, 2005)

I must admit I've used it mostly on 12v connections but I don't see a problem with consumer FF transducer plugs as the power output is not that high.

I think, perhaps, that I should have described the grease as non-insulating, rather than conductive.

I use it on my anchor light cable fittings plus in and around the electronic speed control box that I made for my Minn Kota electric motor.


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## DGax65 (Jun 7, 2006)

Billybob
I might have been confused. There is conductive grease that contains either carbon or silver particles. This conductive grease is designed to reduce resistance and lubricate contacts. I don't think that it would be very good to use in multi-pin connectors.


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## Billybob (Aug 29, 2005)

Doug, the stuff I use is called 'Contact Treatment' grease.

It's a light brown colour and comes in a large syringe. Doesn't look like it's got anything tricky in like graphite etc.

I bought it a couple of years ago from 'Leading Edge' Electronics here on the Sunshine Coast.

I originally did a ring around all the electrical/electronic parts suppliers in the area (Tandy, Dick Smith) asking if they'd heard of or stocked a grease that I could put on electrical contacts to keep out dust, moisture and corrosive elements but which wouldn't interfere with the conductivity of the treated contacts.

'Leading Edge' had this stuff in stock and it was pretty much exactly what I was looking for.

Apparently it's used on multi-contact slide switches. Anyway, seems to work just fine.


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## DGax65 (Jun 7, 2006)

I've seen that in some switches that I've had to disassemble. I know that it's used, but I was unaware of its electrical properties. Di-electric grease has some drawbacks, but I really like the way it repels water and improves the sealing action of O-rings and gaskets. I might try some of that contact treatment in the future. I'd like to do a good comparative test to see which works better. Thanks for the info.


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## wopfish (Dec 4, 2006)

Hi Doug

I now know where the Thunderbirds fetish comes from - those military hover crafts are way cooooool dude. I once took the hovercraft across the english channel and it was the bestist, coolest thing. They are just awesome with all of that power. With the military one did they carry any weaponary and what was theyre main use??? Did they , have they been in any major conflicts. if so instead of blowing away their tyres, do you shoot up their skirts!!!???

Regards

Wopfish

sorry to hijack the forum but just had to ask!!!!


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## DGax65 (Jun 7, 2006)

Wopfish
I PM'd you so as not to hijack any further.


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## kingfisher111 (Jun 13, 2006)

Thankyou everybody for your input. Doug the pins in the back of the FF are still in EC. However just 1 of the sockets within the connector is being affected. I`d say that corrosion has chewed 1.5mm off the length of that 1 socket and as such it is slowly dissapearing into the connector. The residue salt is greeny blue in colour as perhaps Copper Chloride. At the moment the socket is still long enough to make contact with the pin. Will pick up some of that grease and apply liberally and watch to see if condition continues to worsen. Thanks again all for your input. Steve.


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## JT (May 25, 2006)

I have the same thing happening to my Garmin FF120. The greenish blue corrosion is happening in both the male and female parts on both the sounder and the socket. I have been a liberal rinser and Inox applier at the conclusion of each use and have been suprised at the rapid onset of the corrossion. My place of purchase has suggested that I return the whole unit as a warrantee claim. We shall see what happens.

JT


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## mickr (Jan 29, 2006)

Hi all just noticed this post and wanted to warn those that are using Inox for the contact pins on the fish finders. Case in hand - we purchased a new Max 20 some time ago and had the same corrosion problems (broke pin off inside unit so started using Inox on the replacement finder same unit Max 20 with the result that in the end the Inox destroyed the gasket seal and eventually the unit needed a new board which was corroded up - Your Hummingbird guys in Aus refused to replace the unit as they did the inspection and found Inox to be the problem (All NZ units are now sent to Aus for service and repairs which is a bummmer for NZ Hummingbird owners) so lesson learn't and we still have not purchased our replacement unit which is going to be a Navman with only one plug on the rear.

Happy Fishing


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## DGax65 (Jun 7, 2006)

Mickr
What is it about INOX that damages the gasket? Is the carrier a solvent?


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## mickr (Jan 29, 2006)

Sorry for the late reply .. really don't know but I bet if you contact Humming Bird I reckon they would pin it down for you, all I know is that they found that it had destroyed the seal and let water in to the internals and the result was corrosion of the board - to replace the board it was approx 120 dollars so I said don't worry.

Changing brand

 :!:


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