How to remove corrosion on electrical conector?

omni550

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This is cross-posted (and a bit amplified) from my other thread about "Dishwasher leaking: Fix or Replace?" as I"m trying to get things buttoned-up thsi afternoon.

In the process of reassembling everything, I noticed that there's a lot of corrosion on the electrical connector that was attached to the circuit board on the base of the diverter valve. This is the general area where the water was leaking, so this corrosion developed over time.

I am attaching a photo of the OLD diverter valve circuit board to give you an idea of the level of corrosion. (BTW, there is a completely new diverter valve on the assembly that I am installing, so this is just to demonstrate the level of corrosion.)

I am hoping to reuse the old electrical connector. (As it is small and convoluted, the corrosion is difficult to see....which is why I am not attaching a photo of it.)

I tried mechanically scraping the connector with a knife, hoping to expose some clean metal to make a good contact.

My concerns are twofold -- 1) will this scraping expose enough metal in the connector to make a good contact when I reassemble things? and 2) will that electrical contact remain over time, or will the remaining bits of corrosion on the connector keep corroding and eventually break the contact?

Is there some way to clean the corrosion off the CONNECTOR easily? I saw a video online where they used 2 solutions: one is a super-saturated table salt & vinegar solution to remove the oxidation/corrosion, followed by a baking soda & water solution to neutralize everything from the first solution.
Does this work? or Am I better served by doing something else to get rid of the corrosion short- and long-term(and what would that be)? :confused:

Would spraying the connection with WD-40 be of any use?

(I have limited tools and supplies here, fwiw.)

omni
 

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I've used the baking soda trick more times than I can remember.
It is a bit messy so you'll want to be a bit surgical about it. In other words, don't overkill on quantity and be mindful of where the excess will or may drip.
I've never used the first solution you mentioned. (salt/vinegar)
 
I've used the baking soda trick more times than I can remember.
It is a bit messy so you'll want to be a bit surgical about it. In other words, don't overkill on quantity and be mindful of where the excess will or may drip.
I've never used the first solution you mentioned. (salt/vinegar)

Thanks, JPatrick. :flowers:

I am now encouraged to try this 2-solution method to remove the corrosion on the connector.

omni
 
You can find a good electrical contact cleaner at any auto parts store. Why not use something actually made for the job?
 
Looks like its working...

I have no idea where an auto parts store is around here. :confused:

I do have all the ingredients in my kitchen to do the 2-solution process. :)

I have been soaking the electrical connector in solution 1 (table salt and vinegar) for about 45 minutes (brushing with an old toothbrush now and then) and it seems to be doing the trick. I'll give it a bit more time and then plunge it into solution 2.

omni
 
Diet Coke...works great on auto battery terminals.
The pencil eraser works well for oxides like when you have a silver plated board sit too long before processing. I don't know how it would work on a thick growth.
I'm guessing you have a galvanic difference on the two sides of the connector which will cause corrosion growth like what you see. The water with other contaminates likely made it worse. It really depends on what is on both sides of the boards and connectors as to the best approach. Is the scrapped area where the connector goes? Is there much metal left under the area where scraped??
 
Must've gotten rid of that corrosion as DW is now working...

Diet Coke...works great on auto battery terminals.
The pencil eraser works well for oxides like when you have a silver plated board sit too long before processing. I don't know how it would work on a thick growth.
I'm guessing you have a galvanic difference on the two sides of the connector which will cause corrosion growth like what you see. The water with other contaminates likely made it worse. It really depends on what is on both sides of the boards and connectors as to the best approach. Is the scrapped area where the connector goes? Is there much metal left under the area where scraped??

Thanks, everyone, for all your great input. I learned a lot.

The corrosion issue was with the plastic (& exposed metal buried inside) connector. (I simply showed a photo of the old circuit board to give folks an idea of the level and extent of corrosion I was dealing with. I'm attaching a photo of what the corroded connector looked like, so you can see how the metal connections are internal and nearly impossible to see and reach. Bear in mind, this connector is small, about 3/8" wide.)

Fortunately, that corroded circuit board (simply posted to show the amount of corrosion) is now in the trash.

And my newly de-corrosified (is that even a word?) "clean" connector is attached to the new circuit board on the new diverter valve. :D

I just ran the reassembled dishwasher through a its maiden voyage (on a 1-hour cycle) and everything seemed to work OK and looks good so far! No evidence of water anywhere beneath the unit. :dance:

omni
 

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Pick up battery terminal cleaner spray from an auto parts store, spray it and scrape off as much of the green stuff. Then use Deox-it on it. That was the best product I used when working. Amazon sells it but might find it at auto parts store or hardware store.
Deox-it cleans and also coats to protect from further corrosion.
But I see you already finished your job. This is just for future reference.
 
Two recommendations for DeoxIT. I've not heard of it and will definitely look into it. Thx.

------------

BTW, I learn so much on the earlyretirement.org board. I am both impressed and grateful to all here who are so knowledgeable and willing to share. Many thanks. :flowers: :greetings10:

omni
 
FWIW I used WD-40 once on my car battery terminal to inhibit corrosion, and maybe a year later was having starting problems because it congealed into a goo between contact surfaces.
 
I was recommended CRC electrical contact cleaner by a few motorcycle and automotive friends as the best bet to spray contacts to address a starter problem. It is available at HD, Autozone, and even a few WalM. Going to get some this week and try it out.

Cheers!
 
Deoxit is recommended

. Good stuff

If high moisture area, coat the electrical parts in Vaseline - that keeps moisture and air from getting onto the contacts and reduces oxidation.
 
It was (still is?) common practice to clean gold-plated edge contacts on PCBs (printed circuit board) with a pencil eraser. This of course does not work with crimp terminal connectors that have inaccessible contact points.

I have used Deoxit on sensitive electronic switches, but have not tried the vinegar method (and would not on electronics). On the Web, many guys swear by it, and it seems to make sense on cruddy and less delicate connectors in cars or appliances, or power connectors. And using baking soda afterwards to neutralize the acetic acid in vinegar is a must.

By the way, some guys pointed out that this is also an excellent method to clean stranded wire ends prior to soldering. For heavily oxidized copper wires, soldering can be tough and requires a lot of soldering flux to cut through the oxidation. I will try this next time.
 
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Omni, Tim the Toolman would be proud of you!
 
The problem with Vaseline or other lubricants is it collects dust (and in open places, dirt) and that causes scratches and that causes sparking and that causes more rough surface and that causes ...


This is the same reason that a pencil eraser is not a good idea.
 
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