LED Leads & Transistor Leads are rusting away.???

[gary350]

Every year I have to make 20 new circuit boards because the old ones are worthless. 2D batteries last about 1 year and LED wires rust completely through about the same time batteries die. Transistor wire rust completely though too. There never seems to be much rust on capacitors that is strange? Zip lock plastic bags were terrible now I use glass jars with air tight lids but still rust away. I tried open jars in AC in low humidity put new PC board with new parts & new batteries in the jars the screw lids on tight they still have water condense inside jars and parts all rust. I have tried incasing circuit boards in candle wax but wires still rust away.

Something interesting I noticed, circuit boards laying around on the work bench and shelves in the open air never rust but parts in jars do? That seems crazy to me.

LED flasher security lights are all outside in the weather 6 months of rain all winter & spring. You can see water condensed inside some of these jars. I was thinking about putting jars, batteries, PC board, lid in the freezer then open freezer and screwing on the lids quick, not sure if that will work or not?

Jars are working much better than zip lock plastic bags wires on PC boards have no rust but LED wire & Transistor wires rust completely away & those parts fall completely off of the PC boards.

Any ideas?

 

[Nigel Goodwin]

In one of your pictures the jar is obviously full of condensation, so it's got water inside it - hence the components rust, you can even see rust on the batteries.

Even assuming the jar is actually air tight?, there's moisture in the air inside the jar when you seal it. You might try some silica gel packs inside, see if that helps?.

You're also using really crap batteries - use alkaline ones instead, which will last much longer and be better value.

 

[gary350]

Silica gel packs inside the jars would be good if I had some. We live in TN average it rains 250 days every year, humidity is 100% most of the time. It is strange LED wires rust, Transistor wires rust, other wires no rust. YES I am using crap batteries they last 1 year and are 33 cents each. I can't see paying $2 each for better batteries they will need to last longer than 6 years to make them worth the extra cost.

 

[rjenkinsgb]

My thought would be that the batteries themselves are releasing some vapour that causes the corrosion?

Using higher quality batteries as Nigel suggests may change that.

 

[Nigel Goodwin]

Silica gel packs inside the jars would be good if I had some.

You get them in loads of stuff you buy, reuse them.

Or simply buy some.

[loads]

We live in TN average it rains 250 days every year, humidity is 100% most of the time. It is strange LED wires rust, Transistor wires rust, other wires no rust.

[/quote]

Why strange?, steel wires rust - the wires are steel. Try a magnet on a resistor!, or on the wire from a resistor.

YES I am using crap batteries they last 1 year and are 33 cents each. I can't see paying $2 each for better batteries they will need to last longer than 6 years to make them worth the extra cost.

If the cheap crap ones last 1 year, then the alkaline ones will probably last 6 years!.

 

[tronitech]

Conformal coating?

 

[unclejed613]

Silica gel packs inside the jars would be good if I had some. We live in TN average it rains 250 days every year, humidity is 100% most of the time.

go to a gun store (yes, really) and ask if they could sell you some silica gel packs. the silica gel packs that ship with rifles are usually pretty big ones.... they may also just have some for sale for people to use in gun safes, especially in such a humid climate. if the silica gel gets saturated, you put them in the oven at 125F for about a half hour or so to drive the moisture out, and you can re-use them.

 

[gary350]

I think it is strange only the LED wires & Transistor wire RUST. None of the other wires rust.

 

[Nigel Goodwin]

I think it is strange only the LED wires & Transistor wire RUST. None of the other wires rust.

Again, nothing strange - it depends what the wire if made of , and what it's coated with. Perhaps the resistor wires are better tinned?.

 

[gary350]

I checked wires with a magnet they are all steel except the ceramic capacitors that I am not using on this project. I wonder if some wires have a coating and LED & Transistors don't?

I have accidently done a typo or clicked something wrong. When I try to fix a typing error the letter after the error deletes. Example, Transidtor if I click the d the blue color square appears, when I type the new letter s the letter t disappears. If I try to replace t then o is gone. ????? How do I stop this???? I closed this page & left the form when I come back problem is still here. Not having this problem on other forums?

 

[rjenkinsgb]

When I try to fix a typing error the letter after the error deletes.

You have hit the "Insert" key and switched it off (to over-typing) instead...

 

[schmitt trigger]

I live in south Texas by the Gulf coast.
The trade winds blow from the south east, after transversing the Gulf of Mexico. It doesn’t get any more humid and saltine than that.
Every metallic object facing the winds will corrode.

But I have a small weather station which has survived 6 years.

The secret? Urethane based potting fully encapsulating the board.

 

[Reloadron]

If you seal a jar in a high humidity environment and the jar temperature drops below the dew point you are going to get condensate. Seal the jar in a dry air environment and place a small desiccant packet in the jar. Next you may want to try spraying the boards with a light coat of polyurethane as mentioned above.

Ron

 

[gary350]

If you seal a jar in a high humidity environment and the jar temperature drops below the dew point you are going to get condensate. Seal the jar in a dry air environment and place a small desiccant packet in the jar. Next you may want to try spraying the boards with a light coat of polyurethane as mentioned above.

Ron

I have been keeping jars with the PC board & batteries in the house in AC overnight then put lids on next morning. AC air is the best I can do for low humidity. Sometimes it works better than others. I notice a jar outside in full sun heats up like a green house moisture is always inside the jars I wonder if something is being cooked out of the batteries.

 

[AnalogKid]

You get them in loads of stuff you buy, reuse them.

Actually, silica packs are not an infinite sink for humidity. To reuse them properly, you have to dry them out. If they are used in a critical application, you have to dry them out per a specific procedure and follow-up testing. Had to deal with this for a MIL project. There is a thing that looks like a MIL 38999 circular connector that is a bi-directional air vent (bleeder valve) with a silica pack built-in. When air pressure equalizes as an unpressurized aircraft ascends and descends, the air that is intaken during descent is dried.

The driest ambient air available to the general public is inside a walk-in refrigerator or freezer at a restaurant. Buddy-up with a local McDonald's manager, take your jars and some new, sealed silica packs inside the walk-in, wait a minute, assemble and seal everything. Outside, when the jars warm up the internal pressure will be greater than the outside ambient. Crack the lids just enough to let the pressure equalize, and re-tighten.

Yes, I've done this; different packaging, and a co-worker's brother ran a Chinese restaurant. Worked like a charm.

ak

 

[Reloadron]

I like that. Seal them in a walk in fridge.

Ron

 

[DerStrom8]

Careful about what flux you use while soldering them to the perfboard. Some fluxes, if not cleaned well, will continue to eat away at certain metals. Try no-clean flux or, even better, thoroughly clean the board after soldering to remove all flux residue.

 

[audioguru]

Your circuit has only 2 LEDs and an LDR to turn it off in daylight. Then why are you using HUGE D cell batteries to power it?
Your circuit appears to be a simple 2-transistors multivibrator that does not blink the LEDs, instead it alternates the LEDs so that one LED is always turned on all night draining the battery.

I have many blinking LED circuits, The indoor ones have 10 LEDs that blink as a chaser in a circle going around and around all day and all night. I designed the circuit to blink each LED for a 30ms duration short enough for low average battery current but long enough to be seen as being bright. Then for my circuit to look as bright as yours, my batteries last (1000ms/30ms=) 33 times longer.
I use two name brand alkaline AA cells for the 2V red LED ones and use four name brand AA alkaline cells for the 3.5V blue ones. The batteries last for 3 months.

I have many cheap solar garden lights. They are made where your very cheap batteries are made. The solar lights used to use one very cheap AA rechargeable Ni-Cad battery that rusted away in 2 months, some transistors and resistors that rusted away like yours and used an LDR that got sunburned in 2 months. They came with one white LED.
Modern solar garden lights are still inexpensive but use a Ni-MH battery that takes one year to rust away which I replace with a western Name Brand one that does not rust and lasts for years. They use one IC that does not rust and use the solar panel to detect light instead of an old LDR. I replaced the continuous lighting white LED with a bright colors changing LED from Christmas, Halloween and Easter decorations. 5 of my modified solar garden lights use a small LED module that has red, green and blue LEDs blinking in a pattern.

I recommend that you blink your LEDs instead of alternating them and use a modern Name Brand battery that can be much smaller than what you are using.
You Tube has videos of cheap Super Heavy Duty batteries like yours that are cut open to reveal what is inside instead of battery chemicals.

 

[gary350]

Your circuit has only 2 LEDs and an LDR to turn it off in daylight. Then why are you using HUGE D cell batteries to power it?
Your circuit appears to be a simple 2-transistors multivibrator that does not blink the LEDs, instead it alternates the LEDs so that one LED is always turned on all night draining the battery.

I have many blinking LED circuits, The indoor ones have 10 LEDs that blink as a chaser in a circle going around and around all day and all night. I designed the circuit to blink each LED for a 30ms duration short enough for low average battery current but long enough to be seen as being bright. Then for my circuit to look as bright as yours, my batteries last (1000ms/30ms=) 33 times longer.
I use two name brand alkaline AA cells for the 2V red LED ones and use four name brand AA alkaline cells for the 3.5V blue ones. The batteries last for 3 months.

I have many cheap solar garden lights. They are made where your very cheap batteries are made. The solar lights used to use one very cheap AA rechargeable Ni-Cad battery that rusted away in 2 months, some transistors and resistors that rusted away like yours and used an LDR that got sunburned in 2 months. They came with one white LED.
Modern solar garden lights are still inexpensive but use a Ni-MH battery that takes one year to rust away which I replace with a western Name Brand one that does not rust and lasts for years. They use one IC that does not rust and use the solar panel to detect light instead of an old LDR. I replaced the continuous lighting white LED with a bright colors changing LED from Christmas, Halloween and Easter decorations. 5 of my modified solar garden lights use a small LED module that has red, green and blue LEDs blinking in a pattern.

I recommend that you blink your LEDs instead of alternating them and use a modern Name Brand battery that can be much smaller than what you are using.
You Tube has videos of cheap Super Heavy Duty batteries like yours that are cut open to reveal what is inside instead of battery chemicals.

AA batteries last about 3 months I don't like changing batteries on 20 PC boards outside every 3 months so I use D batteries they last a whole year. They don't all die on the same day location determines how long they last. Voltage is 3.2V for 2 batteries in series circuits stop working when voltage is about 2.7V. I have soldered 3 used batteries in series this get voltage up to about 4V lights sometimes only flash 1 week longer on old batteries this is a waste of time. Now I replace old batteries with new batteries. I have experimented with increasing resistor values to save power LEDs don't blink as bright but so what they are still very easy to see in the dark. Next time I build a PC board I will see how high resistor values can be and still get LEDs to flash and be seen. If I can reduce drain on batteries they should last longer.

 

[audioguru]

Didn't you understand when I said that your simple circuit alternates the LEDs and lights continuously, wasting battery power but my LED circuit blinks each LED brightly but uses 1/33 times the current that yours uses?
I see an LDR on one of your circuits. Doesn't it turn off the circuit in daylight?

Have you tried replacing the cheap old-technology batteries with new modern Name-Brand ones?
Guess why Sunbeam batteries are cheeeep? Old Sunbeam batteries are garbage from you-know-where and sit in The Dollar Store for years before being sold.