Spider Corrosion, And Foul Odors, In Front Load Washers

[brucelucenta]

combo

That is good to know. If anything, I use too much detergent and wash nearly everything in hot water with the heat boost on. I also use bleach every so often also. I hope that means my machine stays clean and the spider doesn't corrode. I also always use the maximum of rinses it allows too and run the self clean cycle on occasion.

 

[askolover]

I'd love to see the spider in my 20 year old Asko, but I'm not going to disassemble it to see it until it is necessary. I've used bleach since it was bought new.

 

[kb0nes]

Well certainly there is some galvanic issue here at play, but it ISN'T the cause of a premature spider failure.

We do have two dissimilar metals in contact so there is a possibility of an anodic potential difference that could result in corrosion. We can only guess at what alloy the typical spider is cast from but it is likely some form of aluminum. The spin basket is some alloy of stainless. Assuming this there is a moderate difference of ~.50 V on the Anodic Index. Ideally in a wet corrosive application this potential difference should be held tighter then this to control any galvanic reaction.

But at this point we are now second guessing the engineers that designed these things. They considered this and they made it this way anyhow. Since a washer isn't like a ship that is constantly wet, this is likely acceptable within the design lifetime of the washer. The design lifetime is surely a minimum of 10 years with a margin for error.

Allowing biofilm and crud to accumulate on the spider holds the moisture in place constantly and accelerates the corrosion. John's empirical evidence of only seeing gunky spiders failing corroborates this. The fact that other front load washers live on much longer without seeing corrosion shows that there is something at play here more then just saying it is poor design.

Bear in mind that any new topload machine will likely be designed for the same design lifetime within a given manufacturers line. Using past performance to predict future trends may not be very accurate. Surely a modern Speed Queen top load machine will easily last 10 years, but a Speed Queen front load machine will outlast the top load machine and be easier to repair. But heaven forfend, the user may have to adapt a bit to use the appliance properly in order to reap the higher performance advantages of the front load machine.

 

[laundromat]

I think one of the causes of this stems from abuse. My cousin ruined her washers from just dumping liquid bleach freely into her washers. That caused corrosion and the entire front from the dispenser to the lower door area rusted out in two years. Way too much detergent and additives. The manufacturers have reasons to have markings on how much is enough. Dealing with Smiths Appliance , a local used appliance and furniture company, I see so many rusted out washers and dryers. Sad but true.

 

[bjconner]

Stray Voltage and Bearings.

I just helped someone who had badly corroded bearings as in several post above. They also look like bearings I have seen in some industrial installations.
Variable speed and sold state motor drives are known to generate stray electrical currents. Poorly designed control circuits can do the same thing. The current can be very small but still do damage.
Just where the currents are generated and where they flow is why they are "Stray".
In industrial use of 3 phase motor driven by VFDs currents can be generated in the rotor and pass through the bearings. The results looks like some of the pictures above. The fix in this case is buy motors with insulated bearings and install shaft ground systems. Shaft grounding is some kind of brush system that connects the shaft to ground.
I don't have a solution. I think part of the stray current may be through the water.

 

[henene4]

I highly doubt that. Electricly sped-up corrosion needs significant currents as well as any kind of agent acting as either oxidation or reduction agent. In a perfectly fine bearing, no electrolytic effects should ever occur.

The inducted currents are not big enough to cause anything in that matter. Further, on most modern machines, drums and thus shafts are grounded through the water to the heater, where build in.
And I don't even think most bearings are purely made out of magnetic compounds, me thinks that they used some cheaper aluminium alloy by now.

Is it that hard to believe that its just bad maintanace and bad material choices? Aluminium does corrode in chemicly highly reactive enviroments, and bearings with any kind of moisture in them break.
No need of stray currents, or what ever.

It's almost like the whole "microwaves kill food" story. No they don't, and any sane person with highschool-grade science knowledge should agree.

 

[tolivac]

There has been problems in motor bearings being heated by stray currents-but this is in VERY LARGE motors of hundred Hp or more.And this was BEFORE VFD's!GE addressed this issue by just that-insulating the front and rear motor bearings.I have a report about this problem from an engineer that worked at the DuPont polyester fibers plant that is in Kinston.Bought several tubs of books on this from a large yard sale.The engineer died and the family disposed of his books at the yard sale.Makes for interesting reading that I am still reading today.He worked there from like the late 1940's when the site opened to the later fifties.

 

[laundromat]

LEAVE THE DOOR(S) AJAR!!!!!

I have yet to have any issues ,other than used machines found that way,with mildew. When they have it, I use Spray 9 and hot water to remove it completely or replace the boot.

 

[panthera]

Spider thoughts, redux

I've never seen a clean spider stress crack and I worked in a used machine shop in Germany while my teaching credentials were being cleared. Saw several dozen.

Chlorine bleach WILL attack many aluminium alloys and I don't doubt it can contribute to failure in those machines not designed for it.

The amount of current needed for galvanic action between disparate metals is much smaller than most of us think, especially given the conditions of the water in which they are immersed. I'd not exclude the possibility that it plays some role - just how much I don't know. I'm linking to a familiar chart, though - and the conditions are met in a washing machine for the active metal (AL) to be eaten away. The question is, at what rate?

Galvanic Corrosion - SSINA

When two different metals or alloys are immersed in a corrosive solution or regularly connected by moisture, each will develop a corrosion potential. If the conditions for galvanic corrosion are present, the more noble metal will become the cathode and the more active metal will become the...

www.ssina.com

 

[norgeway]

Face It

The new machines are JUNK...The old Bendix and Westinghouse machines never had these problems...But then, they actually WASHED and RINSED properly....enough water and one direction tumbling!

 

[henene4]

One direction tumbling

Yeah, sure, let's go straight back to beating our clothing on stones and rinse them in a river. That sure has enough water for you and you controll everything about the cleaning process *rolls eyes*

Panthera, the current is indeed low, that is true. But you have to keep in mind you have to induce a voltage in the 0.1-1V range with currents of probably a few miliamps into sonething that is entirely not suited to be part of an inductive system.
Aluminium isn't magnetic in the first place, and neither is stainless steal if I remeber correctly, so no inductive currents their.
The bearings I don't know about, but they are far out of the dense parts of the magnetic field.
And these magnetic fields are highly trimmed and focused anyway, so the bit of stray magnetism that might get to the bearings will most likely not result in any significant current.

And yeah, as I said: The enviroments in washers are highly corrosive. Aluminium can corrode verry well under these circumstances. That's why plastic outer tubs are not inherently bad, they can't corrode at all.

 

[panthera]

Henrik,

I made no reference to the induced currents as I don't think there are any.

One needs no outside source of electricity - you have an anode (aluminium alloy), a cathode (stainless steel alloy) and a highly-conductive solution of water.

Americans use an enormous amount of chlorine bleach. I used oxygen bleaches in Germany.

Enormous difference.

 

 

[awr]

Galvanic corrosion on front loading washer spider CONFIRMED

I'm surprised that after 20 years of every manufacturer of front loading washing machines making the same design flaw by engineering a large battery in the form of washer tub that nobody has taken the three minutes it took to confirm the galvanic action.

See in my photos the before, during, after of my spider repair post galvanic destruction.

I used steel brush then sand blasting. I used JB Weld to hold the post in place then poured about 20oz of clear epoxy to make a solid puck that is also non conductive.

Notice in my photos I include the fact that some detergent paste as the battery electrolyte is generating 0.444v that's a lot of random voltage to be generating current 24/7.

The ions that generate that current come from the break down of the aluminum.

Notice that contrary to the original poster who is incorrect in his assessment, not only is voltage generated and measured, there is absolutely galvanic corrosion at the end of all the arms.

I suspect that there are multiple paths including the center bearing post as the cathode perhaps why the main corrosion is near the hub (but could be other reasons)

I'm just here to confirm with absolute certainty that galvanic corrosion does in-fact take place in all of these machines at any time there is an ionic liquid or paste touching both the drum and spider.

 

[johnrk]

awr

Thanks for your great photos and explanation--I've learned something here.

 

[toploader55]

very Interesting Research.

Thank You

 

[speedqueen]

This also fits with what John LeFever and others have been saying. With the washer being clean inside (no "Paste") the conductivity can only happen during the wash cycle. If there is build-up, the circuit would be constantly closed and the corrosion would always be happening.

 

[combo52]

Very Interesting BUT

The ONLY reason these spiders corrode is a mineral and scum build-up caused by improper usage habits of the machine by its users.

We have analyzed hundreds of FL washer spider failures right in the homes where the machines were used and I have never seen a spider failure where it was any surprise when we saw how the machine was used.

On the other hand even FL washers like the small door Frigidaire's that had a very thin spider never fail even when used commercially with lots of different users and lots of bleach to keep the spider clean.

Yes Andrew you have identified how these spiders fail, but you have missed the real reason why they are getting a mineral and scum build-up in the first place. When manufactures design and test their machines none would subject them to this type of neglect and poor usage habits that cause this crap to build-up.

Washing machines of all types have had failures from corrosion since the first wooden wringer machines and many of the reasons for corrosion damage were completely beyond the control of the manufacturer, just as a car manufacturer cannot control how cars are cared for and driven.

John L.

 

[Chetlaham]

Perhaps- but how is the user getting DC voltage then if there is no galvanic action?

 

[speedqueen]

Chetlaham

What Mr. LeFever said was that while Andrew(awr) found the direct cause for the failure, the cause of electrolyte remaining was poor washing habits, of which he has explained at length.

"Yes Andrew you have identified how these spiders fail, but you have missed the real reason why they are getting a mineral and scum build-up in the first place. When manufactures design and test their machines none would subject them to this type of neglect and poor usage habits that cause this crap to build-up."

A cause/effect chart.

{poor washing habits}--->{build-up}--->{electrolyte}--->{galvanic corrosion}--->{spider failure}

 

[Chetlaham]

Reply #117 claims it has nothing to do with Galvanic corrosion. Otherwise you would be correct.