Wednesday, July 14, 2010

Washing Machine Failure

New Washing Machine

My old machine is now leaking slightly from the bottom, and the bearing is going out so every load is accompanied by a THUMP THUMP THUMP during spin. And it is only getting worse.
I called an appliance repair place and described the problem, and they said yes, it would be more expensive to repair it than to replace it.

So, while looking around, I came across a "Buying Guide" for washing machines. I don't really need it, but a response (included below) made me realize that that is probably what happened to our machine.

Thanks, David, for your research and testing, and clear reporting of the results.

(From the website: http://www.appliance.net/2009/washing-machine-shopping-guide-1403)
David Field on Oct 11th, 2009 at 2:04 pm
Some of the front load machines have aluminium (Al) spiders connecting the spin drum to the drive pulley.
Aluminium is corroded by, amongst other things, sodium hypochlorite (NaOCl) otherwise known as ‘bleach’, Sodium carbonate, Sodium percarbonate, (these later two I found listed on the contents of a popular laundry aid), sodium Hydroxide (NaOH) (this one is sometimes used as a stabiliser in ‘bleach’ but I did not find it listed on the two containers of ‘bleach’ I found in our house).

To demonstrate what ‘bleach’ can do to aluminium just find a piece of scrap aluminium, without any coating, or remove the coating and let it sit in air for a couple of days to develop the naturally occurring oxide coating, then put one drop of ‘bleach’, straight from the bottle, onto the aluminium and leave it overnight. The following morning you should have a nice little pile of corrosion products on your aluminium. This is what can happen to aluminium components in your washer, albeit at a much slower rate because the ‘bleach’ is diluted.

To check if any of your laundry products are harmful to aluminium perform an Internet search for the material safety data sheet for the chemical concerned (e.g. Sodium Hydroxide Material Safety data Sheet).

I know these spiders are fitted to some ‘Kenmore’ (manufactured by Frigidaire) machines, some Frigidaire machines sold under their own name, and some GE machines. Very likely there are many others. Additionally any aluminium component in the water area is susceptible to corrosion.

This information has been passed to Sears and Frigidaire.
Sears advise that the information ‘will be passed to the appropriate departments’ but have refused to pass any further information on to us.
Frigidaire have assured us that they use only the best quality materials and that they will pass on the information to their design engineers, the very people who would have specified aluminium in the first place. Hardly re-assuring.

My wife and I have two Sears ‘Kenmore’ washing machines built by Frigidaire.
I recently had to tear down the old one (8 years old) because of bearing failure. Nothing to fantastic there, those bearings take one heck of a pounding. In addition to the failed bearings and failed ‘spider shaft’ seal, likely caused by the bearing failure, the brass sleeve on which the lips of the seal run was scored, by the spring in the seal, rendering it unserviceable.
What I also found on dismantling the machine was a build up of a deposit, resembling powdered detergent that had got damp and ‘clumped’ adhering, quite strongly, to the spider (a shaft [of steel], and aluminium hub with three spokes) which attaches to the stainless steel inner drum and the driving pulley. This ‘deposit’ would not flush away, as powdered detergent, being soluble in water, would have. I took my pressure washer to ours but still did not get it completely clean. Whereupon I discovered that the aluminium portion of the spider was quite heavily corroded towards the centre with almost no corrosion towards the outer third of the spokes.

At first I thought this was galvanic corrosion caused by the steel of the shaft and the aluminium of the hub. There is quite an informative paper on Galvanic Corrosion, use ‘Yahoo’ and search for ‘UN1001 Reactor Chemistry and Corrosion’ and open the link that gives ‘un1001_Galvanic Corrosion’, the authors are Lister and Cook. The ‘deposit’ though had me puzzled until I researched corrosion of aluminium and discovered that it is normally corroded when immersed in an aqueous solution with a pH value below about 4.0 or above about 8.0 (nitric acid is apparently an exception). Common household bleach (sodium hypochlorite NaOCl) is a strong alkali. I placed a drop of bleach, straight from the bottle, on an undamaged section of a spoke from my spider and a drop of vinegar (acid), which my wife favours, on another arm and left them overnight. The following morning there was nothing left of the vinegar and no signs of damage to the spider. Where the bleach had been was a small pile of a whitish powder, which resembled the ‘deposit’ and was also, for the portion immediately adjacent to the spider, quite difficult to remove.

Numerous detergents are alkaline, they have to be or they would not work, also alkaline are numerous other laundry aids. Reference to the ‘contents’ labels on the containers and the Material Safety Data Sheets (MSDS) on the Internet will give more insight. In addition to ‘bleach’ I have found sodium carbonate and sodium percarbonate in laundry products in our house. Sodium hydroxide, which is sometimes used to stabilize ‘bleach’, is also strongly alkaline, and corrosive to aluminium, it was not listed however on the two ‘brands’ of bleach I found in our house.

For some time prior to the bearing failure my wife had been complaining of a ‘moldy mildewey smell’ coming from the washer and leaving an odour on our laundry, particularly the towels. After I rebuilt the washer, new drum and spider, they are not available separately, together with new bearings and seal, it ran a lot quieter, no surprise, but here is the kicker, according to my wife ‘no smell’. Conclusion, the only thing different is no ‘deposit’. Now does the ‘deposit’ itself cause the ‘smell’ or does it collect undesirable compounds that cause the offensive aromas? I don’t know but it is certainly ‘food for thought’ particularly when I found two references on the Internet to people stripping their washers down and getting ride of ‘deposits’ which cured their ‘smell’. The odours, I fear, will return unless the owners alter their laundry habits.

To see what corrosion of aluminium can do perform an Internet search “Why Kenmore Front Loading Washers Fail” and watch the short video. I do not agree with the comment that it is galvanic corrosion between the spider and the stainless steel drum, should this have been the case one would have expected the spider to be corroded adjacent to its connection to the drum. Neither do I believe the deposit the gentleman showed to be caked detergent for the reason stated above (mine would not flush away).

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