responding to
formatting link
biguggy wrote: In my opinion there is no panacea to the problem of foul odours from front load washers. I have seen posts where it was stated to have been traced to the discharge pipe pushed to far down the drain pipe allowing water to siphon back into the machine. Most machines I know of have a non-return valve to prevent this, and prevent any water in the pipe draining back into the machine. These, even if fitted, may have been defective. I have seen posts where the smell has been stated to be traced to small items of clothing, baby clothes, sock(s), ladies flimsies etc. that have got stuck ?somewhere in the works? and are cheerfully rotting away. Use of excess detergent and/or fabric softener very often coupled with use of other than HOT water. This allows build-ups of these laundry aids to form and then start turning foul. HOT water alone will sometimes get rid of these build-ups. Sometimes the assistance cleaners such as ?Affresh? will help, sometimes not.
In my opinion there are two, normally overlooked, sources of these fouls odours: -
- The recesses in the hubs of the spiders fitted to many of these machines will retain water even after the fastest spin. This ?water? will contain, inter alia, unused laundry aids (detergent, bleach, fabric softener etc), soil, the products of the interactions between the laundry aids and the soil, the products of the interactions between the laundry aids and the chemicals in the ?tap? water, and ?unused? chemicals in the ?tap? water. When left over time the water will turn foul smelling. A photograph of such a build-up can be seen at: -
formatting link
removed that tub/spider from a machine owned by a relative.
- The products of corrosion on the spiders retain small quantities of water after the final spin giving the same result as above.
Many posts on many sites claim that the corrosion of the spiders is due to galvanic action. I do not agree, I believe it is primarily chemical corrosion.
Should the corrosion have been galvanic between the stainless steel drum and the aluminium spider the majority of the corrosion would have been at the junction of the two metals i.e. at the ends of the arms. I have seen no photographs of spiders corroded in such a manner, nor read of any similar descriptions.
Aluminium, and its alloys are corroded when immersed in an aqueous solution with a pH value above about 8.0 or below about 4.0 (nitric acid is a well known exception). All detergents have to be above about 8.0 or they would not work. The Material Safety Data Sheets put out by Proctor and Gamble state that the pH for one of the liquid ?Tides? is 8.0 and for one of the ?Tide? powdered detergents as 11.0. Bleach, (sodium hypochlorite) is also very corrosive to aluminium. I should add that for corrosion of the spider to take place these levels are considerably above the levels found in a washing machine during the wash/rinse phases of the cycle.
Sodium carbonate (washing soda) and sodium percarbonate found in some laundry aids (Affresh and Oxi-Clean [powder]) are also corrosive to aluminium, as is borax, provided the required concentrations are reached.
I believe the mechanics of the corrosion are as follows. Even after the fastest spin small quantities of water will remain on the shaft and towards the centre of the spider. Any recesses in the spider close to the centre will aggravate this situation. This water will contain ?contaminants? as detailed above. Should sufficient of these ?contaminants? be present the pH of the mixture can, as evaporation takes place, rise to a level where corrosion will take place.
Corroded spiders can be seen at: -
formatting link
a LG spider
formatting link
information on galvanic corrosion there is a very good paper at: -
formatting link
information on chemical corrosion of aluminium (or ?micro galvanic corrosion as the author calls it, I grew up calling it ?pitting corrosion) there is an informative paper at:
-
formatting link