Dear Tom and Ray:
My wife says using our dishwasher as a parts cleaner is hurting our dishwasher. I say it is not. But I have learned to run an empty load after a load of parts so that all the dishes in the next load washed do not taste like transmission fluid. It avoids the kids spitting out their milk like they have been poisoned. I also have learned the length of the wash cycle, so I can complete the process before my wife returns home. As a backup system, I have learned to set a timer so that I remember to remove the parts. I try to wipe all the transmission fluid, brake fluid, power-steering fluid or engine oil from the parts before washing them. The dishwasher really cleans those parts. Please settle this disagreement.
RAY: I see two problems with this, David. Well, maybe more if you include your impending divorce and your kids hating you.
TOM: Problem 1 is environmental: You're washing petroleum products off of automotive parts, and sending them down the drain.
RAY: That means they're either contaminating your city's rivers and streams, or that that stuff is going into your septic system and potentially leaching into your own groundwater. Neither one of those, if you think about it, is a good idea.
TOM: Problem 2 is that you're potentially poisoning your kids. The reason they spit out their milk like they've been poisoned is because you're poisoning them: They're ingesting small quantities of petroleum distillates. This is also, if you think about it, not a good idea.
RAY: The key words being "if you think about it."
TOM: If you really want to use a dishwasher to clean your car parts, then you need to set up a separate dishwasher in your garage with an appropriate way to capture the petroleum runoff.
RAY: My suggestion would be that you take the family dishwasher -- the one you've already contaminated -- and install that in the garage. Then buy your poor wife and kids a nice, clean, new one.
TOM: And then, for a few hundred bucks, you can get a grease trap, which will separate out the contaminants from the waste water. Then you'll have to make arrangements to have the grease trap emptied and the toxins disposed of legally and properly.
RAY: And that doesn't mean using them to water the tomatoes, David.
TOM: If that sounds like too much trouble, a good alternative would be to make a deal with a local gas station or repair shop. Then when you need to clean parts, you pay them a few bucks to use their parts cleaner. They'll have a grease trap and a contract with a hazardous waste disposal service that comes once a week, or once a month, to collect the grease and grime and haul it away.
RAY: And probably dump it down their own kitchen sink!
TOM: Actually, no. Not unless they want to pay tens or hundreds of thousands of dollars in fines. The EPA takes that stuff very seriously.
RAY: But I'd say your dishwasher privileges are hereby suspended, David. Time to clean up your act and find another way to clean the parts.