Covered Topics

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Monday, April 26, 2010

Industrial Cleaning with Household Products

I have worked on lots of machines in my lifetime - cars and trucks, motorcycles, small engine powered equipment, HVAC systems, and most recently - machine shop tools. Part of the service usually involves cleanup of oil, grease, dirt, and/or other contamination.

In recent times, it has been increasingly difficult obtaining the solvents needed to get real work done. "Alkabrite(R)", which I'm told is basically an industrial lye solution, is no longer accepted in my area for use on kitchen refrigeration equipment. Many refrigeration houses I've talked to no longer carry it at all. A shame, as it is useful for de-greasing machinery of all types as well as for cleaning refrigeration and HVAC coils. If you work on cars you no doubt are familiar with Berryman's Chem-Dip(R) in the red, white, and blue bucket for carburetor cleaning. This, too, is becoming difficult to buy in many areas due to the restrictions on volatile organic compounds (VOCs).

Especially if you are unfortunate enough to live in the Southern California Air Quality Management District (SCAQMD), you may even find it difficult to purchase the so-called "eco-friendly" stuff. Some suppliers won't sell it to you unless you work for an auto repair shop, and when they do, they charge outrageous prices for the stuff.

Here, for what it's worth, are some workarounds I've found using readily available household products:

Simple Green(R)

Simple Green is relatively non-toxic and, as far as I know, non flammable. Unlike carburetor cleaner it will NOT asphyxiate or poison you with fumes, nor is it caustic to skin like Alkabrite(R) is. In aerosol form it is a lung and respiratory irritant, but used with care I have found it to be relatively safe compared to solvent based cleaners. Here's two unconventional uses I have found for this inexpensive and readily available product:

Air Conditioners Simple Green(R) works great for cleaning air conditioner and refrigeration coils. If the coils are dirty, performance will suffer and the evaporator (indoor) coil may freeze up due to restricted air flow. Filters should be changed at least once a season; the coils should be cleaned annually.
When I used Simple Green(R) commercially on motel window A/C units, I was amazed at how well it removed the several years' build-up of resinous tobacco grime and dirt from them. To do this, use plastic bags and duct tape to protect the motor and any other electrical parts. Fill a plastic spray bottle with a 50/50 mixture of Simple Green(R) and hot water. Spray this mixture on the coil and let it sit for 5-10 minutes. Using a garden hose and trigger-activated spray nozzle, carefully direct a spray of water through the coil from the INSIDE of the unit outward. Work slowly back and forth over the entire coil area. This will lift away much of the dirt and grime; the spray will also physically dislodge any impacted material from between the coil's aluminum fins. If there is still grime in the fins or on the surface, repeat application. Shine a flashlight through the coil from the back side - you should see light clearly through the fins - refracted only by water droplets. Depending on what was previously on them, the fins may be stained or oxidized, but there should be no oil, dirt, or grime left. When you are done, use a compressed air source to blow the excess moisture out of the fins and off of any other parts or assemblies. Do the "flashlight test" again - it should show a nice, clean coil free of any debris or obstruction.

1) This seems obvious, but I'll say it anyway: You need to remove the unit from the window or wall it is installed in BEFORE trying this. I typically used a sidewalk, parking area, or driveway where I had a hard, dirt-free surface on which to work.
2) MAKE SURE all electrical parts are THOROUGHLY DRY before applying power - if you are unsure, or if you know water has leaked past your plastic bags and tape, use compressed air to blow any moisture from them and allow the unit to air-dry for a couple days.
3) I've used this technique on central HVAC systems, too, and it works quite well. You will have to be VERY careful of how much water you use so you don't overflow water out of the evaporator pan and onto your floor. Apply the water spray in short, quick blasts, allowing time for the water to be carried off by the drain. Depending on the design of your particular air handler, you may need a piece of sheet metal or thin plywood behind your coil to redirect spray and splatter back into the evaporator drain pan. Also, you will likely need to remove the squirrel cage blower from the unit to avoid getting water in the motor on these units.
4) Don't forget to do the OUTDOOR coils - as these also need cleaning.
5) Last but NOT LEAST: Be careful with the compressed air source - you can "mash" or collapse the fins if you use too much pressure. This will restrict the air flow when the unit is placed back in service. If you do mash some fins, use a "fin straightener" purchased from an HVAC supply house to GENTLY straighten them. This tool consists of a short handle with several interchangeable plastic "combs". These have teeth of differing thicknesses for different fin spacings. Use the one which most closely aligns with your coil's fins.

A couple years ago, I needed to clean the carburetor on my 20 year old portable generator. While I do have a bucket of Berryman's Chem Dip(R) for doing this sort of thing, I'm saving it for use only in an emergency or on the toughest jobs. Simple green(R) again came to the rescue here. Mix a 50/50 solution of Simple Green(R) and water sufficient to immerse the entire carburetor. Heat this in a metal container (NOT a pan you ever plan to cook food in!) on the stove to about 120 degrees F. This is somewhat hotter than bath water and warm enough to assure fast results, while still safe for most plastic parts. When I did this, all the garbage on both the outside and inside of the carb literally melted away in seconds! It made short work of the grayish colored gook left from gasoline that had sat in the float bowl for a couple years.
Disassemble your carb and soak the parts in the customary manner. I use a kitchen strainer for holding the small parts. I tie a wire to the large parts for dipping them in the hot solution. Periodically agitate the parts; I find that 20-30 minutes in the soak is usually plenty. When you are done, rinse your parts THOROUGHLY in running water. BE SURE to blow all the little tubes, ports, and passages clean with a compressed air source to remove dirt particles and water that could cause trouble later. Those cans of compressed air for blowing dirt out of PC cabinets work GREAT for this - and are a godsend for folks without access to an air compressor! The straw attachment on these cans allows you to direct the air blast right where you need it.

Neat Home-Made Goo for Removing Grease, Cosmoline(R), ...
Recently I helped a friend clean up some imported metal working equipment. This was coated with cosmoline(R) - a thick, toxic substance that often dries semi-hard and can be difficult to remove. Normally one would use some toxic cleaner bought from a hardware or auto parts store. Not wanting to use messy, toxic, and expensive chemicals - he came up with this substitute that's cheap, non-toxic, and actually works. With his kind permission, I have posted the recipe here:

Mix 2 - 3 parts lard (you buy it in a plastic tub at the grocery store) to 1 part vegetable oil. Use a fork and mash the ingredients together in a dish until you get a greasy paste that's roughly the thickness and appearance of phlegm. Adjust the ratio of lard to oil slightly as needed to get the desired consistency. Wearing rubber gloves, rub this mixture onto the surface that needs cleaning. Allow the mixture to sit. For something stubborn like cosmoline(R), you will want to allow an hour or more. Use a plastic spoon, plastic ice scraper, or the like to scrape off the worst of the mess. Use paper towels, followed up by a terry cloth shop rag, to rub the surface as clean as possible. If needed, re-apply the goop and let sit another 1/2 hour. Scrape off and wipe down as before. When you are done with this, you can either wash the surface with soap and water, then dry - or else simply wipe it clean with a fresh shop rag.

Bare metal surfaces should then be wiped with a light coat of machine oil to protect them from rust. Motor oil is okay in a pinch, too.

CAUTION: Remember that oily rags or paper towels can spontaneously combust under the right conditions - so dispose of these safely in a metal container.

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