by Thomas Bonomo, K6AD —
I’d like to share with you my “secret weapon” for radio chassis cleaning. The dirtier the chassis, the better. Like many restorers, I’m not a fan of the “dishwasher method”, so I used to clean chassis the hard way: rubbing with a rag, a Q-Tip, or a soft brush dampened with some cleaning product. The results were usually only marginally satisfactory. Even using brushes, I was often unable to remove the accumulated crud from tight areas. The chassis looked noticeably better, but never like new, and there was always the risk of ending up with that dreaded “rubbed” look.
I have seen many, many chassis permanently marred by an eager restorer who supplants an inadequate cleaner with generous amounts of elbow grease, leaving behind swirls and a “rubbed” look. Fellow collectors have suggested many cleaners, and I’ve tried them all: Simple Green, 409, Windex, ammonia, etc. etc. These cleaners work to varying degrees, depending on the type of dirt to be removed.
There is, however, another type of cleaner from the automotive field that I’ve found to be far more effective. This product, made by Castrol, is called “Super Clean” and it is based upon a new chemistry in cleaners. This stuff instantly solubilizes oil, grease, and dirt and, most importantly, brown nicotine. This cleaner is not just another soap-based cleaner, yet is biodegradable and phosphate-free.
Here is the best way to use Super Clean, along with a few cautions. First remove all the tubes, then spray the chassis with Super Clean. Avoid getting any liquid into IF cans or transformers, or onto dial scales and painted surfaces. The idea is to get the cleaner only on the chassis. Within seconds, rivers of dirt and nicotine will begin to run off–even from around tube sockets, screws, and rivets that would otherwise require rubbing and brushing. Use a small brush to quickly and lightly go over all surfaces to loosen thicker accumulations of crud. After no more than one minute, rinse the chassis thoroughly with water (avoid getting water in the IF cans and transformers) and let the chassis dry for several days before applying power.
A few words of caution. Super Clean is strong stuff. First, dilute the off-the-shelf product 50% with water. A 50% solution is strong enough to produce the result you want. Second, keep it away from painted surfaces (like the front panel) except for short periods. You don’t want streaking. Third, do not leave it on the chassis for more than one minute. If you must contend with painted surfaces or silk-screened tube designations on the chassis, test a hidden painted spot before proceeding. Some paints are hardier than others. Following these guidelines, I have never had a problem, and I’ve probably cleaned at least eighty radios.
To help protect the chassis from tarnishing and corrosion after it has been cleaned, spray on a thin coat of silicone. Use water-based silicone (often referred to as food-grade silicone) rather than a petroleum-based product, which can attack rubber and some plastics. A commonly available water-based silicone is LPS Heavy-Duty Silicone Lubricant.
If a chassis is not permanently rusted or tarnished, this cleaning technique can often make a brown, nicotine-coated chassis shine like new. Collectors have looked in amazement at some of my “Super Cleaned” Collins amateur radios, thinking that they were new. Corrosion has never been a problem with this cleaner, either. Just flush the chassis well with water. Radios I cleaned back in 1996, including a Collins KW-1 transmitter, still work like a charm. Try this experiment yourself: clean a chassis with Simple Green, and then watch the rivers of brown flowing off the chassis during a subsequent Super Clean treatment. You’ll be amazed. Super Clean is available at most automotive stores and chains like Wal Mart. Simple Green and my other cleaners have now been relegated to more mundane tasks such as cleaning floors and toilets.