Reprinted from the ACJ - September, 1992
I realize that when I make the statement that today's common sense safety topic is soldering, several of you experts out there will let out a sigh and start flipping pages to see if the ACJ caught you on film at the latest regional show. You know who you are, the guys who have surgically replaced your right hand with a No. 2 torch.
Soldering is something you learned as a kid and perfected as an adult. With the advent of the aluminum core/plastic tank units, you may have seen a reduction in the amount of soldering work coming into your shop. Don't despair, there will always be some soldering work and aluminum repair requires brazing, so the art form won't disappear. But with the reduced need for soldering, your attention to safety may need a boost, so let's take a look.
It could appear as a prime time rescue show: accidental poisoning, burn victims, explosions, flames shooting from an uncontrolled gas line. I hope none of you are thinking, "I remember that day, what a bummer!" Tragedies like these are possible but also easily avoidable with a little attention to safety.
LEAD POISONING
Lead poisoning (I hear a few more sighs out there): You've heard a lot, learned a lot and cried a lot about it. I won't go into detail at this time, except to issue a couple easy rules of thumb. Lead gets into your body when you inhale dust and fumes and/or swallow dust and particles. Logic tells us to avoid these routes of entry to avoid getting lead poisoning. You can avoid breathing fumes and dust by installing a local exhaust system, and/or wearing respirators. Avoid ingestion by washing your hands; don't eat or smoke in the work area; don't bite your nails; don't bring dust home on your clothes, and wash those clothes separately or have a service provide uniforms.
Simply avoid allowing lead into your nose or mouth and you will reduce your lead worries a great deal. One exception is worth mentioning. Leaded gasoline can be absorbed through the skin, so take precautions to avoid that, too.
BURNS
Now some other soldering hazards. Number one is burns. A good rule is to control the torch tip like you would the muzzle of a gun: Don't point it at anything you don't want cooked. Wear gloves that resist heat. Remember, the piece is still warm long after you are finished, so keep an eye on curious customers. Be careful to avoid applying flame to the supply hoses. Many are only rubber, and a hose flapping around shooting flames usually doesn't impress customers or the OSHA guy. Never light a torch with a cigarette lighter unless holding a butane tank in a flame source is your idea of excitement. Fumes, not just lead but anything on your workbench, can vaporize. Fluxes, oils, coolant, paint, etc. are all fume sources.
Local exhaust is your best defense. Install it at each soldering station. Make sure there are no dead air zones in front of the worker. This is easily done by using a smoke candle or even a cigarette (not one you are smoking). Move it about the area and make sure all the smoke is taken up the exhaust and not into workers' faces. If exhaust is not possible, or inadequate, fume respirators are cheap and work well as a short-term, temporary fix. Be sure to match the cartridge with the fume type, test for fit and change the cartridge periodically. These same exhaust and dust mask rules apply when grinding or sandblasting a leaded piece. If you still are using a grinding wheel, get rid of it. You should do all of your blasting and grinding in a self-contained enclosure, like a bead-blast cabinet.
GAS EXPANSION
When a closed space is heated, the gas/liquid inside expands and can cause an explosion. Always provide an airway inside the work piece. Voids in the tank seam solder are possible and small explosions or spitting are common. Wear goggles or a face shield and enough protective clothing to keep from getting splashed. Long gauntlet gloves go a long way in preventing those attractive "solder freckles."
I hope this article didn't surprise anyone with new and exciting information; that wasn't the purpose. Hopefully, it did make you think a little about the hazards involved in your daily routine. Please step back the next time you are soldering and think about these common sense tips. The easiest accident to deal with is the one that never occurs.
The above article was written by David M. Brown, Chief Engineer of Johnson Manufacturing Company, Inc. and is published by JOHNSON with the expressed approval of the National Automotive Radiator Service Association and the Automotive Cooling Journal. Other reproduction or distribution of this information is forbidden without the written consent of JOHNSON and NARSA/ACJ. All rights reserved.
JOHNSON MANUFACTURING COMPANY
114 Lost Grove Road / PO Box 96 / Princeton, Iowa 52768-0096
Phone 563-289-5123 or Fax 563-289-3825