Soldering Tips

My experience is that soldering wires to batteries or to themselves is relatively easy and takes little experience if approached in a step by step way.

The Soldering Iron

Soldering irons come in price ranges of $5 -$7 for a 120volt 15 watt single fixed point, fixed temperature to several hundred dollars for adjustable temperature with replaceable tips of various sizes and tips. For occasional electronics assembly the 15watt iron will do as good of job as a more expensive Weller unit.

If the soldering iron you are using is new, clean the tip with acetone or alcohol and heat it up. As it is heating touch the rosin core solder tip to it. If the tip is clean the tip should be easy to coat. This is called pre-tinning. The tip of the soldering iron needs to be coated with solder to make efficient contact and help solder flow.

If the Soldering iron has been used previously it up and while hot, wipe it on a damp sponge. If the tip gets shiny you are ready to start your assembly. If it is not you may need to scrape or sand the tip and apply new solder. An easier way to keep your soldering iron tip clean and fully tinned is to purchase a can of tinning solder at the electronics store when you get your solder. It is a mixture of powdered solder and rosin flux. You just heat up the tip and push it in the compound. At the same time pick up a roll of de-soldering braid in case you get a blob of solder you want to reheat and remove. The braid soaks up excess solder. Get the widest braid you can because it can also be used as a conductor between batteries instead of round wire. In addition to the solder absorbing braid you might pick up a solder sucking bulb at Radio Shack or other electronic parts supply to remove large amounts of excess solder.

Third Hand Fixtures

Another handy tool to keep on hand is a couple of third-hand assembly fixtures. These devices usually consist of one or more large alligator clips attached by a multi- axial swivel to a heavy base. These can be used to position and hold wires and terminals together while freeing the hands to manipulate the soldering iron and solder tip during the operation.

Magnifying Glasses

If your eyes are as old as mine it will also simplify assembly if you have a magnifier. The ideal magnifier for bench work is a self lighted adjustable arm type such as an Electrix model #7452 available from Allied Electronics www.alliedelec.com . These are quite expensive but if you have a Granger www.granger.com close by you can get a magna visor which is worn like a pair of glasses for about $35. The same type of hood type visors can sometimes be found cheaper at a hobby store like Hobby Lobby or even some fabric stores which have hobby supplies. The only ones I have seen in fabric stores are pink, otherwise work the same. When you are not using it your wife might be able to use doing needle point. Just don't get her one for Christmas even as a stocking filler unless it is pink - experience talking here.


Side Note - Because of the tolerances in some battery cases keeping the solder joint as thin as possible is required to reassemble them. Preventing blobs helps assure this.. When talking about pre-tinning the wires after cleaning above, I mentioned leaving the strands fanned. Soldering them to the battery terminals in a fanned configuration helps to keep the profile of the solder joint thinner. Do make sure all the strands are bonded well with the battery to keep the wire current capacity intact.


On to Assembly:

These tips can also be useful when assembling your Hunting Game Trail Monitor Scouting Camera or the TrailEyes™ Game Pager™.

CAUTION: Never use acid core solder or acid flux for electronics soldering, the acid will corrode the copper and cause the joint to fail. Always buy small diameter rosin core solder.

Make sure parts are clean and free from dirt and grease. Wire used in the original installation is usually pre tinned or silver plated. You can tell by the silver cover. These wires only need to be clean, a Q-Tip and a little rubbing alcohol or acetone will usually clean them easily. The same goes for battery terminals. Another good cleaning method is a pencil eraser.  When soldering wires that are not already tinned – in case you had to replace them - first expose the ends spread the individual strands and scrape with a knife then twist the strands back to the shape you want them and heat them with the soldering iron tip while holding the rosin core solder below the wire. As soon as the solder melts and coats the wire remove the heat. Do the same with the battery terminal. This is called "pre-tinning". Press the wire lightly to the battery terminal, secure the work firmly and apply the soldering iron tip to the top of the wire. Touch the solder to the junction and as soon as it flows slightly remove the heat but keep the wire steady on the battery terminal or two wires if joining wires. The components should not need heating except for a couple of seconds.

  • Careful with the hot tip of the soldering iron. Remove and return the iron safely to its stand. They can ruin your day if you lay them on furniture or lay an arm on top of one while still running.

  • Never heat the battery but a couple of seconds with a cooling time between tinning and joining. Battery life can be shortened by heat and too much heat could even explode the batteries. See caution below for another reason not to hear batteries excessively.

  • Do not move parts until the solder has cooled. Any movement while the solder is still liquid will cause what is known as a cold joint and may fail completely later on.


CAUTION Most rechargeable batteries contain mercury, nickel, lithium and/or cadmium. These heavy metals can be very toxic. Cadmium is a known cancer causer. Federal law passed in May 1966 as the ‘Mercury-Containing and Rechargeable Battery Management Act’ requires that they be recycled. You can recycle old batteries at any retailer that sells them such as Home Depot or Radio shack.


First Aid For Burns

If you are unlucky enough to receive burns which require treatment, treat the burn as any other burn. Cool as quickly as possible. Don’t break blisters and see your doctor if it seems necessary. The Cold Heat Soldering Iron advertised on TV is a good choice for small jobs and now is available in retail stores.

This short soldering tip should be enough to do any battery replacement but if you want to become more proficient at soldering see the really good article at: http://www.epemag.wimborne.co.uk/solderfaq.htm  


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