Thank you for the detailed basics on soldering. I was not even aware that I wasn't getting a nice 2 wire thing with a nice long lead. They sure don't cost much, I may just buy those "easy" ones and practice on the short lead diodes. And I'll check out the specs on the 3-lead diodes too.
"M. G. Devour" <mdev...@eskimo.com> wrote: Hi Max, I think you've set yourself at a bit of a disadvantage without realizing it. The easier way to go would have been to buy diodes with leads rather than surface mount. You may want to return them (if the vendor allows that) or write them off and order some with leads. I've never done anything with surface mount yet. If you put the following into Google, you'll get some guides to equipment and technique: "surface mount" "soldering technique" As you explore electronics you'll find a lot of hobbyist info and rub elbows with ham radio enthusiasts a lot. They are good resources. The most important things about soldering are clean surfaces, proper flux, and applying heat the right way... If you're using standard components of any kind, the leads are usually tinned or plated with something to prevent tarnish. Wire or circuit boards may or may not be plated. If there is any visible tarnish or corrosion, then scrape, sand, or scrub the surfaces gently until they're bright. Something as simple as a pencil eraser could be enough, or a knife blace or a little fine sandpaper. The exact method you use depends on common sense and the mechanical requirements of the situation. Leave your belt sander in the cabinet!!! Flux is the next step in getting clean surfaces. It is designed to dissolve the invisible oxide layer that inevitably forms on metal surfaces so that the soldering alloy can wet to the surfaces being joined for a strong mechanical and chemical joint. In metalworking you might use acid fluxes or borax or other chemicals. KEEP ALL SUCH FLUXES AWAY FROM ELECTRONICS WORK! The only safe kind of flux to use in electronics is rosin. Now, electronics folks have made it easy for you. Just buy rosin core electronics solder from any of the electronics suppliers. Since you're working with small stuff, small diameter solder is best. Something around .04 inches (1mm) is best. It takes very little heat to melt. Lastly, proper application of heat requires a reasonably sized soldering iron, an appropriately shaped and clean tip, and a firm understanding of what it is you're trying to accomplish... For small stuff like this you only need a 25W iron, and a small, slender tip. You'll probably find good suggestions for equipment for SMC use in the resources you dig up online. Take advantage of their experience. You *won't* be using a big honking 200W soldering gun or a metalworker's iron that's heated with a torch! Get a holder with a sponge in the base to put your iron in when it's not in your hand. You'll need the sponge and it'll protect the environment (and you) from accidental burns. If you want to go first class, get yourself a temperature controlled soldering station with all the bells and whistles. They heat up fast and can pour a lot of power into the job, but won't overheat the work. Expensive, but a real joy to have if you decide to get into the hobby long term. Now that we've got everything at hand, let's see what we have to do to make a good joint... Heat your soldering iron. When it's up to temperature melt a little solder on the tip. The flux from the solder will bubble up and smoke, and a small blob of solder should cling to the surface. Then wipe the tip with a quick swipe on the damp sponge. It should end up shiny. You'll do this anytime you pick up the hot iron and it isn't still shiny. Often another swipe on the sponge will bring it back. If not, another small touch of solder will be needed. Your soldering tip is now ready to apply to the joint. You've already made sure that the surfaces to be joined are shiny. You should also be sure that the mechanical joint between the parts is stable and reasonably strong. Using solder as "glue" to hold a joint together is not the best technique in general. It is susceptible to vibration and fatigue. With PC mount components you've got leads going through a hole to stablize things. With SMC you usually have the part glued to the substrate to keep it in place while it's being soldered. Joining wires, or wires to terminals, you'll wrap or twist or pinch the joint so it's mechanically sound before you solder. Finally, the big moment. Here's where you finally see what it is you're trying to accomplish. Apply your shiny, tinned soldering tip to the junction of the parts to be joined. Poke the solder into the joint near but not on the tip to see if the parts are hot enough to melt the solder. Remember: You are heating the PARTS hot enough so they will melt the solder, NOT heating the solder. Once the parts are hot enough, you'll see the rosin in the solder melt, spread, and bubble all over the joint followed almost immediately by the solder melting, flowing and wicking into all the crevises of the joint. Allow enough solder to melt into the joint to fill all the low points with a nice fillet. Remove the solder and iron and you should have a perfect joint, shiny and smooth. If the parts to be joined are of different weight, say a thin wire and a large terminal, you'll have to apply the iron more to the heavier part than the lighter one. Sometimes a tiny blob of fresh solder on the surface of the tip will help you to make a good thermal contact to the metal of the joint. These sort of subtleties will be obvious once you see and understand what's going on. The most important point is that you're heating the joint and the joint is what is heating the solder. Heat is applied, the flux melts, then the solder flows in after the flux. With a little practice you'll be able to easily make reliable joints with the minimum amount of heat and just the right quantity of solder. All the frustration usually stems from having the wrong equipment and materials, or else not understanding the basic process. You shouldn't have those problems if you do a little study and practice. You might want to buy some kind of inexpensive electronics kit to give you some experience with electronics components, PC board assembly and basic soldering. That, and you can end up with a useful or entertaining gadget when you're done. Hope that helps. Be well, Mike D. > Thanks Wayne. My previous "practices" though not numerous were > frustratingly poor quality and they were nothing like this in > difficulty. How about conductive epoxy solder? I went looking for some > around town and did not find any, but I know it exists. Would that be a > good alternative? Any drawbacks? [Mike Devour, Citizen, Patriot, Libertarian] [mdev...@eskimo.com ] [Speaking only for myself... ] -- The Silver List is a moderated forum for discussing Colloidal Silver. 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