I wouldn't worry as much about the diameter or making sure it's "eutectic" as Mr. Crowell does. The rest of the world gets excellent results with lead-free solders, as do I, and you can, too. I'll let you know if I see any tin whiskers show up.
For my own part, I think Mr. Crowell focuses far too much on the solder and far to little on the equipment and the preparation. While you can (as I did) do excellent work with the kind of cheap crap you could buy at Radio Shack in the late 70's, if you value your time at all, it's worth getting good stuff, but I'm getting ahead of myself. There are three rules for getting good solder joints. The materials to be joined must be clean, they must be fluxed, and they must be hot. The material that is normally soldered is copper, but just about any pure metal is going to oxidize when it hits air. For those PC boards that have been sitting around in that ziploc bag for several years, you may not be able to see it, but all those copper bits are covered with a thin layer of tarnish. Solder will not wet tarnish. Now, flux will deal with a little bit of tarnish, that's what it's for, but a lot needs to be cleaned. Get yourself some Scotch Brite(tm) and get to work! You can (and probably should--I do) buy flux core solder, but it is often handy to have extra flux lying around, so get yourself a bottle of liquid flux. As Mr. Crowell says, only use rosin flux (acid flux corrodes a lot faster) but remember that you should clean the flux off once you're done. If you've ever read that you can't carry melted solder on a soldering iron because it won't work, the reason it won't work is that the flux in the solder boils off. Applying flux directly to the work piece makes that technique work. (It's how surface-mount stuff is done with an iron.) As far as getting it hot, well, that's where the iron comes in. The kind of iron you want depends on the kind of soldering you're doing. Putting together some kits? Get yourself a temperature controlled iron and set the temperature to whatever the solder manufacturer recommends. You don't want it too hot because the adhesive that holds the traces to the board can melt and traces can lift and nobody wants that. I've heard good things about the Hakko FX-888D, and it's under $100 from Amazon. While you're at it, get some liquid flux and one of those hand desoldering pumps. Get too much solder on the joint? (And you will!) You can heat the joint and suck the excess away. They're cheap. You might also want to get some desoldering braid. I don't use it, myself, but some people like it. If you want to do surface mount, you'll need a setup that's different. I know guys who do reflow soldering with toaster ovens or hotplates and embossing guns, but I have an Aoyue 968. I solder with the iron and desolder with the hot air. Works a treat. Dealing with surface mount is not hard but it's different from what most hams are used to, so you should probably seek specific advice on how to do it if that's what you want to do. If you're soldering PL-259's onto coax, you don't want anything like that. For that, I have a 75-watt uncontrolled iron that's intended for soldering stained glass windows. I use that because it has a honking big chunk of copper at the tip. When you heat the soldering iron, the iron itself gets hot, and when you apply it to the joint to be soldered, heat starts flowing from the iron tip into the joint. Now, that causes a lot of things to happen, most of them bad. The iron drops in temperature and the copper of what you're soldering starts to oxidize. The insulation that's near the copper starts to heat and may melt. When you're heating coax, you want the heat to flow into the coax connector as quickly as possible to minimize the melting of the insulation. Since a coax connector is a fairly large thermal mass, you need a large thermal mass to heat it quickly. You always want what you're soldering to heat quickly. If you're soldering components to a board, they've got specified times and temperatures you can apply soldering irons to them before they get damaged. It's usually like 10 seconds for like 500C. Now, 10 seconds is longer than it sounds when you're trying to get the iron, the solder, the component, and the board all together where you can get the work done, but it is possible to damage components by overheating. So, I recommend using the largest soldering iron tip that will work comfortably with what you're working on and I like chisel tips rather than conical because there's more area for heat transfer. I basically have three chisel tips that I switch out depending on what I'm doing. I have a tiny one for surface mount, a medium sized one for putting through-hole components on boards, and a larger one that I think makes it easier to solder to ground planes like for "ugly" construction. Now, that's what I think is important about soldering. Note that you can follow Mr. Crowell's advice and mine simultaneously. Maybe you even should. I don't know. I do know it's one opinion, worth what you paid for it. On Fri, Aug 12, 2016 at 04:45:39PM -0500, JP Pritchard via BVARC wrote: > Great article. I'm on Amazon and I don't see eutectic diameter .46mm. What > brand sells that size? > > JP > KG3JPP > > > > _____ > > From: BVARC [mailto:[email protected]] On Behalf Of Rick Hiller via > BVARC > Sent: Friday, August 12, 2016 4:30 PM > To: BRAZOS VALLEY AMATEUR RADIO CLUB > Cc: Rick Hiller; Bill Crowell, N4HPG > Subject: Re: [BVARC] When all you really want is JUST A DROP! > > > Iron wattage, temperature, tip shape, proper method, etc. also play a big > part in getting good joints. And......Practice, practice, practice!!!! > > Sent from my eye doo hickey > > On Aug 12, 2016, at 2:00 PM, Bill Crowell, N4HPG via BVARC <[email protected]> > wrote: > > > > All, > > Hand soldering is very much an art form. I was pretty good at it, but have > been learning over the years. I have learned a lot from Brian, KF4VOO as > well as watching NASA training videos on YouTube and from other sources. > These topics I've discussed on the air, but putting them in writing for the > rest of the class <grin>. > > Let me give these out as a series of points: > 1. Use Eutectic solder - 63/37. That's 63% tin and 37%lead. Eutectic means > that both components melt/freeze at the same temperature. This is extremely > important for hand-soldering. 60/40 is easier to manufacture, but gives > poorer results because it was also designed for flow soldering. None of that > lead-free crap. My XYL, Dasha is an environmental engineer (and a licensed > Professional Engineer in the State of TEXAS). She's not worried about lead > contamination from our soldering leaching into the ground water and killing > kittens and puppies and that's good enough for me. > > 2. The flux should be rosin core. Period. > > 3. The diameter should be skinny. 0.46mm - the reason is that we don't want > too much solder in the joint. > > And for today's topic: Flux. > > In an ideal solder joint, there should just be the proper fillet of solder > where the junction is formed. Those of you who are welders understand > fillets. > > The amount of flux inside even the best solder tends to cause the operator > to apply too much solder to the joint. The internal flux dissipates before > the heat-bridge gets the solder flowed. > > The answer - add flux to the joint. I suggest liquid flux where the rosin is > dissolved in alcohol. > > I got some good flux from Fry's and picked up a Weller squeeze bottle with a > needle in it. This dispenser SUCKS. Flux all over the work and the bench. A > waste of money and time in cleaning. Liquid flux is sticky until completely > dried out. > > The solution to the problem with the SOLUTION was to get a really good > bottle+cap+dispensing needle. I found a deal on Amazon linked here: > > https://www.amazon.com/gp/product/B01G2QZQG8/ref=oh_aui_detailpage_o00_s00?i > e=UTF8 > <https://www.amazon.com/gp/product/B01G2QZQG8/ref=oh_aui_detailpage_o00_s00? > ie=UTF8&psc=1> &psc=1 > > This kit is for "Vape" - whatever that is. It's an inexpensive kit of > various bottles and dispensing needles. The needles are for syringes, but > not for the pokey kind - just a blunt tip. > > In the bottle with yellow cap and yellow needle is the flux. It's all happy > and drips out just the right amount. The black is even finer and filled with > lubricating oil for my guns. I'll use the other bottles and sizes for > various glues and such. > <IMG_0522.jpg> > > Here's a link to the flux I got at Fry's, but available on Amazon: > > https://www.amazon.com/MG-Chemicals-8351-125ML-Halogen-Bottle/dp/B00S16UAGE/ > ref=sr_1_4?s=industrial > <https://www.amazon.com/MG-Chemicals-8351-125ML-Halogen-Bottle/dp/B00S16UAGE > /ref=sr_1_4?s=industrial&ie=UTF8&qid=1471028240&sr=1-4&keywords=liquid+flux> > &ie=UTF8&qid=1471028240&sr=1-4&keywords=liquid+flux > > Just a drop or 2 makes a big difference. Keeping 100 drops OFF the bench > makes it funner. > > 73 > > Bill Crowell, N4HPG > Pearland, TX > [email protected] > I prefer to live a life of galvanic isolation. > > > _______________________________________________ > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org > > > _______________________________________________ > BVARC mailing list > [email protected] > http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org _______________________________________________ BVARC mailing list [email protected] http://mail.bvarc.org/mailman/listinfo/bvarc_bvarc.org
