Solder question.

Bobby Boggs · Post by **Bobby Boggs** » 10 Jan 2006 7:27 pm

Never soldered anything in my life.Hope I spelled it right.

I don't remember even watching anyone solder.Think it's time I learned.I thought I start with something easy like a volume pedal pot.

Anyone have time to walk me thru it? Starting with removing the wires from the old pot to soldering the wires to the new pot.I can handle removing the old pot.And installing the new one. I can even adjust the pedal the way I like. Just never soldered.I have and old solder iron and some wire someone gave me.Soon I'll be ready to build my own amp.

Thanks in advance.

Geoff Brown · Post by **Geoff Brown** » 11 Jan 2006 12:10 am

Just some basics here.

A 30 to 40 watt soldering iron should be fine for what you're doing. Higher wattage=higher heat. If you're ever working around pickups, keep with the 30-40 watt rule. Higher watt soldering irons and soldering guns can de-magnetize pups. Not a good thang

You can damage/destroy pots and other things with excessive heat, even from a 30-40 watter. You can also attach a heatsink between the area being soldered and the rest of the pot or whatever. Small alligator clips work well. This is not essential, but a good idea if you aren't experienced.

Keep your tip clean by having a wet sponge to wipe it on.

Keep it tinned by melting some solder on it. It should look nice and shiny, and will conduct heat well. A dull-looking tip won't, and you'll know it. Wipe off excess on the sponge.

Preheat surfaces to be soldered. If it's a lug on a pot, a couple seconds of contact will suffice. Pre-tinning the lug is a good idea. Just melt some solder on it. Not big gobs, just a small amount will do.

Tin your wire leads prior to soldering. Get a little solder on your iron and work it around the bare wire to coat it.

Now that you've tinned your wire and tinned your lug, hold the wire to the lug and apply the tip to solder them together.

A good solder joint should be shiny in appearance. A dull-looking joint indicates a "cold" connection. It may work, it may not.

Once you're satisfied with your work, trim any excess wire that could potentially contact something and cause a short.

I like the silver solder that RS sells in little tubes. Melts nice and comes in small diameters. I think it's nice to work with. YMMV.

I used to pay someone to solder in pickups and pots, and do wiring in my guitars. I finally got tired of spending my money that way and learned to do it myself. It's easy...you just have to do it a few times and get the hang of it.[This message was edited by Geoff Brown on 11 January 2006 at 12:15 AM.]

Jack Stoner · Post by **Jack Stoner** » 11 Jan 2006 3:28 am

There are probably some sites on the web that have soldering directions and maybe even pictures. Do a google search and see what you come up with.

You don't want to overheat everything but you want a good mechanical joint first then a good solder joint, not a "cold" solder joint.

And, ONLY use "Rosin" core solder - not the acid core type that is used on non-electrical applications.

James Marlowe · Post by **James Marlowe** » 11 Jan 2006 4:55 am

A good joint will end up shiney, and a cold one will appear dull.......james

Jim Sliff · Post by **Jim Sliff** » 11 Jan 2006 6:31 am

Also - for chassis grounds you need a 100-watt iron. A 440 will not heat the chassis enough for decent grounds. Some folks install tabs on the transformer bolts and solder to those, but they are prone to early failure.

On pots. make sure to sand a spott on the back prior to soldering. There's usually a coating or plating on them thhat makes it almost impossible to get a good joint.

Jerry Roller · Post by **Jerry Roller** » 11 Jan 2006 7:10 am

Oh yeah, and it looks cool and works well to touch your pinky or ring finger to your tongue for some moisture and touch it to the newly soldered connection to cool the solder before you let the wire move and ruin the connection. This is very important.
Jerry

Jack Stoner · Post by **Jack Stoner** » 11 Jan 2006 9:36 am

Jerry where did you come up with that? I've been in electronics since 1955 and never heard that.

I used to have a NASA Soldering Certificate and you wouldn't want to do that. Even in my Ham Radio days I never heard of that.

If you have a proper mechanical connection then you solder, make sure it doesn't move and let it cool on it's own.

Papa Joe Pollick · Post by **Papa Joe Pollick** » 11 Jan 2006 9:54 am

Why not just by-pass the moist finger thingy and kiss it?

Jim Sliff · Post by **Jim Sliff** » 11 Jan 2006 10:45 am

I think Jerry was kidding.

I HOPE Jerry was kidding.

Bobby Boggs · Post by **Bobby Boggs** » 11 Jan 2006 11:30 am

Maybe Jerry's mad at me??

Just kidding.I have no idea. I came here to learn.

A couple other questions. This old iron looks a little rusty are tarnished. Should I clean it with maybe steel wool before I start? I also found some Soder_Wick. Do I need this for this job?? I'm only changing out a Volume pedal pot.If not. What's it used for anyway?? Thanks for all the help guys...............bb

Dave Grafe · Post by **Dave Grafe** » 11 Jan 2006 12:02 pm

Don't use one of those big honkin' things that are for tin work, you need a little tiny point to do delicate electronics work.

The tip will most always look dull and rusty when it's cold, a major reason to pre-tin it before doing any work is to let the flux clean the oxidation off the tip - as mentioned above it aids in melting the solder and also goes a long way towards prolonging the life of the tip.

Lawrence Sullivan · Post by **Lawrence Sullivan** » 11 Jan 2006 12:08 pm

Bobby although I have soldered many things I am no authority but I'll attempt to answer a couple of your questions
A volume pot is a variable resistor, it controls the amount of current going through it and you can vary it manually
Yes you need to thouroughly clean the tip of the iron and then tin it by rubbing a small amount of solder on it
All wires or places to be soldered need to be cleaned by sanding or steel wooling or whatever method you choose
Use just enough heat and solder to get the job done so the solder flows between the two objects you want together

I suggest you practice a little on some scrap wires to get the hang of it
Feel free to email me at N9LS@Yahoo.com if you have further question I might be able to answer
Take your time, a good connection is critical for the proper operation of anything electrical
Good luck
Larry

Ray Minich · Post by **Ray Minich** » 11 Jan 2006 12:25 pm

The old story is that Bill Hewlett (of HP fame) had his newbies practise soldering, by assembling Heathkits, before they went on to build product.
Also check out the diameters of solder available. Rosin Core only. I try to buy the fine stuff too 'cause it works easier on the small pads on PCB's.
Whilst yer buying stuff, a good "solder sucker" is also a must, both for reworking old work and fixing mistakes.
And don't sling solder in the kitchen, it melts to the linoleum![This message was edited by Ray Minich on 11 January 2006 at 12:29 PM.]

Mike Ester · Post by **Mike Ester** » 11 Jan 2006 12:36 pm

I second Ray's advice about the solder. You only want to use resin-core solder on electronics. DO NOT use acid-core solder.

Jerry Roller · Post by **Jerry Roller** » 11 Jan 2006 12:38 pm

Jerry is not kidding. Maybe we are just ahead of our time over here in Arkansas.

That last remark was just kidding.
Jerry[This message was edited by Jerry Roller on 11 January 2006 at 12:39 PM.][This message was edited by Jerry Roller on 11 January 2006 at 12:40 PM.]

Stephen Gambrell · Post by **Stephen Gambrell** » 11 Jan 2006 5:16 pm

Bobby,
Bring the pedal down to Ware Shoals this weekend, I'll solder the pot in, and show you how---FOR FREE!!!

Bobby Boggs · Post by **Bobby Boggs** » 11 Jan 2006 5:36 pm

Thanks for the offer Steve. This weekends spoken for.Bless my heart.

I really wanted to try this on my own.But the old hands may be a little to shakey.I would probably do fine on a larger area like the hood of a 75 Cadillac.

Besides I can't even see a wire unless it's a big as a jumper cable.I may be ah calling......bb

Dave Grafe · Post by **Dave Grafe** » 12 Jan 2006 12:30 am

And don't sling solder in the kitchen, it melts to the linoleum

Don't try soldering while wearing shorts, either. Really.

David Mason · Post by **David Mason** » 12 Jan 2006 4:32 am

I'm not sure an anonymous, old, rusty soldering iron of unknown heat is even the absolute best thing to go with - I use an especially low-powered 25-watt Weller for cords and pots and stuff, there's no need for high power if you're just trying to make electrical connections. If you get all the wires positioned right, squashed down flat against what they're being soldered to, you're not trying to get the solder to do any mechanical load-bearing anyway. You can use little bits of tape, prop stuff up in pairs of pliers, dowels etc. to get everything positioned right BEFORE you start melting solder (W: tape burns).

The Weller SP23 and others have differently-shaped points available, I like to use both the pointy conical and chisel points for different things. They're like $12 or so at Ace Hardware, cheaper than blowing parts up with excess heat.

Michael Garnett · Post by **Michael Garnett** » 12 Jan 2006 9:39 am

My two cents worth of soldering tips-

Step one:

Buy a Hilton Pedal.

Step two:

Never worry about soldering a pot again.

Jim Bob Sedgwick · Post by **Jim Bob Sedgwick** » 12 Jan 2006 10:19 pm

Has anyone tried the new "cold solder" units that are selling on TV now? Supposedly they cool immediately after removing the tip off whatever you were soldering and won't burn you. Just an ignorant question from someone who does not know?

Jack Stoner · Post by **Jack Stoner** » 13 Jan 2006 3:35 am

A friend said his son, who is an "EE" bought one and they are not worth the effort. On very small joints they "might" work, but on something else, such as on a pot or a guitar cord plug, it's mostly "cold" solder joints.

I haven't tried one myself, just the report I got.

Steve Kaeser · Post by **Steve Kaeser** » 13 Jan 2006 11:18 am

In a previous life I managed a Radio shack or two, and that was in the day when everyone used soldering irons . . . . <g>

A number of good points have been made, as well as one test that I'm not inclined to try myself. Let me add a couple of points, but these should be considered in addition to other comments:

There is no great mystery about soldering a connection, in that you're really only melting metal on joint to make it permanent. To make a good connection the metal should be free of oils and other contaminants. Moisture isn’t really a problem, since that would evaporate, but some contaminants could result in a “cold solder joint”, which is the dull solder joint described earlier.

The question of what soldering iron to use is really dependant on the amount of space you have to work with, but a small 25 watt soldering iron as described earlier would be ideal. If you have one you want to use, make sure it fits into the space needed to touch the connection without hitting other things and you should be able to use a file to clean the tip off as needed. After it’s cleaned, put solder on it and make sure it’s properly coated and shiny.

Mount the potentiometer and then attach the wires mechanically and tighten them with pliers. They should not be able to move, even though they haven’t been soldered yet. If the move in the slightest (due to a table vibration or whatever) while the solder it hardening, then the solder joint will become dull and it will likely corrode and fail. (‘nuff said)

You’re now ready to solder, so make sure the soldering iron is hot enough to melt the solder and any heat sinks (alligator clips) are in place. When ready, touch the soldering iron to one of the joints to be soldered and then touch the solder to the metal on the joint (not the iron). When the iron heats the joint up enough to melt the solder, then it will suddenly start to melt and flow around the wires. Only put enough on to fill up the spaces between the wrapped wires, and then remove the iron and solder carefully, avoiding any movement of the joint. After 30 seconds or so, you should be able to touch it and it should also remain shiny. If the connection is dull, you can reheat it with the iron and let it cool again, but don’t add solder unless you have to.

You might want to practice soldering a good connection before you actually apply it to your project, but I’m not sure if you’re set up for that.

My 2-cents, anyway.

Steve Kaeser