soldering issues

[K-MAN]

I'm finishing up my new pc board for my amp and even though I've been soldering for awhile I keep running into the problem of not getting good wetting. I'm not sure if the soldering iron is too hot or cold but after I tin the tip it starts getting blackish quickly and doesnt conduct heat very well to my joint. As a result it takes a bit longer to heat the joint properly and sometimes causes it to get too hot. Could it be the temp or so I try switching to another solder like 63/37 instead of the regular 60/40 rosin core stuff I use.

[Shannon Parks]

What brand solder and iron do you use? The good stuff makes a huge, huge difference.

[dcriner]

If you have a variac, you can use it to vary the iron's temperature. But, too much heat can delaminate a PCB's trace.

I use Kester "44" 60-40 solder, and it seems to work OK, even though my soldering skills are not all that great. I have tried the eutectic 63-37 alloy, and do not like it as well as 60-40.

What diameter solder are you using? For point-to-point wiring, I use 0.050" -- but for PCB work, a finer size is called for. Are the PCB's traces tinned? That helps.

Kester's website claims that the resin flux can deteriorate after the solder is a year or two old. I haven't noticed this, though.

Maybe replace the tip?

[K-MAN]

I just use a generic 60/40 rosin solder from my electronics store. What wattage irons do you guys use? I have a 40watt but it didn't seem to get hot enough so I've been using my weller butane iron. What do you guys do as far as tinning, do you apply solder to the tip then wipe it or vice versa? Is it damaging to wipe the tip too often?

[dcriner]

If a 40-W iron isn't getting hot enough to solder a PCB, I fear there is something wrong with the iron.

Actually, for a PCB, 40W is a little large. I use a 25-W RadioShack pencil-type iron for PCBs.

For point-to-point wiring, I use a Weller 8200, dual 100/140W gun. (Pull the trigger half-way, and you get 100W; pull it all the way for 140W.) Your 40-W iron would be pretty wimpy for point-to-point.

I think you need two different irons - one for PCBs and one for point-to-point wiring.

I keep a moist rag or sponge available, and wipe the tip whenever it needs it.

[mesherm]

If your iron tip is getting "black" and oxidizing too quickly it definitely is too hot which as you found out is just as bad as too cold. As dcriner stated you probably should use a 25 watt iron for PCB work or use a variable temp iron. A 25 watt will usually work for most point to point work too.
Save the 40 watt iron for the heavy duty stuff. BTW on PWBs with ground planes or large copper foil areas, even a 25 watt iron will stagger a bit. Those ground plane holes can be giant heat sinks.
The best tip cleaners are the ones with brass "Brillo" pads in a holder.
If your iron has oxidized too badly you will have to scrape it with a razor blade and quickly re-tin it. A clean tip is absolutley essential to good soldering.

[Ty_Bower]

I've got a couple of 25 watt Radio Shack $4.99 specials. They're too hot for soldering most light duty electronics and circuit boards, but I use them anyway. They'll definitely lift the traces on the lesser quality boards.

When the tips get too beat up, I'll grind a new end using a flat file. I grind two flats on opposite sides to make a chisel point. I basically try to get something that looks like this: V

After grinding it with the flat file, the Radio Shack tips will be copper colored. Plug it in and heat it up, and immediately apply some solder as soon as it is hot enough to melt. Then I usually wipe the tip on a wet piece of folded up paper towel before I make each solder joint. I don't think you can wipe it too much. You're basically just taking of the slag that forms on the tip. I can't imagine it would be possible to wipe of the layer of solder that's stuck to the copper tip.

Wipe it off when you are done, before you unplug the iron. I find that if I don't keep the tip clean, then small black spots will form. If I let it go on too long, the spots get bigger. Then it is time to grind it down again. Of course, you can only grind the end so many times before there's nothing left. Then you need another $4.99 special at the 'Shack.

[dcriner]

I find that if I don't keep the tip clean, then small black spots will form. If I let it go on too long, the spots get bigger. Then it is time to grind it down again. Of course, you can only grind the end so many times before there's nothing left. Then you need another $4.99 special at the 'Shack.

Ty, my 25-W iron from RadioShack has a replaceable tip - just loosen the setscrew, and remove the tip. RS used to sell replacement tips, but it's been a while since I've bought any.

I have also been able to purchase replacement tips for my Weller 8200 gun at RS.

[crispycircuit]

Dirty grungy soldering tips clean up fast with your electric wire wheel/grinder. File or grind the tip to proper shape and retin it. But for working on old vintage amps, you need a Weller 100/140 gun to get repairs done with that old brittle solder. Also to use a solder sucker effectively the Weller gun heats high enough to get the old brittle solder to flow. So you really need both a gun and pencil iron. And use a large damp sponge to wipe your tip before soldering. Hemostats work wonders for heat sinks, tight areas, and make it easier to make nice looking repairs.....

[dhuebert]

The rule is: Don't buy a tool until you need it and then buy the best one you can possibly afford.

Stop pissing around with Rat Shack crap and buy one of these:

http://www.cooperhandtools.com/brands/C ... 7103001146

I guarantee you will not be dissappointed. Stainless steel tip means no filing ever again. 60 watts means lots of power for those ground plains and temperature control means no lifted traces. period.

Don

[TomMcNally]

Well put Don ...

I bought a new Weller WTCPT last year to replace my
20 year old one that had THE SAME TIP for the whole
time ... and went through at least 6 pounds of solder.

You can't beat them ...

Actually, even a Weller temperature controlled stand alone
iron will do a nice job and last a long time.

[K-MAN]

I solved my soldering problem and got some Kester44 63/37 solder which is supposed to have stronger flux than the regular stuff and it seems to work great.

[paart]

Yeh, I love the Weller WTCPT that my wife bought me for Father's day about 4 years ago. There are a lot of different shape tips available for it in 3 heat ranges. It's made soldering a joy!

Just a note about cleaning tips: Don't use a wire brush or grinding wheel on an iron-plated tip, as the plating is thin, and you'll remove it. In which case, you'll then have a copper tip. It you have a copper tip, it doesn't matter since they don't last very long, anyway! If the tip is kept properly tinned, simply wiping it on a wet soldering sponge (a wet paper towel will do in a pinch), should keep the tip clean.

[TerrySmith]

I've got a Weller WTCPL that was my dads iron. It doesn't seem to get hot enough. How do I know what temp tip I have? The handle part looks like the newer WTCPT.

The 50w Ungar iron I got when I was a kid eats up tips like crazy.

[TerrySmith]

It seems I have a 600 degree tip, has a "6" stamped on the bottom. HMCelectronics.com has new WTCPT stations for $119.00 (cheap!) and various tips for $3.00. I ordered several different ones to try, and a new barrel nut, mine's corroded slightly.