Soldering tips for a newbie?

[33klfan]

I would like to solder some caps on a CB. Is there any valuable information i should know. I have a pretty decent solder gun and rosin core solder. Just not sure how you cleanly get the old cap off, plus how you heat the area for a nice solder of the new cap. Thanks.

[DrWho]

I would practice on something expendable before you start working on something you want to keep.

The important thing to keep in mind when soldering is to treat the iron as a heat application device...NOT a paintbrush. You'll have to let the solder touch the tip of the iron so that heat will transfer better, but you shouldn't attempt to guide the solder into place with the iron. The way solder works is it will 'flow' into areas that are metal and warm. The trick is getting both the circuit board trace and the component warm so that the solder flows to both. Soldering is one of those things where 3 hands would make it a lot easier...so investing in a nice clamp is probably a good idea if you plan to do a lot of soldering (not the goofy alligator clip things on a stand).

When removing components, the best thing to do would be to get a wick or a desoldering sucker tool thing. I prefer the wick, but some like the sucker. Either way, the idea is that you heat the solder so that it's melted and then you gotta remove the component before the solder dries. When you've got a wick handy, you can melt the solder and then it will flow into the wick - thus removing the solder from the board. The traces for the caps on the Chorus II crossover are probably close enough that you could heat both pins at the same time and not have to worry about removing any solder. In fact, I just did it last week in the lab (we wanna do some blind AB comparisons between all the various cap types).

[Marvel]

Great tips, Mike!

My best tip is this: When the iron rolls off the table... don't try to grab it...

[michael hurd]

If you are replacing a cap, cut the leads ( if you can ) and desolder with a braid or a vacuum device. It would be best to practice on some scrap PCB first to get a hang for it. Observe correct polarity ( unless it is a non polarized electolytic ), and slip the leads through the holes. Get the tip hot, clean it ( best is a sponge with water ) and tin the tip with solder. Apply heat quickly and apply the solder to the joint. It should flow out and have a shiny appearance, not like slushy ice.

You want to make sure the amount of time heating the joint is to a minimum. Higher wattage irons are better, it takes less time to heat the joint, therefore less chance of damaging the cap.

[SCOOTERDOG]

OMG! I had to laugh when I read this. I did not grab mine when I dropped it but I sure did jump out of the way...but not fast enough as it brushed my ankle and I had a burn there for a month.

[WMcD]

Well, he did say it was a gun.

Weller made some with one heat and others with two steps on the trigger. Either one will heat up pretty quickly. And you should only apply power through the trigger when you're ready. About 10 seconds or less will bring it up to temp.

The cleaning step for the tip can be done with a wet paper towel (when the tip is hot). If it is grungy, try some fine sandpaper. As others have said, getting a thin film of shiny solder on the tip is necessary. If you leave the heat on for too long the solder will start to oxidize and get gray. Then you have to clean again.

I do suggest safety glasses. I once "pronged" a wire and solder flew right in my eyeball. Ouch.

I use the bulb type sucker from RS. When hot the solder in the old joint is about as viscous as water and can be sucked off. The nylon, conical tip of the bulb may get plugged. All you do is let it cool and rap it against a flat surface. You can blow it out with the bulb.

You don't tell us whether you have a cap with wire leads which is going to a point to point type solder terminal. If so, cutting it about 0.25 inch from the terminal can help. Then you'll need a needle nose plyer to unwrap it while not disturbing the other wires going to the terminal. Then you will have to install the new lead.

You may, OTOH, have a through the circuit board type of device. Generally the same ideas are used. But over heating may cause the copper trace to pull away from the board. Then you've got problems.

In making any joint, there is consistent advice. You must heat the two surfaces so that they melt the solder. Therefore you have to get the chisle (sp) tip of the gun on both, and pull the trigger. Then apply the tip of the solder wire. The tip of the solder wire will melt and you feed in more 'til you have a nice shiny, smoking blob which stays there by capilary action. Then remove iron tip and solder wire.

In my experience, the smoking rosin is a good indicator. When the rosin burns off, the smoke stops, and this is the point where you are overheating the joint.

I bend the rule a bit. I get the solder wire just into that junction of the terminal and wire (or the two whatevers) and the iron probably melts it first. But that is to get the molten solder to thermally connect to the junction as quickly as possible. It is a bit of an art to get everything heated and the solder to flow, and get out before you overheat things.

Gil

I

[Rockets]

The first step is to throw out the "gun" and go buy a decent temperature controlled iron. I have a love/hate relationship with Weller. They're great when they work, but seem to crap out often in my experience. Use 63/37 rosin core solder. Clean, Clean and Clean again your compnents and tip. Wet your tip, wipe it and wet it again. Use heat sinks to protect componets, such as speaker tinsel leads, caps and resistors. Small alligator clips will often work when placed next to the component body...or next to the insulation on wire if you don't want the the insulation melting off the wire as you overheat and 'weld it'.

Most importantly, get on and then get the hell off what ever it is you are soldering/desoldering. Wicks and solder suckers are both great tools. If things aren't flowing, then you either didn't clean, are using the wrong temp setting, or need more flux. Unless you are really unlucky and have to deal with nickel coated wire. In which case a lot of profanity while cranking the iron up to MAX usually does the trick.

When using solder...less is more. The bigger the blob does not mean the better the job. Finally, never put away a tip "dry"

This is more than you'll ever want to know about soldering, but if you're bored and want to know how to do it right...

http://www.hq.nasa.gov/office/codeq/sldrbch1.pdf

http://www.hq.nasa.gov/office/codeq/solder.htm

There will be a written and practical test given at the end to test your proficiency....

.

[fini]

Soldering is one of those things where 3 hands would make it a lot easier...

Such as dating...

...so investing in a nice clamp is probably a good idea if you plan to do a lot of soldering (not the goofy alligator clip things on a stand).

What other types of clamps are there?  Seriously, you got a partsexpress part number, or something?

[WMcD]

This has been good reading.

I agree very much with Mike B. Experiment with some junk box item to gain some technique. Much of what is posted are war stories .

I see this as a general problem with hobby type projects. All of us have cherished hardware which we want to fix or modify, but we are inexperienced.

The telescope people have a bromide. If you want to grind a six-inch mirror, it will go more quickly if you grind a three-inch mirror first, to get experience.

Edit addition:

In the engineering world, there would be proof of concept and prototypes. Yet in the hobby world we have to do expert work, even though we have not done it before. That is why learning with a junk box project makes sense.

Gil

[DrWho]

Soldering is one of those things where 3 hands would make it a lot easier...

Such as dating...

...so investing in a nice clamp is probably a good idea if you plan to do a lot of soldering (not the goofy alligator clip things on a stand).

What other types of clamps are there? Seriously, you got a partsexpress part number, or something?

As far as "clamps" - I probably should have said "vise"....I use the Panavise 301 at work and the 381 in the lab:

http://www.westlake-electronic.com/store/search/1/search_sent/1/category/TOOL/SUBCAT/VISE/index.htm

[fini]

Mike,

It seems with a vise like those, you'd only be able to clamp one part (of two or more you're soldering together), unless the parts were the same thickness.  Can you tell me specifically how you use it (for what purpose)?  Do you use two at a time?

[DrWho]

I just use one vise to hold the larger of the pieces being soldered

together...it can be a PCB or connector or even just another wire.

Whatever it is, I use the vise to hold the piece such that I can apply

a lot of pressure from the iron without that piece moving around (which

is the problem with alligator clips).

I'll then hold the piece being soldered (or a pair of pliers holding

the piece) between the bottom side of my thumb and my ring/pinky

fingers so that the tip of my thumb and pointer/middle fingers are free

to hold the solder (you'll need to have a few inches of solder sticking

out so that it can reach where you need the solder joint to happen).

This frees up the right hand to apply the heat from the soldering iron.

You really don't need that much solder to create a good joint, but if

you need to apply more solder and run out of reach from your pointer

finger/thumb, then you can usually transition to holding the piece with

your middle finger while you rotate the wrist to get more solder

flowing. Once you have enough solder, you can just let go of it and

concentrate on holding the piece in place before you remove the iron.

The idea here is that you move quickly since leaving the iron applied

for long periods of time will start melting stuff (not to mention

making it too hot to hold). The entire process should take under a

second (including the wrist rotation) - if it takes longer, then chances are you don't have things

secured properly, or your tip is the wrong size, temp, or not tinned

properly, etc...

If I'm soldering a cap on a throughole PCB, then I'll usually put the

cap upside down in the vise and drop the PCB on top it. Or if you're

really lazy, you can bend the pins of whatever it is you're soldering

so that there is a mechanical connection holding everything together.

The vise is still nice for this because then you don't have to hold

anything except the solder and the iron.

When soldering connectors, I'll create a little jig that the connector

I'm soldering can plug into (so if I've got a male RCA tip that I'm

soldering to a cable, then I'll have a little board with a female RCA

jack mounted to it). I'll make the jig sit very low to the table so

that I can just have the wire laying on the table such that the wire

naturally sits inside the connector being soldered.

If the connector is brand new (as in no

solder present), then I'll stick the wire in and then push it down with

the iron before applying any solder. I'll then apply solder first to

the connector itself and wait for the heat to transfer through the wire

into the connector - at which point the solder will flow very quickly

into both the connector and the wire. I'll then drop the solder and

grab a pair of needle nose pliers to hold the wire before I remove the

iron and then wait for the solder to cool before letting go. It's nice

to have a jig setup so that you can push down on the connector without

the jig falling over (so you should have a board extending out

underneathe the connectors). It's also nice because it keeps solder

from dripping onto your bench.

If I'm reusing a connector, then there is most likely some solder still

on the connector. I'll heat it up and add more solder so that there is

a "puddle" for the wire to be inserted into. This is probably an easier

approach because you can just hold the wire with a pair of pliers the

entire time and don't have to worry about holding solder or burning

yourself. The only reason I don't use this approach when making a new

connector is that you don't need a huge puddle of solder for the

connection (and it makes it more annoying to fix the cable later on

when the cable breaks). You also have to be make sure you add new

solder so that there is flux available to improve the bonding to the

wire being inserted. Tinning the wire first is also good practice.

Have I bored anyone yet? I hope I don't come across proclaiming to be a

soldering expert...just sharing a few tips I've picked up from the old

guys at work. Everyone's hands work different so my philosophy is to

try everything and see what works best for me. It's nice for me because

at work I'm just fixing stuff that is already broken - so if I break it

further trying something new it's no big deal. The underlying concepts

seem to be the same for every approach though....find a way to keep

things from shifting while the heat and solder is being applied. I

personally like firmer grips on everything because the more pressure

you can apply with the iron, the faster the traces heat up - and

heating faster means less heat is transfered to the components

themselves (making them cold enough to hold without getting burned).

[fini]

Thanks for that great answer, Mike!  Just what I needed to hear!

[BEC]

Wow, all this fancy stuff you guys need for soldering.  Back in the day in the military all I needed for soldering was a Zippo lighter and the light provided by the rockets' red glare, the bombs bursting in air....

[DrWho]

Well the output of a Crown Macrotech can always be shorted if you're in a tight spot and don't have an iron handy...didn't believe it the first time I saw it, but it saved a show 2 months later.

[Blvdre]

Alright, I have to study that damn IPC 600 Soldering Standard Guide every year and here's what the ANSI standard says:

For typical PCB soldering, 700 F or there abouts is a good starting point. I wouldn't use a gun for pcb soldering, a smaller, cheap pencil iron would do the trick, a temp controlled station even beter. When de-soldering your cap, just add solder to the joint to make things flow (adding straight flux is the best method). Do this by putting your iron (clean, tinned tipped) on the pad, and add solder to the iron's tip. The solder will flow onto the joint. You can remove the solder by using solder-wick, a solder sucker, or a temp controlled de-soldering station (you bet I have one...). Frankly, solder wick takes too long and isn't all that effective. I would suggest a cheap spring loaded solder sucker. This step should be done as quickly as possible. If you're going to lift an etch or pad, it'll be at this stage. Then you'll be running repair wires, and no one wants that. Bend your new cap leads before putting through the board. The bends should be such that the cap drops straight down into the board. Be careful not to make the bends to close to the body of the cap or there won't be any strain relief for the cap. Now bend the leads flat against the board, making sure there is a little bit of space underneath the cap (so it's not resting on the board). Side note: There should always be a mechanical connection between the items you are soldering. Flip the board so it's component side down, so you have access the the underside of the board (always solder PCBs from the underside). Now rest your clean tip on the pad while applying solder to the tip. The solder will flow around the pad and up the lead, use as little solder as you can to accomplish this. Your dwell time should be about three seconds. Clip the leads and you're good to go. Absolutely practice on some wires or other solderables first to get a feel for things.

[colterphoto1]

...used to be able to rewire a Crown DC300 to put out 500 wpc using a Ding Dong wrapper....lol..jk

Thanks for your service to our country BEC! And all you veterans- Thank You!

M

[Groomlakearea51]

...go buy a decent temperature controlled iron. I have a love/hate relationship with Weller. They're great when they work, but seem to crap out often in my experience.

When using solder...less is more. The bigger the blob does not mean the better the job. Finally, never put away a tip "dry"

This is more than you'll ever want to know about soldering, but if you're bored and want to know how to do it right...

http://www.hq.nasa.gov/office/codeq/sldrbch1.pdf

http://www.hq.nasa.gov/office/codeq/solder.htm

There will be a written and practical test given at the end to test your proficiency....

Rockets: Great resource!!

I flunked soldering 101 many times before I got it right. My first caps replacement for a pair of Heresy crossovers looked like silver baseballs.... But I learned and now they look like silver golf balls... just kidding. I ended up buying a weller soldering 'station' from partsexpress and after practice and learning about some different tips, the solder "flows" like it's supposed to. Weller has a number of different tips available, and their instructions are also fairly good. Good point on safety glasses, sucker bulbs, etc. I pretty much limit myself to what I can do well and stay far away from PCB's, etc.

[JJkizak]

I always was mesmorized by the industrial soldering machines that soldered a huge board with a zillion connections in about 1 second. And it did a perfect job.

JJK

[Guest " "]

Try to time your soldering to exhales....you don't want to breathe the smoke from heated up rosin core or flux paste...small fan to blow away smoke even better.