Clean up the tip of your soldering iron too.
From handle to tip, try angling about 45° so the the chisel tip gets right on the solder pad and resistor lead at the same time.

That helped.

 

Tun the temp down to 700°F and wipe the dip firmly (with rotation) across a damp sponge

Would it be okay to continue with the brass sponge?

 

I've increased the working temperature to 800 deg F. The solder tends to melt faster & I seem to be able to make more joints. But improvement doesn't mean there is possibly still something wrong.

I am beginning to wonder if your temperature isn't way off. 800 F is pretty toasty. I normally do fine using 600 F.

Would it be okay to continue with the brass sponge?

Yes, I have used wet sponge and brass sponge with good results. Six of one half dozen of the other. What diameter is the solder?

Ron

 

From the original post:

That's a mistake, sorry. Its a soldering iron, no gun.

 

Then gently push the solder onto the point where the iron touches the solder pad and iron tip.

Does this mean you are partially touching the tip with the solder? I feel this is relevant to what I may be doing wrong.

 

Would it be okay to continue with the brass sponge?

I strongly prefer the brass wool. Would’t call it a sponge, it doesn’t hold much water.

 

Does this mean you are partially touching the tip with the solder? I feel this is relevant to what I may be doing wrong.

Yes,
Try to
- hold the tip to the far side of the solder pad and press gently against the leg of the resistor coming up through the pad. The leg of the resistor should be very close to the tip of the iron and the tip itself should be on the copper ring of the solder pad.
Then
- feed you solder right where the soldering iron, and resistor leg and the solder pad meet.
(this is essentially below your soldering iron tip (because you are holding your iron about 45° angle.

also helpful, make sure to unwind about 6" of solder from your roll so you only have to fit the solder in the space, the roll of solder is too bulky if you don't unroll some.

 

picture in post #57 shows tip that is not clean and definitely not shiny.
here is an example of shine to expect from tip:

btw to solder means heat transfer is required and for conventional soldering iron that means making contact (and applying slight pressure). notice in above link that PCB is actually flexing a bit in previous link when contacted by iron. Force is comparable to writing with a ball pen. also notice that several joints look pretty bad. specially 3 and 4 are unacceptable.

here is one hopefully self-explanatory video of how solder should wet the iron. few tips:
a) iron should not be too hot because it will be impossible to keep it clean.
b) too cold is not good either as solder will fail to melt or solidify to quickly.
c) use flux. it help clean surfaces and wetting
d) be very careful and gentle with any mechanical cleaning that is high abrasion (see video below at about 9:55 for examples).
using low abrasion (back side of the scraping tool) is much more forgiving and one can apply some force but using anything that is sharp or abrasive need to be used very gently (ie. scraping with sharp blade in the direction of blade). if unsure, avoid high abrasion or pick softer materials.
e) wet sponge need to be wet but not dripping wet, squeeze it well before use to remove excess water or you will be placing high thermal shock on the tip. it could be piece of cloth too or metal "sponge" (brass etc.).

 

also wanted to point out that your soldering iron may be damaged. perhaps the ceramic of the heater element is broken, maybe the temperature sensor is not in contact with the tip or it is shorted. maybe it is not assembled correctly and not making contact etc. if in doubt try using lower temperature settings to find when the solder starts to melt then increase the setting slightly.

 

From the original post:

Also, from the original post: "I've got my iron on 480deg". And meanwhile, the OP mentioned the soldering iron in some other posts, and even showed some photos.

My curiosity is supported by the fact that Audioguru insists on this same behavior again and again. This is not the first time, nor the second, not even the third. Far from it, so that I've stopped counting. This kind of criticism and ranting, which is not even constructive, does not help anyone. I can give innumerable examples of such covert behavior. It is insidious and quite pernicious.

 

Also, from the original post: "I've got my iron on 480deg". And meanwhile, the OP mentioned the soldering iron in some other posts, and even showed some photos.

My curiosity is supported by the fact that Audioguru insists on this same behavior again and again. This is not the first time, nor the second, not even the third. Far from it, so that I've stopped counting. This kind of criticism and ranting, which is not even constructive, does not help anyone. I can give innumerable examples of such covert behavior. It is insidious and quite pernicious.

That's what make @Audioguru again posts so entertaining.

 

Some points about temperature…

The set point on a soldering station isn’t necessarily a reliable indicator of the temperature at the tip. In fact, there are many reasons why you should expect that is it only loosely coupled to the actual tip temperature.

First of all, there’s calibration. Unless you do calibrate the station using a specially designed thermometer, the numbers are as good as if they were a 1 to 10 scale. They don’t have any reason to bear more than a passing relationship to actual temperature, only hotter and colder in some range that soldering stations can get.

Second, even with some calibration, the technology of the iron can impact accuracy. The readout on the station may very accurately reflect the temperature of the heater but for older style irons that use a tip that slides over the heater, the thermal coupling can be very dodgy. Newer technology irons have integral heaters in the tips and so will be much more accurate.

Third is that while the temperature may even be close, there‘s no guarantee that it will stay that way. The moment the tip meets the work it is transferring heat to it and depending on the power of the heater and the thermal mass of the tip what started out at the ideal temperature can become cold quickly.

For this reason people sometimes turn up the heat on a lesser iron to higher than is strictly good. It can compensate to some extent for the loss of heat by being too hot at the start and the right temperature for a bit longer than otherwise.

The problem with a too-hot iron is two-fold. First, it can damage components and much more easily lift pads off the PCB. The temperature of the iron isn’t the problem directly, it is the temperature of the part that is getting the damage that’s the problem. So if you only heat the work for a short time, it will never exceed the safe temperature. The trouble is, you will heat the parts to the point of exceeding the safe temperature as soon as you have a little trouble with the joint, and you will because…

The biggest problem with a too-hot iron is burning the flux. If the iron is hot enough, the flux will burn before it is any good for the soldering, and it will leave a nasty gunk on the tip insulating it and making soldering even harder than if you’d had no flux to begin with. Burning flux makes more of a mess than just about anything else, and unlike the work which stands a chance if you can move quickly, the flux will burn almost immediately.

The right temperature for a given solder can be found in the solder’s datasheet. For Sn63/Pb37 with a rosin core, that will be somewhere around 350℃ (~660℉). If you have to make the tip actually hotter then that it probably means you are using the wrong tip and it doesn’t have sufficient thermal mass. In that case, don’t turn up the heat, change the tip.

 

I made only 2 posts with recommendations:
1) Hint: We use temperature-controlled soldering irons, not the uncontrolled soldering gun you said you use.
I am sorry that I mentioned the cheap sometimes fake and sometimes counterfeit products from "over there".
Hint; there are 2 other types of solder that we do not use for electronics.

2) Hint again: Do not look at what many people do wrongly on You Tube videos.

 

One more note,
Your solder spool says 0.8mm (about 20 AWG). This is quite thick for lead-free (tin) solder. The melting high temp means you need good heat transfer to the tip of the solder spool while minimizing conduction of heat up towards the spool. Using 0.40mm solder (38-gauge) makes it much easier to melt and flow the solder and flow where you want without getting blobs or bridging to other pads.

If you ever solder small SMD pads, you can find lead-free solder down to 0.15mm (34 AWG).

 

Some points about temperature…

The set point on a soldering station isn’t necessarily a reliable indicator of the temperature at the tip. In fact, there are many reasons why you should expect that is it only loosely coupled to the actual tip temperature.

First of all, there’s calibration. Unless you do calibrate the station using a specially designed thermometer, the numbers are as good as if they were a 1 to 10 scale. They don’t have any reason to bear more than a passing relationship to actual temperature, only hotter and colder in some range that soldering stations can get.

Second, even with some calibration, the technology of the iron can impact accuracy. The readout on the station may very accurately reflect the temperature of the heater but for older style irons that use a tip that slides over the heater, the thermal coupling can be very dodgy. Newer technology irons have integral heaters in the tips and so will be much more accurate.

Third is that while the temperature may even be close, there‘s no guarantee that it will stay that way. The moment the tip meets the work it is transferring heat to it and depending on the power of the heater and the thermal mass of the tip what started out at the ideal temperature can become cold quickly.

For this reason people sometimes turn up the heat on a lesser iron to higher than is strictly good. It can compensate to some extent for the loss of heat by being too hot at the start and the right temperature for a bit longer than otherwise.

The problem with a too-hot iron is two-fold. First, it can damage components and much more easily lift pads off the PCB. The temperature of the iron isn’t the problem directly, it is the temperature of the part that is getting the damage that’s the problem. So if you only heat the work for a short time, it will never exceed the safe temperature. The trouble is, you will heat the parts to the point of exceeding the safe temperature as soon as you have a little trouble with the joint, and you will because…

The biggest problem with a too-hot iron is burning the flux. If the iron is hot enough, the flux will burn before it is any good for the soldering, and it will leave a nasty gunk on the tip insulating it and making soldering even harder than if you’d had no flux to begin with. Burning flux makes more of a mess than just about anything else, and unlike the work which stands a chance if you can move quickly, the flux will burn almost immediately.

The right temperature for a given solder can be found in the solder’s datasheet. For Sn63/Pb37 with a rosin core, that will be somewhere around 350℃ (~660℉). If you have to make the tip actually hotter then that it probably means you are using the wrong tip and it doesn’t have sufficient thermal mass. In that case, don’t turn up the heat, change the tip.

Completely second that. That is sound advice.

 

I am beginning to wonder if your temperature isn't way off. 800 F is pretty toasty. I normally do fine using 600 F.


Yes, I have used wet sponge and brass sponge with good results. Six of one half dozen of the other. What diameter is the solder?

Ron

0.8mm

 

also wanted to point out that your soldering iron may be damaged. perhaps the ceramic of the heater element is broken, maybe the temperature sensor is not in contact with the tip or it is shorted. maybe it is not assembled correctly and not making contact etc. if in doubt try using lower temperature settings to find when the solder starts to melt then increase the setting slightly.

Would it make more sense to replace the whole unit or just the soldering iron?

 

I made only 2 posts with recommendations:
1) Hint: We use temperature-controlled soldering irons, not the uncontrolled soldering gun you said you use.
I am sorry that I mentioned the cheap sometimes fake and sometimes counterfeit products from "over there".
Hint; there are 2 other types of solder that we do not use for electronics.

2) Hint again: Do not look at what many people do wrongly on You Tube videos.

I believe I correct this: its a soldering iron not a gun. FYI

 

Some points about temperature…

The set point on a soldering station isn’t necessarily a reliable indicator of the temperature at the tip. In fact, there are many reasons why you should expect that is it only loosely coupled to the actual tip temperature.

First of all, there’s calibration. Unless you do calibrate the station using a specially designed thermometer, the numbers are as good as if they were a 1 to 10 scale. They don’t have any reason to bear more than a passing relationship to actual temperature, only hotter and colder in some range that soldering stations can get.

Second, even with some calibration, the technology of the iron can impact accuracy. The readout on the station may very accurately reflect the temperature of the heater but for older style irons that use a tip that slides over the heater, the thermal coupling can be very dodgy. Newer technology irons have integral heaters in the tips and so will be much more accurate.

Third is that while the temperature may even be close, there‘s no guarantee that it will stay that way. The moment the tip meets the work it is transferring heat to it and depending on the power of the heater and the thermal mass of the tip what started out at the ideal temperature can become cold quickly.

For this reason people sometimes turn up the heat on a lesser iron to higher than is strictly good. It can compensate to some extent for the loss of heat by being too hot at the start and the right temperature for a bit longer than otherwise.

The problem with a too-hot iron is two-fold. First, it can damage components and much more easily lift pads off the PCB. The temperature of the iron isn’t the problem directly, it is the temperature of the part that is getting the damage that’s the problem. So if you only heat the work for a short time, it will never exceed the safe temperature. The trouble is, you will heat the parts to the point of exceeding the safe temperature as soon as you have a little trouble with the joint, and you will because…

The biggest problem with a too-hot iron is burning the flux. If the iron is hot enough, the flux will burn before it is any good for the soldering, and it will leave a nasty gunk on the tip insulating it and making soldering even harder than if you’d had no flux to begin with. Burning flux makes more of a mess than just about anything else, and unlike the work which stands a chance if you can move quickly, the flux will burn almost immediately.

The right temperature for a given solder can be found in the solder’s datasheet. For Sn63/Pb37 with a rosin core, that will be somewhere around 350℃ (~660℉). If you have to make the tip actually hotter then that it probably means you are using the wrong tip and it doesn’t have sufficient thermal mass. In that case, don’t turn up the heat, change the tip.

Ill reduce the temp down to at least 680 after I try a different tip.

 

Ill reduce the temp down to at least 680 after I try a different tip.

Experiment with the temperature setting using Sn63/Pb37 rosin core solder.
Start at a low temperature such as 400°F (200°C) and apply the solder directly to the soldering tip.
Keep increasing the temperature by 50°F steps and find when the solder starts to melt.
You will probably find that it starts to melt before 450°F (230°C) while the recommended operating temperature is 700°F (370°C).

Use a damp sponge to clean the tip after each test.