Need some help with two soldering problems

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I have two problems that im facing right now while soldering.

Here is the first one:

I have many areas in my amp that look like that:
http://www.milkbands.co.il/potentiometer.jpg

In this photo you can see that the wire is kind of rolled on the area it
connects to and isn't soldered at all, i guess it's glued or something
because it doesn't move, although i can't see any glue.

I tried to add solder to it so it will have a better connection, but
i found out it doesn't work as easy as i thought.

The solder is forming small balls on the soldered area instead of spreading
nicely and covering the area.

Here is what i have done:
1. Applied flux to the area that needs to be soldered.
2. Applied solder to the tip of the iron.
3. Touched one of the pots leg with the iron to transfer heat.
4. Started adding solder by touching the area to be soldered with
with the solder wire.

I use a 63/37 solder and a 30w iron (which both are working perfectly
while soldering wires and components to the pcb.

Now, for the second problem:

Im trying to unsolder a big speaker terminal exactly like this one:
http://www.milkbands.co.il/terminal.jpg

I used a 60w soldering iron for this task as there is alot of solder that
goes deep into the terminal.

I used a mechanical solder pump (the one with the spring and the button
to pull the melted solder out.

The problem is that the soldering iron doesn't melt the solder so well,
only the area it touched and not deeper, and the solder pump almost
doesn't pull any solder (only very small bits). Mean while the terminal
gets super hot and im afraid it will melt the plastic housing it is sitting in.

Any suggestions?

Roi.
 
adding flux usually helps with desoldering work, even if it does not seem to be nescessary.
In your case it may help wetting the iron with solder and improve heat transfer to the terminal.
Your first image looks like wire wrap, if done properly with proper tools it doesn't need additional soldering.
regards
 
The problem is that the soldering iron doesn't melt the solder so well,
only the area it touched and not deeper, and the solder pump almost
doesn't pull any solder (only very small bits). Mean while the terminal
gets super hot and im afraid it will melt the plastic housing it is sitting in.

Any suggestions?

Roi.

Apply more fresh solder liberally. With persistence you should be able to get the existing solder to dissolve in the new solder. It may require repeated applications. The existing solder evidently has a high melting point.

w
 
Since your first question has been answered, I'll refer to your second.

Personally, I don't like "solder pumps" for desoldering. I use a Desoldering Iron/gun AND/or desoldering braid!

Soldering braid works especially well on old solder joints because most of the time, old joints have insufficient or NO flux present. Flux MUST be present to sucessfully remove/add/melt solder without using excessive temps! Solder braid (WITH flux) will essentially solve this dilemma.

You may also have a "bad"/worn tip! Try using a new one.

Some people prefer pumps and for those people, it works well BUT most people prefer to use braid OR better yet, a proper desoldering iron.


J-


PS: Solder will not flow in/around your joint UNLESS the joint is CLEAN!

ALWAYS clean any joint to be soldered OR desoldered with 99% alcohol regardless of whether it "looks" clean or not! You will be AMAZED at how easy proper preparation/cleaning will make your soldering job.
 
I use a desoldering station mostly. For manual desoldering I prefer the metal body spring pump type. And as much as I know many people swear by it, I absolutely HATE braid. Sorry Mr. Platinum.

If I encounter old solder, I just wet it with fresh solder. And a bottle of brush on flux is a good thing to have next to your iron anyway. I don;t like braid because I have to hold heat on the joint longer - long enough to heat through the braid AND heat the joint. And with just my iron tip and suction I can pinpoint the solder removal.


Hey, that is just my opinion, any method that gives reliable results for the individual using it, is a good method.
 
I use a desoldering station mostly. For manual desoldering I prefer the metal body spring pump type. And as much as I know many people swear by it, I absolutely HATE braid. Sorry Mr. Platinum.

If I encounter old solder, I just wet it with fresh solder. And a bottle of brush on flux is a good thing to have next to your iron anyway. I don;t like braid because I have to hold heat on the joint longer - long enough to heat through the braid AND heat the joint. And with just my iron tip and suction I can pinpoint the solder removal.


Hey, that is just my opinion, any method that gives reliable results for the individual using it, is a good method.

I find the brand 'Quick Braid' to be utter garbage while Solder Wick works well. For clearing through holes, I use a 'Soldapullt' with a Metcal STTC-126 tip that will actually fit into the hole which gets them as clean as new. Wick is better for cleaning off surface mount pads. After you use a Metcal you're not likely to put up with other soldering tools.

 
I use a desoldering station mostly. For manual desoldering I prefer the metal body spring pump type. And as much as I know many people swear by it, I absolutely HATE braid. Sorry Mr. Platinum.

NO Need to apologize! Like I stated in my earlier post, Some people like braid and some Don't! I personally own and use a complete Metcal rework station (MX-500) but I've been soldering for a long time and most people here don't need (or want) to spend hundreds of $$$ on soldering tools they'll only use a few times! The ORIGINAL question was submitted by someone who probably has a fairly inexpensive set up and just wants to know what "others" use successfully. Therefore, a dedicated DE-Soldering unit is probably impractical for him. GOOD desoldering takes a fair amount of practice!



If I encounter old solder, I just wet it with fresh solder. And a bottle of brush on flux is a good thing to have next to your iron anyway. I don;t like braid because I have to hold heat on the joint longer - long enough to heat through the braid AND heat the joint. And with just my iron tip and suction I can pinpoint the solder removal.

I NEVER apply MORE solder to a part I'm ULTIMATELY trying to remove. Solder Braid ACTUALLY acts as a heatsink (preventing the joint from dissipating too much heat to surrounding parts). BUT I ONLY recommend it for small jobs (one or two joints at a time). Adding more flux, (to the joint NOT the Iron) is also a possibility but again, most DIY'ers don't have OR NEED extra flux lying around!



Ultimately, a dedicated DEsoldering unit is the way to go IF you plan on desoldering a fair bit, but for the occasional joint here & there, Braid &/or Pumps CAN work well!


J-
 
Like Enzo, I often apply more solder. Sometimes the solder I am trying to remove just "feels" like it melts at too high a temp to be easily workable, even with extra flux applied. Mixing it with my 60/40 seems to lower the melting temp. I add solder, making sure it melts into the old solder, then suck it up with a basic spring loaded pump. Then I grab the braid and do the rest of the work. I have a cheap desoldering iron with a bulb pump (radio shack) but don't use it much.

I now also always use extra flux when desoldering. If the manufacturer did their job correctly, then all the original flux is cleaned off and gone, and of course, the solder will have oxidized like crazy since. You must use flux to remove the surface oxide and to help the solder to flow into the braid. I use a flux pen, not liquid or paste. I also give the braid a quick swipe of the flux pen just before using it, this makes the solder wick into the braid much more easily. I think that flux is your best friend when desoldering. I use it generously, not sparingly. I highly recommend DIYers to get a flux pen. They are cheap, very convenient, and will last your for years and years (as long as you put the cap back on tightly!).

That's my experience. As others have stated, everyone has different favorite tools and techniques for desoldering.
 
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