Welding is not in my skill set, though I can appreciate some nice welding. We used to purchase lots of welded parts, lots of it was aluminum.
Finally writing a book on soldering
- Thread starter dreadnut
- Start date
Rambozo96
Senior Member
Any advice desoldering double sided PCB? At the moment that seems to be my weakness as the time I’m done the pads get kinda crinkled up or flat out get burned off. On the single sided stuff I can desolder an IC fairly quickly and efficiently with minimal to no evidence on the pads. This double sided stuff however is tricky to me.
What are you using for de-soldering, copper braid, mechanical solder-sucker or? I always used a PACE kit but that's a bit out of most peoples' price range for hobby work.
I actually prefer the copper braid. Soak it with flux. Flux both sides of the pcb. Put the pcb in a holder so it is standing up, then you don't have to overcome the additional force of gravity to pull the solder out of the hole, and you can watch both sides as you perform the operation. Try to move the component lead back & forth lightly with the soldering iron during the operation; this will help keep "sweat joints" from occurring where the component legs are in contact with the plated through holes. Never put any mechanical pressure from the soldering iron tip on the pads. Put a tiny drop of solder on your iron to to enhance the melting process, and all the solder from both sides should soak into the copper braid within 3 seconds. If it takes any longer than that, your heat capacity is insufficient. With a multi-leaded IC in particular, skip around to different pins so you don't build up the heat too much in one area of the board.
I actually prefer the copper braid. Soak it with flux. Flux both sides of the pcb. Put the pcb in a holder so it is standing up, then you don't have to overcome the additional force of gravity to pull the solder out of the hole, and you can watch both sides as you perform the operation. Try to move the component lead back & forth lightly with the soldering iron during the operation; this will help keep "sweat joints" from occurring where the component legs are in contact with the plated through holes. Never put any mechanical pressure from the soldering iron tip on the pads. Put a tiny drop of solder on your iron to to enhance the melting process, and all the solder from both sides should soak into the copper braid within 3 seconds. If it takes any longer than that, your heat capacity is insufficient. With a multi-leaded IC in particular, skip around to different pins so you don't build up the heat too much in one area of the board.
DThomasC
Senior Member
I assume you're replacing a component? Something that seems obvious once you've been told: cut all of the leads and remove the body of the component first. Then you can remove the leads one at a time. After that, use copper braid as Dread said to remove the solder from the holes.
SFIV1967
Venerated Member
Yeah, they had us using PACE Kits way back in '72 in the Navy. Best to do it all in one continuous operation.
jp
Senior Member
So Dread, can I exploit your expertise to get some soldering gear advice?
I once responded to a craigslist ad in which a company was selling off a bunch of old Metcal MX-500P soldering stations. I ended up scoring one for $50 with a huge assortment of tips and enough solder to last me two lifetimes. I'm aware that even used, this setup costs way more than a standard temp-adjustable Weller soldering station, and I'm guessing the Metcal is more for professional detailed PCB SMT work.
I've used it successfully for misc. projects, mostly amp, guitar stuff, and assorted electronic stuff. I've also used it for basic household projects too, and it's worked just fine. It automatically heats up quickly to just the temp I need, and although I still use alligator clips for heat sinks on sensitive components, I've never felt ramp up too hot to burn out anything.
My question is . . . since I'm pretty ignorant about high-end soldering gear, I often wonder whether this is the perfect example of overkill. Is this the equivalent of using professional Snap-On tools to assemble an IKEA shelf? Would I be better off with a more utilitarian Weller station, or should I consider myself lucky and keep this setup?
I once responded to a craigslist ad in which a company was selling off a bunch of old Metcal MX-500P soldering stations. I ended up scoring one for $50 with a huge assortment of tips and enough solder to last me two lifetimes. I'm aware that even used, this setup costs way more than a standard temp-adjustable Weller soldering station, and I'm guessing the Metcal is more for professional detailed PCB SMT work.
I've used it successfully for misc. projects, mostly amp, guitar stuff, and assorted electronic stuff. I've also used it for basic household projects too, and it's worked just fine. It automatically heats up quickly to just the temp I need, and although I still use alligator clips for heat sinks on sensitive components, I've never felt ramp up too hot to burn out anything.
My question is . . . since I'm pretty ignorant about high-end soldering gear, I often wonder whether this is the perfect example of overkill. Is this the equivalent of using professional Snap-On tools to assemble an IKEA shelf? Would I be better off with a more utilitarian Weller station, or should I consider myself lucky and keep this setup?
Nuuska
Enlightened Member
Hello
I have a Weller since forever - and few years ago I got an older Metcal dual probe kit for free along with some PACE desoldering stuff.
First I was wondering about the idea of having a switch between those to probes, but soon learned, that it heats up so quickly, that by the time you have taken it off the holder and pointed towards target it is hot. Just love it.
But this is only from an amateur - eagerly waiting for DREADNUT to tell us more.
I have a Weller since forever - and few years ago I got an older Metcal dual probe kit for free along with some PACE desoldering stuff.
First I was wondering about the idea of having a switch between those to probes, but soon learned, that it heats up so quickly, that by the time you have taken it off the holder and pointed towards target it is hot. Just love it.
But this is only from an amateur - eagerly waiting for DREADNUT to tell us more.
Well jp, you got a great deal on that Metcal soldering station! That is a fine tool for working on all kinds of electronics.
It's a good thing that you got a big variety of tips along with it, because half the battle is matching the mass of the tip to the mass of the workpiece. Small solder joint, small tip, etc.
Also, solder melts in the 450F range, so the maximum temp your iron should ever be set at for electronics soldering is 650F.
As always, the soldering operation should not take more than 3 seconds - any longer, and you're not transferring enough heat into the workpiece for some reason.
It's also worthwhile to check continuity between the tip of the iron and the ground prong on the AC cord to help eliminate static charges and voltage spikes. For example, it's not good to have a table saw operating on the same AC circuit as your soldering station; major voltage spikes.
Heat causes oxidation, so if you don't read continuity, there is probably excess oxidation between the tip and the heating element.
Heat oxidation is also why you should coat the tip with solder whenever the iron is idling at 650F in the holder, so the oxidation forms on the solder instead of the tip.
It's a good thing that you got a big variety of tips along with it, because half the battle is matching the mass of the tip to the mass of the workpiece. Small solder joint, small tip, etc.
Also, solder melts in the 450F range, so the maximum temp your iron should ever be set at for electronics soldering is 650F.
As always, the soldering operation should not take more than 3 seconds - any longer, and you're not transferring enough heat into the workpiece for some reason.
It's also worthwhile to check continuity between the tip of the iron and the ground prong on the AC cord to help eliminate static charges and voltage spikes. For example, it's not good to have a table saw operating on the same AC circuit as your soldering station; major voltage spikes.
Heat causes oxidation, so if you don't read continuity, there is probably excess oxidation between the tip and the heating element.
Heat oxidation is also why you should coat the tip with solder whenever the iron is idling at 650F in the holder, so the oxidation forms on the solder instead of the tip.
Nuuska, 25 years ago I took about 15 PACE SMT stations to Europe and did training sessions with our Service centers including Denmark, Sweden, and Norway.
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jp
Senior Member
Thanks, Dread!
Your response was a relief. Like Nuuska, I do love this setup, especially because it heats up so quickly. I also appreciate the great advice and tips for upkeep. When your book comes out, I'll definitely buy a copy!
The condition of the old gear is kinda rough, but like a dependable old truck, it works every time, and I'm happy with it. Thanks again!
Also, I'll never use it like the woman above. I like my hands. :C)
Haha, "How Not To Do It." They obviously shot this scene with a cold iron!
I had to solder some fairly substantial tin-plated parts using a Turner Tornado torch. Turned it off, set it back on the bench. Less than a minute later, I discovered I needed it again. So where do you suppose I grabbed it? That's right, by the nozzle. I heard the flesh sizzling and saw the smoke before I felt the pain, LOL.
Guildedagain
Enlightened Member
Soldering is always a challenge. It helps to have really good solder like the Kester stuff I bought @ Radar electric decades ago.
Sponges, natural sponges only for me.
It helps to score an old Weller station and I finally did.
Otherwise my Weller butane does the job quite well and heatshrinks, but the hot gas blast is something to be weary of while working, easy to fry other wires. I also have a Wall Lenk trigger style solder gun with light. I reach for this one when unsoldering wires from the back of pots. It will melt solder 3 seconds from pulling the trigger from cold.
Here was a challenging job replacing one of the transistor in an old fire truck PA/Siren unit that lost almost all power.
Sponges, natural sponges only for me.
It helps to score an old Weller station and I finally did.
Otherwise my Weller butane does the job quite well and heatshrinks, but the hot gas blast is something to be weary of while working, easy to fry other wires. I also have a Wall Lenk trigger style solder gun with light. I reach for this one when unsoldering wires from the back of pots. It will melt solder 3 seconds from pulling the trigger from cold.
Here was a challenging job replacing one of the transistor in an old fire truck PA/Siren unit that lost almost all power.
Looks like you did a fine job on that.
Guildedagain
Enlightened Member
Thx. I'd not be able to sleep right if I get a cold solder joint. A solder job is a reflection of your self. Do you take pride in your work?
The Kester solder is really thin and really excellent for electronics. I believe it might be real lead or have more of it than this modern stuff?
I have this system of marking a pair of blue nitrile gloves SOLDER so that I won't were them the other way around and I like to handle solder with gloves on if I can.
Then there's the fumes, a bit annoying and not good to breathe although I've done 100 solder jobs right in the house before... but I try to not do it near the kitchen.
One time for a bigger job, I rigged up a vac over the work to pull fumes, that was genius.
I weld also, and arc welding can really put out some toxic smoke. You almost need a vented hood at that point but I do all my work outdoors so that usually takes care of it.
I don't use a paste flux, really almost never have.
I use a powdered flux for brazing with bronze wire, that's a must, but I'm not sure there's anything to gain by using paste flux with modern solders?
Here's my Weller Portasol from when I fixed the D25 9V battery pigtail the other day, with heatshrink attachment installed. bought it new 25 years ago, made in Ireland.
Been on countless service truck repairs. Most people don't understand the importance of solder/heatshrink in vehicular situations. Rider Truck who I worked for at the time insisted on every electrical repair soldered and heatshrinked, especially on semi truck and trailer lights.
Notice the clever owner added OFF setting, that's the gas on/off. The throttle is in the back, rotary. This thing can get real hot, way too hot if not careful. I let it idle all the way down so the tip doesn't overheat while fiddling with the wires, then bring it up to solder. 99% of a solder joint is the condition of the tip of the soldering iron.
I also have some of the giant wooden handled plumbers I suppose soldering tools that you would heat with a torch.
The Kester solder is really thin and really excellent for electronics. I believe it might be real lead or have more of it than this modern stuff?
I have this system of marking a pair of blue nitrile gloves SOLDER so that I won't were them the other way around and I like to handle solder with gloves on if I can.
Then there's the fumes, a bit annoying and not good to breathe although I've done 100 solder jobs right in the house before... but I try to not do it near the kitchen.
One time for a bigger job, I rigged up a vac over the work to pull fumes, that was genius.
I weld also, and arc welding can really put out some toxic smoke. You almost need a vented hood at that point but I do all my work outdoors so that usually takes care of it.
I don't use a paste flux, really almost never have.
I use a powdered flux for brazing with bronze wire, that's a must, but I'm not sure there's anything to gain by using paste flux with modern solders?
Here's my Weller Portasol from when I fixed the D25 9V battery pigtail the other day, with heatshrink attachment installed. bought it new 25 years ago, made in Ireland.
Been on countless service truck repairs. Most people don't understand the importance of solder/heatshrink in vehicular situations. Rider Truck who I worked for at the time insisted on every electrical repair soldered and heatshrinked, especially on semi truck and trailer lights.
Notice the clever owner added OFF setting, that's the gas on/off. The throttle is in the back, rotary. This thing can get real hot, way too hot if not careful. I let it idle all the way down so the tip doesn't overheat while fiddling with the wires, then bring it up to solder. 99% of a solder joint is the condition of the tip of the soldering iron.
I also have some of the giant wooden handled plumbers I suppose soldering tools that you would heat with a torch.