OK I just went over to radio shack on my lunch and grabbed these 2 solders. Which one is going to be best.

One is a 62% tin / 36% lead / 2% silver solder and the other is Lead free so its just 96% tin / 4% silver. That was all they had for silver solder. Which one of these is going to be better?
Does not having lead make it stronger? Higher Melt temp?

http://www.radioshack.com/product/in...entPage=search

http://www.radioshack.com/product/in...entPage=search

I also picked up a solder sucker deslodering tool. I'm going to remove all of the old solder that I put on and resolder it all with whichever of these silver solders is bettter.

I have the tin/lead/silver stuff and it's worked well for me. I'm going to have to try some of the tin/silver stuff. I just wonder how well it flows and how its makeup will affect its melting temp.

If given a choice, I would pick the lead-free one to use for this since the solder is the current-carrying conductor - not just bonding them.

Brian, is that to say that the leadfree stuff is a better conductor? I would imagine that in many instances the solder is the current carrying conductor. When I solder my connectors, only relatively small parts of the wire are actually touching the the connector. I just assumed that the solder also served the purpose of carrying current.

Perhaps I should go pick up some of this leadfree stuff and re-do all of my equipment.

On the other hand, car battery terminals are made of lead, aren't they? Or is that comparing apples to oranges, due to the different loads involved.

I just assumed they added the lead to make it melt easier and at a slightly lower temp than the tin. I know the tin is harder and higher melt temp. Also the lead is probably cheaper.

I was thinking that the 4% silver stuff would be better just cuz it more silver. But I didnt know if the lead actually had any other benefits.

Well, I just tried to search online to get a comprehensive list of the benefits of silver vs lead solder and this is what I was able to compile:

• Silver is a better conductor. Meaning; less resistance, which equates to less voltage loss. Not really a huge deal until you start getting into the higher currents where you start getting more voltage losses. If pulling 100A through a contact resistance of 0.001 ohm, 0.1v is lost. Ohms law, that's all.
  
  
• More environmentally friendly. You don't want to ingest it (duh). Lead is bad, nuff said. :)
  
  
• Silver has a higher melting point. This is good and bad. Good because it means it won't melt as easily if there is a ton of current - bad because it's harder to solder.
  
  
• Silver solder is generally more expensive.

From the research that I did, it also appears that the lead free stuff doesn't flow as well and calls for some sort of specialized flux.

I don't know. Some of the things that we solder, like the battery and motor leads on the MM, are hard enough to solder as it is, without going to a solder that needs a higher temp to melt it.

I could just get an 800* tip for my metcal, but then parts might start falling off of what I'm working on.

metcal?

Sorry, Metcal is now marketed under the name of OKI. I have a Metcal MX500 soldering station. It is rather unique, in that the tip that you use determines the temperature at which the station operates. Tips are available in 500, 600, 700, and 800 degree increments. The power supply for it is about 10" tall, 5" wide and 4" deep. It's a monster of a soldering station. It heats up in about 30 seconds and will hold its temperature, even on the largest of ground planes. With a 5mm 700* chisel tip, it will heat up a 5.5mm connector (that is clamped into a steel jaw vice acting as a heatsink) and the 12 wire that I am soldering into the connector in about 4 or 5 seconds, depending on the ambient temp.

I know that many might disagree, but in my opinion, it's the best soldering station that you can get for basic electronics soldering. The one that I have retailed for about $500, but I got mine on ebay for $200. Additional tips can be had for about $12 on ebay. It's a kick butt setup.

I've soldered everything from very fine electronics (0603 sized smt stuff) to making repairs on 1/2" diameter copper rod with silver solder with this thing. OK, I'll stop raving. I just love my soldering station.

LOL, I feel like such a noob since I'm still using a 40W Weller, or a 100w/250w (selectable) soldering gun for the big jobs. :)

Oh, I only got the metcal because I was, at times, soldering on pcbs that could wick up some heat. I needed something that could move lots of heat fast. It just so happens that the station serves well in the RC hobby as well.

I use a Weller soldering station, it has temp probe in it to maintain temp and heats up in about 30 sec.

Must work well for motherboards then. The ground planes on those things can really sink some heat! Makes replacing caps a PITA...

Motherboards are easy. Through hole stuff is a snap. What's really cool is the soldering tweezers. Great for soldering and desoldering smt stuff.

I removed all of the old solder from the back of the motor last night (well as much of it as I could get off) and resoldered the whole thing with the lead free silver solder. That stuff definitly melts at a higher temp and doesnt flow as much as the other stuff so I was able to build up a much taller bead of solder on the trace. I took it out tonight after work and ran a pack through it. I looks like this solved the issue. It ran great all the way through the whole pack. This time the motor and esc temps got a little higher cuz I was running in grass that was pretty tall and its a low buggy so it created quite a bit of rolling resistance. I didnt have my temp gauge with me but the motor got just hot enough that I couldnt hold my hand on it past a count of 5. But its all good. No thermals and no meltdowns of the motor.

I guess all solder is not created equally. At least I learned something from this and it only cost me a few buck for some better solder to fix it.