Silver solder or 40/60 tin lead based

[jj2003]

Whats best for battery, ESC and motor connections? I have both and want to solder on some 6mm bullets onto the 6s packs I have. They came with deans but I'll be pulling about 150-170 amps at full throttle and deans wont work. So off they come and swap to 6mm. In the past I've used 40/60 tin-lead with no issue's but I've only run 6's. Now I'm running 12s on 3740's 1180kv and I'll be pulling much higher amps. Just looking for opinions based on experience, any and all welcome

[jkr]

I don't know but i use silver solder with 4% silver as it has less resistance.

[m4a1usr]

The advantage to using 60/40 is you dont need as much heat, structural strength is not required, it bonds well with most of the common metals used (copper/brass) and gives you a visual guide as to the quality of the joint you just made (shinny and even surface). Eutectic solders do require more heat, offer little improvement in lower IR and provide little to no visual guidance as to how well your solder joint was made (dull finish). More and more electric equipment we use, motors and ESC, come with lead free solders (eutectic) in the product and its extremely hard to inspect the solder joint as one of quality. Search this topic about electronics and other web sites about motor failures. You will see a surprising trend in the last 4 or 5 years. Factory motors failing in medium to moderate voltage/amperage conditions. Why? Poor solder joints on the bullets. With rapid pace motor assembly and the use of non lead solders the poor quality joints are hard to spot.

I'm not going to say 60/40 is the best solder to use but if you are solder certified, and I am, there is no mistaking a bad solder joint. With solder that does not offer visual clues as to its quality of adherance you have to rely on your experience level and knowledge of what you are connecting. Just my 2 cents.

John

[NativePaul]

I suppose you could use silver solder on motors with the winding wires coming out of the can like Neu, but if you try that with motors like Castle that are extended from the factory you will melt the solder used to join them inside the can before you get the ends you are trying to join hot enough to flow silver solder with your blowtorch, and as John said you don't need the structural strength of silver solder. I wouldn't try to silver solder an ESC or a LiPo at all, ESCs have lots of electrical components that are fairly sensitive to heat and big copper boards or bus bars that conduct heat to them well and are best soft soldered with a high wattage iron of a large thermal mass so you can solder them quickly and minimize heat soak. As for LiPos, while the rest of your equipment may die from the heat needed for silver soldering, trying that with a LiPo may not only result in a wrecked LiPo but also the serious risk of a fire.


In my opinion sliver solder has no place in any electrical wiring and soft solder should be used. My preference is for 63/37 lead tin which I find better than 60/40 because I have kind of shakey hands and find the eutectic hardening gives me a better chance of a good joint on the first attempt, but 60/40 works well too and is easier to get but as I have to order any lead based solder where I live it doesn't make much difference to me, all I can buy in shops near me is lead free which works but I do not like it, it has a higher melting point than lead based solder (though still usable with an iron unlike silver solder) and the ones I have used are a little thicker when wet meaning they didn't wick as well (your mileage might vary, I have limited experience with it as I am non-commercial so I don't need ROHS compliance and don't eat my wiring often, I only tried 2 types before going back to lead), I am interested in the lead free eutectic solder John mentioned, as both lead frees I used were far from it, having a much longer period of plasticity than 60/40 and necessitating my jigging wires to avoid dry joints caused by me moving the wire during the period of plasticity.

[siberianhusky]

I use 3% silver on all my connectors, works fine with a good quality higher wattage iron, has the bonus of lower resistance than 60/40 and is stronger, which on a bullet because of the kind of abuse they take is good.
I agree about not using it on circuit boards though!
The secret to good soldering is having an iron suitable for the job, While you may be able to heat things up enough with a little 20 watt pencil it will take forever and heat soak will become a problem, whereas my big 100 watt iron with a nice sized tip will heat up a 6mm bullet and wire in seconds without letting too much heat travel back up the wire.
Proper tool for the job is the key. A small pencil for delicate small work and a big honker for bullets, soldering threaded ends on rudder push rods, brass tubing etc.

[jkr]

Yes you don't have to over heat the component.
The solder that i use is audio grade and it needs same amount of heat.
I use somethink like this

http://www.ebay.com/itm/FURUTECH-4-Silver-Solder-20-Length-/130574344226?pt=LH_DefaultDomain_0&hash=item1e66d66022

Audio grade solder is the best but is expensive.
That solder you can use everywhere you want.

[iamandrew]

Ive bought some special silver solder, and found that it absolutely destroyed the soldering tip. It wore a hole in it after only about 30 minutes of using it, never had that problem with lead based solder..
One of my friends is an IC tech so i might just give me stuff to him to get him to solder!

[LarrysDrifter]

I use 60/40 for everything. 60 watt iron for tinning and general soldering and a propane torch for installing bullets onto the leads. Ive never had a problem with 60/40 or my method of soldering.

[NativePaul]

96/4 is a lead free soft solder with a small amount of silver in it, not silver solder. You cant use any iron for silver solder it melts at over 500c compared to 183c for 63/37 and 221-246c for 96/4.

[Alexgar]

I use either 95 tin 5 antimony and silver I've had better luck on the high amp draw setups with the silver as the tin has desoldered on my stock pb fastech and df29 using silver I've had many good runs but on the spec motor and esc setups either works the same

[jevmax]

Answer is..........60/40

[jkr]

So.
For general propose 60/40.
For better conductivity 96%sn 4%ag or 95%sn 4%ag 1%cu :)
I believe that with copper is even better!
Realy like this thread.
Before one day had no idea wich solder was better or with extreme contuctivity.
I also read that the cables have ag tin on it.
That gives speed to the electrons!

[jkr]

And i'm sorry for the misunderstading.
I ment silver solder for the 96/4 not 100% silver

[NativePaul]

No worries, silver solder isn't 100% silver either, generally between 40-55% silver the rest being copper, zinc and tin.

[Varmint]

I have to inspect solder joints at work and we do not use any eutectic alloys at all. It is all lead/tin in varying ratios to Mil-spec. It has better adhesion and less cold flow characteristics. We build airplane parts so it is all spec'd out anyway. I use a Kester 60/40 with the non-corrosive rosin core. Cannot remember the P/N but it was $15 for a pound about 2 years ago. Most if not all electrical solder is rosin core but the cheaper ones use something to clean that eats the soldering tip and turns the joint at the connector different colors depending on the base material. In other words "corrosion" after a while. Not sure what they are using for flux. I doubt the resistance of the joint is any better with a silver bearing alloy, I would think it may be worse due to the way the stuff cools and leaves a porous surface. SMT may be less sensitive to the porosity than hand soldering though.

Do not go to Radio Shack, Home Depot, Lowes, or your local hardware store for electronics grade solder. Odds are it is cheap and will be corrosive. Get it from an electronics supply house like Newark or Allied Electronics. Last 2 pounds I got were from Newark.

P.S. Don't blow on the joint to cool it, you are inducing stress into the joint because the outside cools too fast and the center is still cooling, solder joint gets dull and kind of grainy. Not good... I clamp anything I solder so the joint is not moving while it cools.