I recently got back into the hobby, and now that I am soldering again, I have noticed that the solder isn't as fluid as I remember. For example, the solder doesn't appear to liquefy and flow through the wire and motor tab. It just clumps up and seems thick which makes a poor, weak connection.

I'm wondering: Is it because I have too low of a voltage for my iron (25amps). Or am I using the wrong solder (I bought some electrical solder from Home Depot?

Thanks for any help.

That's to low of an iron. You need around a 60 watt iron for motor/battery wires. The Hakko station that goes for around $80 is the most popular.

OK, That's what I figured. Thanks.

Make sure you're NOT using leadfree solder, it has a higher melting point and it's more brittle than lead solder. I like 63/37 solder. If you really want the solder to flow into the strands of wire, get some flux on the wire before you try soldering it, apply heat and solder as usual and the solder will seem to get sucked into the wire strands.

45w works fine for all I do. 25w is fine for circuit board work but not for larger wire. 60/40 solder too. Flux on new wire/joints is a must too!

xx use flux core solder, have extra flux on hand for when you need some flow but not more solder globbed on.

Solder at home depot? Make sureits not plumbing solder. Last time I checked the store by me didn't sell electronics grade solder.

Yes you will need a higher watt iron. I would recommend a Hakko FX-888D. It's a digital temperature controlled station. Temperature control is key to make sure the tip gets hot enough but not to hot. It also has preset modes so you can program temps into it which is nice for jobs that you do frequently. I found one online by a company called production automation for under $100 which is very affordable.

Other things I would also make sure you are using flux or a rosin core solder, and to clean and tin your solder tips. That should fix the cold solder joint issues you have been having. Hope that helps!

Absolute bullocks. I have a 20 year old 35 watt stick and can assemble battery packs just as easily as servo wires. The only reason for more power is lack of skill and impatience.

Dont they sell that at Home Depot too?

You really want a hotter iron. 25 watts should do it fine with the right tip, but you will have to hold the iron to the wire for quite a bit longer, which lets more solder deep into the wire, making the wire less flexible and hard around the joint, not just the point soldered.

This is all you will ever need for the easiest flowing + best soldering of R/C (in my opinion) - I set mine to around 650 and it flows super easy:

Kester 44 Rosin Core Solder 63/37 .031 1 lb. Spool
http://www.amazon.com/gp/product/B00068IJX6
hands down the best solder available....

Digital FX888D & CHP170 bundle, includes FREE CHP170 cutter
http://www.amazon.com/gp/product/B00AWUFVY8

around 115$ total.

I have used all kinds of other ones and this has been the best!

Oh make sure to get the tip too:

Hakko T18D32P Tip for Fx-888 Station, 3.2mm
http://www.amazon.com/gp/product/B000B5YCUI
8$
you will need it for R/C, wider tip means easy heat transfer! Should be able to solder in 5-6 seconds or less, or your doing something wrong.

This is also useful :

http://www.amazon.com/gp/product/B000RB38X8
Helping hands for 6$

I just bought that list about a month ago and it has been awesome! soldered rx8 easy, motors, battery terminals ect sofar. It also heats up in about 15 seconds to any temp and keeps that temp.

Just figured id help out since I have struggled with soldering for years until I found this setup (spend a little extra money for the better stuff it's worth it and not even that expensive)