Flux...

I was doing some model aircraft maintenance this weekend, specifically changing the battery connectors. A fully charged battery passes 5 amps to the motor in 5 minutes. it's enough current to make the entire system hot. The motor gets burning hot and the wires in the system get really warm. If there is corrosion on the battery connector, the chance of it failing are great. Keeping that in mind, I changed out the connectors for a model I haven't flown in a few months.
Normally, I pay a friend to 'wrench' on my helicopters. He's got 20 years experience with helicopters and drones, doing repairs for the other pilots. This time, I decided to do the work myself.
The tools I had in my Miami house were all boxed when I sold the place and are now stored on the back patio of my condo. I had to dig around to find the soldering iron, solder and flux.

I purchased a bag of connectors from a friend who changed systems and no longer needs that style. Before starting, I watched 2 YouTube videos about wiring up this style connector and both videos had the same sequence. I did a test with some of the same thickness wire to see if I remembered how to solder. It's been a few years... I should remember this, right?

The first test failed because the heat from the soldering pencil was marginal and I had to hold it to the connector for a long time to get the solder to melt. I had it in a clip like the video, but the metal clip acts like a heat sink pulling the heat away from the connector.
I decided to take a piece of wood and drill a small hole in it the size of the connector.
Pressing the connector into the hole was perfect as the solder was now melting when it didn't before.

Electrical solder is extruded mix of tin and lead with the center core having rosin to help it stick to the the metal you are joining. It difficult cases, there is a chemical flux paste that improves the flow of the solder. I used a small amount of flux when adding solder to the wire (tinning) and some in the depression of the connector.

Making several tries, I got the 3rd set to my liking and snapped the connectors to the cap.
I owe the success of this product to the flux. Yeah, I know when foreigners say another word quickly it sounds like flux.




The only down-side to the project is /are fumes from the solder & flux being toxic.
I had a fan blowing the smoke away but the next morning I got up with a bad case of asthma.