Soldering issues Soldering gold-plated parts can be problematic as gold is soluble in solder. Solder which contains more than 4-5% gold can become brittle. The joint surface is dull-looking. Gold reacts with both tin and lead in their liquid state, forming brittle intermetallics. When eutectic 63% tin 37% lead solder is used, no lead-gold compounds are formed, because gold preferentially reacts with tin, forming the AuSn4 compound. Particles of AuSn4 disperse in the solder matrix, forming preferential cleavage planes, significantly lowering the mechanical strength and therefore reliability of the resulting solder joints. If the gold layer does not completely dissolve into the solder, then slow intermetallic reactions can proceed in the solid state as the tin and gold atoms cross-migrate. Intermetallics have poor electrical conductivity and low strength. The ongoing intermetallic reactions also cause Kirkendall voiding, leading to mechanical failure of the joint, similar to the degradation of gold-aluminum bonds known as purple plague. A 2-3 µm layer of gold dissolves completely within one second during typical wave soldering conditions. [1] Layers of gold thinner than 0.5 µm (0.02 thou) also dissolve completely into the solder, exposing the underlying metal (usually nickel) to the solder. Impurities in the nickel layer can prevent the solder from bonding to it. Electroless nickel plating contains phosphorus. Nickel with more than 8% phosphorus is not solderable. Electrodeposited nickel may contain nickel hydroxide. An acid bath is required to remove the passivation layer before applying the gold layer; improper cleaning leads to a nickel surface difficult to solder. A stronger flux can help, as it aids dissolving the oxide deposits. Carbon is another nickel contaminant that hinders solderability.
I had the heater plug burn the white connector on me last year. I cleaned the connector and did a temp fix on it and forgot about it and it it still working fine. I used the wire insulator off of normal automotive wire and cut it in half length wise so it looked like the letter c and was about a 1/4" long, pulled the prong back and inserted the insulator behind the prong to keep tension of the prong. Has worked fine for about 10 months, LOL, that reminds me I have to get a proper repair done on it this winter.
There is no gold soldering. The gold is on the contact points to the male connector, not where the wire attaches. Kai
