Originally Posted by goboatingnow
for battery terminals, you need access to the proper high performance crimp tool. Otherwise you get teh effect that you witnessed. proper crimps should never need to be soldered.
They don't need to, but for a "perfect" 20 year + connection, with 100% continuity, they CAN benefit from it. (It is best to start out right, with finely stranded "tinned" copper wire).
On my own boat, I do both, CRIMPED & SOLDERED... then heat shrink. Then Scotchbrite the battery lug screws and cable eyes bright.
Next I wash both with iso alcohol, and let dry.
Then I apply "Jet Lube" electrically conductive grease, (with copper powder in it), to the mating surfaces, and screw the cables down TIGHT.
Now I wash again but with mineral spirits, to get ALL excess Jet Lube off of the NON mating surfaces. Followed by another alcohol wipe to get the mineral spirits off.
NOW, I have a "perfect" electrical
connection with conductive grease "in" the interface, and the outside metal is shiny clean. This is followed by 6 coats, (30 minutes apart), of "Liquid Lectric Tape", black vinyl coating. I coat the cable eye, several inches up the cable, battery post, and a 1" ring on the battery top around it.
A decade or so later, when I peel off the coating, the metal is as shiny as day one, and the connection still perfect. Only by looking at hundreds of 20 year old connections, do you see how inferior "crimped connections" are, compared to "crimped & then soldered"! Yes, it's a lot more hassle...
This is time consuming enough that I don't often do all of these steps for clients, but do "go for it" on my own boat... At least on the most important, really long term connections, like house batteries and lightning
BTW, there are a couple of often repeated myths about soldering somehow being a bad thing...
The one about "hard spots" being created at the eye are irrelevant, if you do it right, not TOO much solder, and don't let the wire flex back and forth. All boat wiring
should be kept motionless. I fasten mine every 6" for the entire length of the boat. If you flex "crimped only" fittings for decades, they will also fail at the eye!
Another myth, is that in an electrical short situation, a soldered eye can let go. This is also not true if it is a crimped first, THEN soldered connection. Even if the solder DID melt, you would be left with a standard "crimped connection". Besides... as a back up safety
, I have high A. fuses
for both the house and engine
batteries within 1' of the connection, which would melt long before the solder in the eye does.