Need some help soldering Binding posts.

I need to replace my posts on my speakers.I've an excellent soldering station
and will be using cardas solder.
All binding posts have a hole what is its function?
When applying the solder I've noticed I must use more and apply over a greater area,Is this correct?
Is it ok to use flux on the post and cable then solder?
Any advice.

I'm no expert, but I have soldered Kimber hook-up to Cardas copper posts recently. The one thing is, it takes a bit of time to get the post hot enough to melt the silver solder. Put the tip on the post and the wire and leave it there. I keep touching the solder to the post and the wire cause that helps to conduct the heat to the post. Once I see that the solder will melt on the post only, I go for it. I don't know what that sideways hole is for. I wanted the wires to come straight out of the post, so I didn't use it. One other thing....Cardas and some other wire, I assume, has a coating on it that must be removed before solder will stick to it. Otherwise the big thing is getting the post hot enough. If cardas solder is like Wunder solder, the flux is in it.

I realize this is a very old post, but I felt it was my duty to let others know because I had recently searched the internet for answers and this post was as close as I found, but there were still unanswered questions.

For those of you who may not know yet, brass is a relatively poor conductor. (Btw, do not use the brass jumpers if you are not bi-wiring, instead pull off the binding post cup and solder the wires to a single pair of BPs per speaker.) Spring for solid copper BPs with Rhodium or gold plating (not fake copper ones from Ebay) and make sure your spades are plated solid copper too. Rhodium is more durable, so I went with those because I figured I would be using these the rest of my life when switching between speakers over the years, keep the original hardware. (The same reason I sprung for the Furutech FP-201 spades in rhodium for my speaker cables)

I have 10 pairs of Cardas BPs and I originally had inserted the hookup wire into the BP’s cavity and filled it up with solder using a 60 watt iron. (Took lots of solder!) Sound was improved and I thought that it was the highest possible fidelity from my system. However, as time went by and I upgraded my system time and time again, I realized that solder is bad for sound because it is a poor conductor, excepting the silver, and there really is not all that much silver in the solder.

So I clipped off the hookup wires, got a Weller professional 300 watt gun, drilled holes in two pieces of oak scrap to clamp the BP in while I hit it with the Weller. The "old" solder poured out onto the tile floor.

I spoke to Cardas and this is how they told me to do it:

Using that same high wattage gun it was time to do this the right way:

Use some flux in the front portion of the BP’s hollow "tube" where there is more of a trough.

Tin the hookup wire and lay it in the trough.

Heat the assembly, then feed Cardas solder up through the little hole at the bottom of the trough. Use just enough solder to secure the hookup wire. Hold the hookup wire perfectly still. I
used the end of a wooden cleaning swab.Do not fill the entire cavity with solder.

High watt solder gun heated the BPs so quickly that it was amazing how I could finish a solder even before the other end of the BP became all that hot.

Sound improvement was far beyond what I had expected!

Solder should never be used to glue things together. The connection should be made physically sound first.
Use PLENTY of HEAT - we use TWO 35W soldering irons when soldering binding posts - and +1 to the comment above - there should first be a very solid electrical connection then apply solder to make it stick.

Good Listening