Bullet Connectors - flux or not to flux?
 

As the title says, when soldering bullets, do you put some flux in the bullet?

I've been converting over to EC5's, and have had one pull out right off the bat. I fluxed all but one or two of them.

I always turned the heat up high, heated the connector, inserted the tinned wire, and added more solder through the side hole until it was full, this was on CC connectors, never had EC5's.

Flux-core 60/40 solder & 60W iron works fine for me. Unless you use solid plumbing solder I don't see a need for additional flux, but, in that case it would be necessary.

I also build and repair stained glass, and if you want your solder to flow you must flux so I do the same on all welds always seems to give a nice wet shinny joint.
My .02 worth

I never use flux on my connectors. I use 8mm, 5.5mm and 3mm connectors and all solder joints look great and perform well.

I'm kinda thinking the flux might get in the way of a good joint on these. There is no side hole on the EC5's, so when you add flux (and yes, I'm also using flux core wire) you basically end up with this molten pool of solder with a layer of flux sitting on top. You then stick the pre-tinned wire into that pool and let it sit until it solidifies. I'm thinking that maybe that layer of flux might create a "protective" layer around the wire, preventing the solder from bonding....

MUST FLUX EVERYTHING !

When doing the EC5's I tin the wire and I'll puddle up some solder in the bullet and while still molten insert the wire. if the solder cools to quickly prior to getting the wire in just put irons tip on outside of the connector till molten again. If theres some dribble on the outside it'll still slide into the plastic plug with no problem, I use a small screw driver to push them in cause they're still pretty warm. Have yet to have a failure with any of the over 40 plugs I'll soldered.

I always use a little flux, key word LITTLE. I used too much a few times and it spreads around and really gums up the contact surfaces . Now I always clean my connectors with rubbing alcohol and "Goo Gone" solvent after soldering just to be safe.

why use a soldering iron. i use a propain torch. heat up the bullet connector feed in the solder so it fills about 2/3rds of the connector and just stick the wire in there continuing to hold the flame on the connector until the wire sucks up the solder and your done :) ive found its the easiest way for me.

1) insert solder
2) insert iron
3) melt solder until it 2/3 fills the cup
4) insert pre-tinned wire
5) allow wire and cup to 'blend' together
6) withdraw iron
7) wait a few seconds for solder to solidify

Works for me- I just use lead-free sodler and my 45watt iron, no extra flux.

I only use some extra flux when having a hard time establishing a good tinning.

Also for those cutting their Castle motor leads short and exposing the coated part of the wire. Flux will take that coating right off.

Other wise since bullets, larger bullets that is, take more heat I usually add a bit of flux to the tinned wire to assist with getting things going.

I like this idea! I have a small jewelers torch that should work quite well.

With a soldering station, I can get the cup hot and filled in about 15 seconds or less. No need for a torch (although there is something manly about an open flame!!!)

As I just had to convert some stuff to these. I drilled a couple of holes in a 2x4, stuck the bullet in, heated them up, ran some solder in, and inserted the pretinned ends. Slid the plug end on and snapped it in place and done.

I just thought of a crazy idea to make soldering bullet connectors so much easier... If anything comes of it I'll start a thread later in the Project X section.

I think at least 2 of you might be able to guess what I'm thinking about. :mdr: