What's the point of Rector Seal C-flux?

[Bob Engelhardt]

This is soldering flux that has powdered solder in it. You apply it to
the joint, heat, & apply solder. Just like you do for regular flux. So
why use C-flux?

It's not pre-tinning, as that means wetting the joint surfaces before
assembly.

And if the C-flux isn't applied to the whole joint, the whole joint
isn't going to be wetted, just like regular solder.

The Rector Seal web site says "When heated, it reduces the surface
tension in the joint and allows the solder to flow easily and uniformly
into the joint." Which is what regular solder does.

What am I missing?

Thanks,
Bob

[BQ340]

Used for Lead-free solder, which does not seem to wick as easily as the
real stuff.

MikeB

[engineman]

Back in the days when I used to repair fender dents with lead I used a
product called Tinit which had powered solder in it.
With the surface tinned all I had to do was heat the lead stick until
it sofened and apply it. I did not have to melt the lead.
Engineman

> MikeB- Hide quoted text -
>
> - Show quoted text -

[KD7HB]

Hi, Bob.
We use solder paste to solder surface mount components to circuit
boards. Both leaded solder and lead free solder. The solder paste will
melt(fuse) at slightly lower temperature than solid solder. There is
no advantage for us, except when doing boards with components on both
sides. The first side is done and soldered in a oven, then turned over
and paste applied to the pads and that side's components are mounted.
Then the board goes back through the convection oven to melt the
solder paste for the new components. If the oven profile is just
right, the paste will melt, but the solid solder on the bottom will
not melt.

However, if things are not quite right, capillary action will still
hold the bottom components. If the component is too heavy and the
solder melts, we loose the component and have to add it by hand.

In your case, I don't know if there is any advantage to solder paste.
Just a lot more expensive.

Paul

[Calif Bill]

"Bob Engelhardt" <bobeng...@comcast.net> wrote in message
news:h57vq...@news1.newsguy.com...

The flux most likely helps fill in holes in the flow.

[sta...@prolynx.com]

I've used similar stuff for copper plumbing projects, with the various
lead-free solders around, it prevents dud joints. They're making all
sorts of different soldering alloys out there, many do NOT flow like
the old lead-tin stuff or even the somewhat newer tin-silver stuff.
Heat some of it too long and it just turns into metallic dough and
doesn't stick anything together, or flow into the joint, either.

The stuff I used could be applied, heated and no extra solder was
needed on properly fitted joints. Worked well for tinning soldering
irons, too. The key thing for pipe joints was to apply the stuff, fit
the parts together and give the tubing about a 1/4 turn before
heating.

Stan

[coblin...@gmail.com]

C Flux does pretin the copper solder joint as it is applied (like regurlar flux) to the joint before soldering hence it acts inside the joint. I have used both regular solder and C Flux. Will only use C Flux now. Basically it gives a more assured solder joint than regular flux.