Soldering flux recommendations

[cameo]

I haven't bought any soldering supplies lately and am not familiar with
the latest best products. Can anybody recommend some good lead-free flux
that's easy to work with and is widely available in the US?

 

[Spehro Pefhany]

I haven't bought any soldering supplies lately and am not familiar with
the latest best products. Can anybody recommend some good lead-free flux
that's easy to work with and is widely available in the US?

I think pretty much all flux is lead-free.

But, try this (some of the items are flux remover):-

http://www.digikey.com/product-sear...ucts/flux-flux-remover/1311241?k=flux&stock=1



Best regards,
Spehro Pefhany

 

[[email protected]]

I think pretty much all flux is lead-free.

But, try this (some of the items are flux remover):-

http://www.digikey.com/product-sear...ucts/flux-flux-remover/1311241?k=flux&stock=1

The flux is lead free but flux for lead-free processes is different
than flux for leaded processes.

BTW, "lead free" and "easy to work with" don't ever belong in the same
sentence.

 

[Syd Rumpo]

I haven't bought any soldering supplies lately and am not familiar with
the latest best products. Can anybody recommend some good lead-free flux
that's easy to work with and is widely available in the US?

I use ordinary plumbing flux for lead-free plumbing[1] applied with a
toothpick or small brush. It works very well for prototyping, a small
tub will last for years, but I guess it wouldn't be approved for
manufacture.

[1] You can't have lead-free 'plumbing'. Plumbers should now be called
'tinkers' and what they do, 'tinkering'.

Cheers

 

[Syd Rumpo]

I haven't bought any soldering supplies lately and am not familiar with
the latest best products. Can anybody recommend some good lead-free flux
that's easy to work with and is widely available in the US?

I use ordinary plumbing flux for lead-free plumbing[1] applied with a
toothpick or small brush. It works very well for prototyping, a small
tub will last for years, but I guess it wouldn't be approved for
manufacture.

The ordinary 'plumbing' flux here is called S39,
it is extremely agressive and should not be used on electronic components.
http://s39flux.com/
I repeat ****NOT**** for electronic components.

[1] You can't have lead-free 'plumbing'. Plumbers should now be called
'tinkers' and what they do, 'tinkering'.

Yea, that is what everybody does, even designing trains and plane.

This is what I use, and I've been doing so for years...

http://www.gwneale.co.uk/copalux.html

....yes it's aggressive and, like I said, not for production. For
prototype building and rework it's really very good indeed.

Cheers

 

[Syd Rumpo]

On a sunny day (Fri, 22 Feb 2013 11:30:29 +0000) it happened Syd Rumpo

On 21/02/2013 01:13, cameo wrote:
I haven't bought any soldering supplies lately and am not familiar with
the latest best products. Can anybody recommend some good lead-free flux
that's easy to work with and is widely available in the US?

I use ordinary plumbing flux for lead-free plumbing[1] applied with a
toothpick or small brush. It works very well for prototyping, a small
tub will last for years, but I guess it wouldn't be approved for
manufacture.

The ordinary 'plumbing' flux here is called S39,
it is extremely agressive and should not be used on electronic components.
http://s39flux.com/
I repeat ****NOT**** for electronic components.


[1] You can't have lead-free 'plumbing'. Plumbers should now be called
'tinkers' and what they do, 'tinkering'.

Yea, that is what everybody does, even designing trains and plane.

This is what I use, and I've been doing so for years...

http://www.gwneale.co.uk/copalux.html

In case of the S39 it was the long time effect, I remember from long ago,
I soldered some Phlips 'tar' capacitors with it in a radio as repair
for someone.
The radio started making cracking sounds after a short while....
I expect the effect on SMDs to be even stronger.
Not sure what it does to very expensive plated soldering tips either.
Why take chances, special flux is readily available for al sorts of things
I even have a flux-pen (looks like a marker) for soldering strips on solar cells....

The stuff I use doesn't affect the soldering bits at all, as far as I
can see. I use it because it's so good, and better than the pen stuff
I've tried. The manufacturer describes it as a 'medium active' flux.
It's a colourless translucent paste.

A quick wipe of this over SMD legs and solder wick becomes almost
magical in its suckiness and the solder flows like mercury.

But again, not for production.

Cheers

 

[SoothSayer]

On 21/02/2013 01:13, cameo wrote:
I haven't bought any soldering supplies lately and am not familiar with
the latest best products. Can anybody recommend some good lead-free flux
that's easy to work with and is widely available in the US?

I use ordinary plumbing flux for lead-free plumbing[1] applied with a
toothpick or small brush. It works very well for prototyping, a small
tub will last for years, but I guess it wouldn't be approved for
manufacture.

The ordinary 'plumbing' flux here is called S39,
it is extremely agressive and should not be used on electronic components.
http://s39flux.com/
I repeat ****NOT**** for electronic components.

[1] You can't have lead-free 'plumbing'. Plumbers should now be called
'tinkers' and what they do, 'tinkering'.

Yea, that is what everybody does, even designing trains and plane.

This is what I use, and I've been doing so for years...

http://www.gwneale.co.uk/copalux.html

...yes it's aggressive and, like I said, not for production. For
prototype building and rework it's really very good indeed.

Cheers

If you guys are having a problem with "prototype building and rework"
having a need for an aggressive flux, then you have serious component age
issues.

Snip back the first inch of any cable you have which you intend to use
to fabricate an interlink with. If it is old cable.

Modern soldering is easy, and I have never seen the need to use any
such aggressive flux to wet a connection.

Either the wire is too old, or your understanding (lack of) of thermal
masses is lacking, or both.

I have found that silver plated mil wires and cables are far easier to
work with than tin plated stuff.

Tin plated HV cable acts like it was coated with ultra-ever-dry. Very
hard to wet, but still doable. I always spec the SPC stuff.

 

[Tim Williams]

I have found that silver plated mil wires and cables are far easier to
work with than tin plated stuff.

I have some *nickel* plated mil spec telfon (mineral loaded, high temp)
wire. It takes for damned ever to tin the stuff. It's also about 10AWG.

Tim

 

[Tim Williams]

Plumbers flux is grease-based. Before I knew any better, in the early
1960s, I built a Heathkit VTVM using plumbers solder and flux. The
VTVM worked just fine, and actually still does - I fired it up just to
see a while ago.

Funny, I just did a little maintenance on my V-7A. Replaced the PS diode
(encapsulated Se), filter cap (no sign of trouble with either, just wanted
to change them), and AC coupling cap (molded axial, the kind that
sometimes goes bad), and calibrated it so it's within a few percent again
on most ranges. Still needs some Deoxit on the switches, and fresh oil in
the movement, but it's reasonable otherwise.

One advantage of this unit over most DMMs is the AC bandwidth -- it's flat
out to about a MHz, probably further with transmission line (I've got
stray banana jack cables going to it and see some zeroes in the MHz band).
Most DMMs I've seen roll off at a few kHz, not even enough for audio
applications! The manual warns that, although it may work out to 7MHz or
so, the loading will be significant up there.

Tim

 

[[email protected]]

Funny, I just did a little maintenance on my V-7A.  Replaced AC coupling cap (molded axial, the kind that
sometimes goes bad),

One advantage of this unit over most DMMs is the AC bandwidth -- it's flat
out to about a MHz,
Tim

You might increase the size of the AC coupling cap. As built the AC
bandwidth is not flat down to 60 hz.


Dan

 

[Spehro Pefhany]

I have some *nickel* plated mil spec telfon (mineral loaded, high temp)
wire. It takes for damned ever to tin the stuff. It's also about 10AWG.

Tim

You're not supposed to tin it. You're supposed to crimp it with a
really expensive tool.


Best regards,
Spehro Pefhany

 

[Tim Williams]

You might increase the size of the AC coupling cap. As built the AC
bandwidth is not flat down to 60 hz.

I'd noticed that. I calibrated AC at 600Hz. It drops off noticably by
only 100Hz, so the 120V line is only "100V". Don't think I have any 0.1
1600V handy though (it uses a 0.01).

Tim

 

[[email protected]]

I'd noticed that.  I calibrated AC at 600Hz.  It drops off noticably by
only 100Hz, so the 120V line is only "100V".  Don't think I have any 0.1
1600V handy though (it uses a 0.01).

Tim

If you paralleled the 0.01 with another that size , it would help a
lot. Should move that drop at 100 hz to 50 hz.

I have a few 1 ufd 2100 volt caps in my junk box from junked
microwave ovens, but I do not think one would fit inside the case.


Dan

 

[whit3rd]

I have some *nickel* plated mil spec telfon (mineral loaded, high temp)
wire. It takes for damned ever to tin the stuff. It's also about 10AWG.

Nickel alloys (also found in thermocouple wire and battery terminals)
soft-solder well, but the flux should be the acid type; anything recommended
for stainless steel will work fine.

The common type includes some sulfuric and hydrochloric acid; keep
it well away from anything that can rust (there's some fumes emitted).
It doesn't take much flux, just a drop on a toothpick. The toothpick
will blacken and turn to goo after a minute, though.