Which flux please?

[ptrott]

What would be a good water soluble flux to use when soldering copper joints with plumbers "soft lead free solder", the one that looks like "flux core", but thicker and no flux core.

Bunnies sold me Ezy-Weld 602, which despite me physically cleaning the copper up perfectly, and roughing it with s.s. wire brush, this flux just doesn't work at all.

I watched a guy on youtube using the same type of solder with who knows what flux, and it tinned & flowed just like silver solder does on copper pipes.

Thanks in advance.
Phill.

[Master Splinter]

Ezy-Weld 602 is a silver solder flux meant for silver brazing operations.

For standard lead/tin alloy solder and copper, try - http://www.bunnings.com.au/tradeflam...rush-_p5910273

The stuff I use is not water soluble and looks like mid-brown boot polish. One of my Bunnings grumbles is that they never seem to have a decent solder/copper flux available, but heaps (Bakers Soldering Fluid) for those three or four people in Australia who still solder galvanised gutters together.

[Karl Robbers]

While not technically correct, I have used Bakers solution on copper and brass, (typically automotive radiators), with quite good results in the past.
Bunnings is usually my last choice for anything welding related as they charge like wounded bulls and their range of items as shown by your example of solder but no flux, is unusual to say the least.

[ptrott]

For standard lead/tin alloy solder and copper, try - http://www.bunnings.com.au/tradeflam...rush-_p5910273

The stuff I use is not water soluble and looks like mid-brown boot polish. One of my Bunnings grumbles is that they never seem to have a decent solder/copper flux available, but heaps (Bakers Soldering Fluid) for those three or four people in Australia who still solder galvanised gutters together.

You are spot on Master Splinter. I have used the 602 for silver soldering previously, which is why I was skeptical about it for lead free on copper. That link you posted is the Lead Free flux for the solder I bought, same brand as the solder.
Now here is the weird bit, the Bunnies I bought the solder from does not stock the flux .
I had to drive to the next town, 70 km away to get it from their Bunnies
Turns out that the solder & flux are what they call a Vendor Product.
Apparently most of the stock in Bunnies is not their own, and is replenished by the Vendor, who also decides what the shelf space is used for.
So, if a particular product does not move fast enough, it is no longer stocked. It is quite obvious to consumers of the product, that a tub of flux will last for 4 or 5 rolls of solder, but the twit that the vendor sends out would not have a clue of that, so doesn't restock it because it isn't moving as fast as the solder!!!
It was all news to me, but certainly explains why Bunnies are so regularly out of the things you want. Apparently anything with a "V" on the price label on the shelf, is a Vendor Product.

Karl, I have never had any luck using Bakers on anything to be honest, so you are a better solderer than me . I do seem to recall as a kid seeing my dad chuck bits of zinc into some acid, to KILL IT was the term he used I think. I don't know that there is anything much around these days that is Galvanised, since Zincalume took over.

That "boot polish" like substance you mentioned Master Driver sounds very much like a product that I used to use about 40 years ago when I worked on underground cables for the power company. It was called Tinmans, and I would love to get hold of that in a handyman sized amount. It was fantastic for use with PbSn tinning solder.
We also used a product called Kynal (spelling?) for soldering Aluminium which I would also love to get hold of as it would make the ali-solder flow like oil over the ali surface, too easy

Anyway, the good news is that the Lead Free flux sold at SOME bunnies, under the name of TRADEFLAME (a Companion brand) works a real treat with the Tradeflame solder. Both are expensive, but the solder is VERY expensive at over $20 for a little roll. It does go a fair way though to be fair.
For me it was worth it because I can use it with MAP gas, instead of paying big $$$ to rent Oxy Acet. bottles again. I use CO2 for my MIG now, so BOC get zero $s from me now

Thanks Gents

[KBs PensNmore]

What Karl said, plus the fact that the staff know absolutely nothing about any of the products, they think you are illiterate, they read/tell you details on the box, as if we can't read. Definitely my last place of call, sometimes I wait until Monday when a decent store opens. I've even helped their customers and staff out by getting the product or telling them where to get it. One couldn't even work out how to get a tap apart.
Kryn

[Master Splinter]

Well, it looks like yet another case of Australian retail having a chance to do the "Booo-hooo, why u not support local shops" moan.

Plenty on ebay, cheap, too....
http://www.ebay.com.au/sch/i.html?_f...+flux&_sacat=0

Oh, zinc in hydrochloric acid (till the acid stops fuming) is known as killed spirits (zinc chloride). I can remember a gutter being fixed at my primary school back in 1971 by a guy making some to help with the soldering on the gutter.

And of course, if the product is not on the shelf, it won't get sold, so there will never be any demand for it, and as you can't buy the necessary adjunct, you'll eventually loose sales of the related product as well. Good to see that innovation in Australian retailing is alive and well!

[ptrott]

...................
Plenty on ebay, cheap, too....
http://www.ebay.com.au/sch/i.html?_f...+flux&_sacat=0

Ebay has its uses, and I do use it a lot, but when it comes to needing to know for sure that what you are buying is what it says it is, ebay is not that flash. I have to be sure that the solder is actually LEAD FREE.

For example, these are both from the same ebay listing
Screen shot 2014-12-15 at 10.48.13 AM.jpgScreen shot 2014-12-15 at 10.48.37 AM.jpg

[soundman]

Firstly I'd like to know why the solder has to be lead free.

The europeans are beating the lead drum like there is no tomorrow....it has very little to do with dietry intake of lead, but more to do with lead in land fill.

But prior to all this who-har, lead/tin joints where very common on all sorts of stuff, even stuff with food contact.

I have not done any work with lead free solder...but a lot of electronics is comming soldered with lead free solder to comply with europpean requirements.....the general consus is that it is not as reliable....seems it is a problem with the joints wetting out and it is a durability issue with the solder not copeing the heat or movement as well.


back to the subject of bakers soldering flux......it IS killed spirits...aka zink chloride....with a smidge of amonium chloride for extra zing.

the problem with lead free solders is......the behaviours are still not anywhere near as well known as lead/tin solders and they continue to fiddle with arround 5 different metals to try and get it to perform anywhere near as well and lead/tin,

Lead in solder is what makes it flow out well as well as a few other things.

lead and tin in solder have an afinity with zinc.....this is why zinc chloride is used as a flux.

If you are going to have sucess with lead free solder, you will most likely need a specific flux for that formular of lead free solder.
Lead free electronic solders are flux cored so the compatibility issue does not arise out side of high volume industry.

as for not having sucess with bakers soldering flux......well that depends on what you are expecting from it.

Because it is killed spirits, it is not particularly agressive on some metals.
It works very well on gal and zinc plate.....because there is already zinc there and that reacts very redily with the zinc chloride and remnant hydrochloric.
In my experience on gal and zinc plate.....the trick is keeping the flux off areas you do not want the solder to flow on.....even then it will flow out under the oxide layer, because thet metal is already zinc tinned.

Tarnish on copper can be quite resistant and bakers simply will not touch it......so you have to either mechanically remove the tranish or go more agressive and use straight hydrochloric to clean the metal and then the bakers as a flux that helps tinning.
AND the acid does not act as fast as some would think.


First and above all when soldering copper.....cleanliness is next to godliness.......unless you have that copper bright and clean, with no oxide.....that means mechanically or acid cleaned in the last hour.....you are wasting your time...no matter what solder or flux you are using.


Now...once you have your copper clean, you may be able to use resin as used in electronics.....originally this was plant bassed.

I have not tried to buy resin flux for quite some time.....I still have a bottle that I top up with a bit of meths that I mixed up over 20 years ago......I have suspicions that it is shelac bassed

Although some of the electronic resin fluxes are water soluable.....mostly they are not but they can be redily cleaned off with alcahol.


If you must be lead free, my recommedation would be to go to silver solder.....higher heat is required, but it is a far stronger solder and its behaviour is far more predictable and well known the lead free soft solder.

OH.....BTW......I'd like to hear if any plumber in this country has ever used lead free soft solder......if they solder at all they would be using good old lead/tin or they would be silver soldering.........I would not call it "plumbers lead free solder".....I'd call it "retail suckers lead free solder".

Sorry.

cheers

[ptrott]

All good info thanks Soundman.
The end result is that I needed lead free, and didn't have access to the heat required for silver solder, so ended up with the Retail Suckers solder and the correct flux for that particular solder.
It has a melting temp of 220C which I think is a bit hotter than most electrical solders, and supposedly contains some silver.
I am assuming that those two points should mean that it is a bit stronger than lead/tin solder?
I also had to have water soluble solder as the item is to be used for alcohol, so alcohol soluble resin might have resulted in contamination, or not.
FYI and that of anyone contemplating using the same stuff It actually flowed very nicely with the right flux, very much like silver solder does, and penetrated the socket joints fully. I was a bit surprised at how easy it was to use, and it seems quite strong enough for my purpose. The flux washed out nicely with water and there appears to be no residue.
As far as aesthetics is concerned, it is far easier to clean up excess & runs than it is with silver solder, if appearance is an issue.
I would have no hesitation in using it again, but Soundman is spot on with the advice that it has to be used with flux that is made for that particular solder alloy.
No amount of cleaning and Bakers fluxing would produce results anywhere near what I eventually got when I used the correct flux.
Cheers,
Phill.