Tinning flux for silver-tin soft solders?

sksengupta

Is there a tinning flux available that uses a silver- tin powder for use with 4% or 6% silver containing soft solders (Stabrite, Stabrite 8 or similar clones). I have Oatey tinning flux, but I think it is made with Oatey silver based solder in mind which has selenium and other additives. I know a non-binding flux will also work. The intended use is for both heating and potable water applications with copper and brass.
Any thoughts or knowledge would be appreciated. This would be for home or small scale scientific applications, so having a custom formulation made is not an option.
Thank you all in advance.
Regards,

Sandip

PatN

Try this site.

https://rectorseal.com/plumbing/pipe-joining/flux-products/

mattmia2

The tiny amount of a different mix of solder from the tinning flux alloying in to the bulk of the fill solder isn't going to make a difference in the properties of the joint.

sksengupta

Thank you to those who responded. My general thoughts are close to that of mattmia2, but I am also aware that impurities tend to collect at interfaces and may have a disproportionate effect on local properties, for example when non silver bearing soldering solder is used to solder gold plated leads. I am mostly surprised that nobody seems to make a pure silver-tin tinning flux (rectorseal seems to make an antimony-tin tinning flux for 95/5 solder) - I am sure people would want to buy it just to be safe.

mattmia2

People that are good at soldering generally don't need tinning flux, it is more for people that are bad at controlling their heat.

Larry Weingarten

Hi, I wonder if silver and tin are not seen in the same mix because of their very different melting points? Here's a chart from an old Pipe Fitters Manual: It's good despite the "typo" between 1700F and 1900F

Yours, Larry