Quick question on silver brazing flux

I've got a small tub of the Cycle Design silver brazing flux. Since the spring, it's developed a granular (okay, more like tapioca-like) consistency. The main carrier is still very wet, it's just got a bunch of very hard little balls of... I don't know what it is -- in it.

Background -- my "shop" is about 1/3 of a tar-roofed double car garage, and in the summer afternoons with the sun beating down on that tar, it gets well over 100 degrees in there. I can't even think of working out there in the afternoons. Could this be causing whatever it is to precipitate out?

Is this stuff now useless? Can it be saved somehow?

I would call or email cycle design and ask them the question.

I live in Florida, its hot. Flux dries. add water and mix it all up. Braze on.

We strive to make our fluxes as forgiving as possible, temperature extremes can effect most brazing flux.
While it is likely that the flux is still fine, it is simply not worth the risk. We would be happy to replace the flux at no charge.

Please email us to work out the details.

Thank you,
Wade Barocsi
Cycle Design
[email protected]

Hey Wade -- I appreciate the offer. I have no problem purchasing more, just was curious what might be going on with it and if it was a matter of where it's stored. I'll go off-line from here and we'll get things ironed out. Thanks!

Add hot water and stir atmo.

Just tried that. A fair amount of hot tap water, and a lot of grinding on the side of the container with a soup spoon (like a mortar and pestle), and I now have flux with smaller granules. It's like rock salt mixed into the flux... Emailing Wade shortly.

I had this same thing happen a few months ago. I didn't want to add more liquid because there was already some liquid present and differential solubility tells me that the content of the solid and liquid portions will be either side of the intended concentration.

I decanted the liquid to another jar, sieved the flux through a large tea strainer, put the fines back in the tub and transferred the coarse lumps to a mortar and pestle. I then ground the coarse chunks adding the supernatant as required to keep the right consistency (paste like).

Stuck everything back in the tub and mixed well, works like it says on the bottle.

https://farm6.staticflickr.com/5567/...6b6c8c381f.jpg

Flux bottle

It doesn't say anything on the bottle any more since I put the tub in an airtight kitchen container with a few ml of water in the bottom. This prevents the problem from reccurring but it has eaten the label.

If adding water, hot or cold, is bad for dry or dried-up silver or brass flux, then I have been a bad, bad effbuilder for 42 years atmo.

There are a lot of subtleties in the framebuilding process. Flux isn't one of them. You've received some free advice from one the greats. Add water & stir. Run with it.

This is one of those over thinking threads. Once the torch hits the flux for the requisite seconds, its as glassy as a Krispy Kreme doughnut regardless of what it looked like in the container. The water content just helps you keep flux where you want it before the torch is lit. That's my story and I'm sticking to it.

now you have me second-guessing myself, oh wait, no you didn't

I just add plain old tap water and mix it up and use the flux. Here is a crazy suggestion -- take some scrap tube and try it. What you will find is that the silver will wet out fine.

isn't it mostly borax? its just soap people. given enough time and exposure soap doesn't turn into anything but dry soap.

I don't think silver flux is mostly borax, not sure the better brass fluxes are mostly borax either.

If you have some of the powdered borax flux, heat some water up to boiling and put the powdered flux in it and it turns to a nice paste.

I add reagent grade H2O.