Over the years, we’ve accumulated quite a list of frequently asked questions (FAQs) and their answers. They range from basic, beginners questions to high-tech problems with multi-part solutions.

We’ll be adding questions and answers as we get them put into the proper format. If you have a question that isn’t answered here, feel free to drop us a line and ask.


What  is “flux”? What does it do?
A flux can either remove existing oxides from the metal part that you are trying to solder, or simply coat the part to keep new oxides from forming while you are heating it. We offer flux options for every application.

What’s the difference between “Rosin Core” and “Acid Core” solder?
Rosin core solder contains rosin, which is usually a purified pine tree sap, as a fluxing agent. The flux can be inactive, in which case it simply covers the area being soldered during the process (to keep oxides from forming), active or mildly active , in which case it will remove light-to-medium oxides that were present before the soldering process began, or highly active, which will remove almost any oxide or stain on the part and allow a good solder joint to be made. Rosin Core solders are active only during the soldering process. Activity is halted or greatly reduced after the heating process is finished. Rosin fluxes are non-conductive, and for this reason, they are the choice for electrical and electronics connections.

Acid core solder contains a water based flux that is usually highly active both during and after the soldering process. The higher incidence of oxidation (also known as rust or tarnish) usually associated with plumbing fittings and fixtures requires an aggressive, highly active flux to allow a good solder joint to be made.

While acid based fluxes are highly active, they are also hygroscopic. This means that any flux remaining after the soldering operation will acquire moisture from the atmosphere. Left intact, excess acid flux can cause moisture to accumulate to the extent that it will actually flow and puddle.  Since acid fluxes usually remain active after the soldering process, removing the residue is indicated to keep the residue from continuing to eat away at the part.

Acid based fluxes are usually water soluble, which allows for easy removal with little more than warm water and a mild detergent.

Can I use “electronics” solder on a small plumbing job?
While lead bearing solders were used for years on plumbing fixtures, it is now illegal in many states to use tin/lead solders on potable water systems. Lead will readily leech from the alloy into water, and can cause a myriad of health problems. Infants are most at risk from lead. It can cause developmental problems and brain damage.

Lead bearing solders were used because of their relatively low melting points and the ease with which they flow and bond to other metals such as copper. Alternatives such as SN95/Sb5 are used, but their higher melting points and inferior wetting ability make them a less-than-optimum choice.

That’s why we’ve developed TB1™… The Best One.

TB1™ melts, flows, and wets like a tin/lead solder, but is lead-free. And it does it at a lower cost than lead-free solders from other manufacturers.

What are all the numbers and letters in a solder alloy’s name?
Most solders are described as percentages of particular metals. Sn60/Pb40, for instance, is an alloy of 60 percent Tin (Sn) and 40 percent Lead (Pb). There are instances when a solder alloy is known by only part of that designation. Sn96, for instance is the designation for an alloy of 96 percent Tin (Sn) and 4 percent Silver (Ag).


Does solder go bad? Our process isn’t working like it used to. Why?
If it’s been more than 30 days since you changed the solder in your melting pot, the answer is probably ‘contamination’. Over time, contamination from whatever it is that you’re soldering builds up. Running copper parts through a wave soldering machine will result in copper contamination, steel parts result in iron and nickel contamination. Depending on what the contaminant is and how much of it has gotten into the solder, it may be time to change the contents of the pot.

The Torrey S. Crane Company offers solder pot analysis that will tell you if your material is contaminated and, if so, with what.

What do I need to know when ordering solder?
Most of the time, knowing the alloy, dimensions (diameter for wire or weight per piece for bars and ingots), core type (for wire) and quantity is enough. Any specifications (ASTM, QQ-S, J-STD, etc.) should also be mentioned when you place a quote request or order.

What exactly is a ‘eutectic’ alloy? What makes it special?
A eutectic alloy is one which melts and solidifies at the same temperature. In many applications, a pasty stage is not desirable, and an alloy that does not have a pasty stage is of benefit. Chemically, eutectic alloys are special because they are ‘balanced’. Their melting/solidification temperature is a side effect of this fact.


Where can I get the finest quality solder products at the best possible pricing?

Answer: Torrey S. Crane Company of course … (860) 628-4778 

How can I get more information about Torrey Crane Company or its various products?  

Answer: Click on the Info Request button, complete the form, and submit it.  We’ll get back to you with the information as soon as possible, usually within 24 hours.  Of course you can always call (860-628-4778) or fax (860-628-7817) us to get information or ask questions.  Information Request