2 oz. Non-Spill Rosin Soldering Paste Flux

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

This is the best flux I've found for electronics/telecomm soldering. It beats petroleum-based fluxes hands down.

I've been using it to de-solder and clean wiring pins on legacy telecomm equipment where some of the solder joints are more than 20 years old. Just a tiny dab applied to the joint and the solder shines up and flows like water when heated.

It leaves very little residue when used sparingly.
That's the key - a little of this flux goes a long way.

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

Earlier, I provided a first positive review of this product. This is a follow-up review that provides further useful information about soldering and cleaning, based upon several decades of personal successful experience.

If you have ever closely examined (under magnification) a modern circuit board from a reputable computer-device manufacturer, you have seen how superbly clean the board is everywhere --- top and bottom. Such boards are magnificent.

Over the last several decades while I have worked inside electronic equipment, I have observed that many (but not all) manufacturers of consumer electronic equipment have gradually chosen to spend additional effort to thoroughly clean their circuit boards after soldering them --- to prevent eventual intermittent and permanent failures due to current-leakage paths that develop over time within flux and other contaminants that remain on the circuit boards.

Some equipment failures might be due solely to incomplete cleaning after manufacturing and repairing. The circuit designs and the components of a product might be good, but the overall product might fail intermittently or completely due to residual manufacturing or post-manufacturing contamination.

Soldering-flux and other contaminants must be removed. That is mandatory. If flux is allowed to remain, high-impedance circuits will eventually become intermittent or de-tuned, or they will fail completely.

Sometimes it is possible to repair inoperable or intermittent electronic equipment by thoroughly cleaning the circuit boards and all other soldered joints. Sometimes the manufacturer failed to clean some joints that were soldered during the last steps of equipment assembly, even though most of the circuit-board surfaces were cleaned well. Those last-soldered, dirty joints might eventually cause the equipment to become inoperable.

Below is a description of what I do with all joints that I have soldered or that someone else has previously soldered, whether those joints are on a circuit board or on a simple connector terminal that is separated from a circuit board. I clean all joints, with no exceptions.

A material that is presumed to be an insulator cannot do its job properly if it has conductive contamination on it. A circuit design presumes that an insulator is acting as an insulator.

The low-impedance portions of a circuit might continue to function correctly if they are dirty with conductive contaminants, but the high-impedance portions of a circuit will not continue to operate correctly. I clean everything equally well, and then I don't need to understand or think about the individual impedances.

Using goggles (for eye protection) and a blowing fan (to remove vapors), I sparingly use denatured alcohol (from the paint department of a hardware store) and a soft-bristle toothbrush to scrub the entire circuit board, even if I personally soldered on the board at only one spot. I repeatedly saturate the toothbrush with denatured alcohol; and I scrub the entire board several times with the toothbrush and let the dirty denatured-alcohol solution run down onto a ceramic dinner plate that has a paper towel on top of it to soak up the dirty fluid.

Cotton swabs that are saturated with denatured alcohol can be used to scrub small areas that cannot be reached using a tooth brush.

After I have thoroughly scrubbed the circuit board, and after the liquid that runs off the board has become clear, I pat the board with a clean paper towel and let the board dry. Then I brush the board with a dry, soft-bristle toothbrush to remove any white powder that might remain in some areas after the alcohol has dried. The joints that I soldered are now shiny-bright, and they cannot be distinguished from the best of factory-soldered joints. All joints on the board are shiny-bright.

If there are places on the circuit board where alcohol might be trapped underneath and inside circuit-board components due to capillary action, I very carefully use a vacuum-cleaner's hose-nozzle to pull all trapped liquid from inside and underneath all components on both sides of the circuit board until everything is dry. I am careful with the hose nozzle, because it could bend or break some board components if it gets away from me and pulls itself down onto the board due to the strong vacuum. If there are surface-mounted devices on the board, I also scrub and thoroughly dry and vacuum that surface of the board.

After I have completed this scrubbing and drying process, it is finally possible to objectively examine the entire board and all other chassis connections under bright lamp-light, from many different viewing angles, using magnifying lenses. If there is any joint that looks suspiciously-bad, I re-flux and re-solder that joint and then thoroughly scrub the board again at that location.

A board cannot be objective examined for defects until it is completely clean.

I wait until the board is dry before I apply power to it. There must be no liquid trapped anywhere. I very carefully use a vacuum cleaner's hose-nozzle to ensure that all trapped liquid has been removed from inside and underneath all components.

A well-designed piece of electronic equipment can be kept working like new for many years, and sometimes for decades.

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

I stongly agree with the other reviews! Great product. Worth every penny.

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

This flux seems to work very well. I have used water based plumbing flux in a pinch before, but there really is no comparison. This stuff is sticky enough to stay where you put it, and can help to hold SMD devices in place until the solder melts. Hint: use a cotton swab to apply, works great!

This even seems to work well under larger BGA chips, but this also brings me to the only con I can think of, which is the Radio Shack near me doesn't stock anything to clean the residue off when your done. The description says to use "cleaning solvent", which is not very helpful if you don't have any previous experience with rosin based flux, especially removing it from underneath components that an old toothbrush can't reach.

If I can find a good solvent that is reasonably priced that will clean under BGA chips, I will post it here later. (Mineral Spirits, then alcohol after words works well on surface residue that you can see.)

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

I have been soldering and re-soldering and de-soldering electronic joints for more than 30 years. I add rosin flux when de-soldering joints in order to remove the old solder as quickly as possible to avoid overheating the region and to leave the area clean. Historically, I have used liquid rosin flux for this purpose, but I do not currently have any available to me. This product works very well as a substitute for liquid rosin flux. If you always add rosin flux, solder will melt and flow rapidly and will be mirror-smooth when cool. Your joints will be professional; and if you pay attention, you won't overheat the region. I often must add rosin flux to augment flux in the solder core. This is a great solution.

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

Flux of some kind is necessary to keep the lead & tin alloy in a chemical solution, and to chemically bond with other dissimilar metals during soldering operations, like copper, silver, or nickel wire. Rosin solder will not corrode electronic circuit components like acid flux will. This product is *great* for me for large surface soldering of copper flashing and tubing for building antennas and static ground systems. Note: a lightning strike will melt solder; use bolts or CadWeld. I'm making static grounds only. If you're doing non-electrical soldering, save yourself the headache and use acid flux; but for the intended purpose, this product is perfect! Thanks, Radio Shack!

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

It does the job exceptionally well.

As a NASA/MILSPEC/AF soldering pro this is currently the best product available retail. Though wishing they had a liquid version available with needle dropper. I heat mine before using a dropper to have it in a liquid state for better flow control.

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

This stuff work great. I got it for desoldering/removing some capacitors from a computer logic board and the flux made a big difference in the transfer of heat to the via holes.

It is more than I expected for the price.

easy clean up.

I would recommend this product.

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

Works great for the products intended aplication. I did have trouble finding this product in local RS-stores a few years back. It seems that the product had to carry some sort of safety warning mandated by a law in California. I feel much better that a state I don't even live near is taking the time to inconvenience me.

Comments about RadioShack 2 oz. Non-Spill Rosin Soldering Paste Flux:

Ron:

This product is specifically described as solder flux for *electronics*. It's not really fair to give this product a bad rating when you did not use it for its intended purpose.

That said, it's probably still not such a bad thing to give people a heads-up that this isn't a good choice if you are looking for flux to solder brass railing pieces together. Just in case somebody else has such an idea. :)

A brazing compound or specialty flux for your application would be a better idea.