Kester 186 Liquid Soldering Flux, RMA Rosin, 2-ounce Bottle

This is the best flux I've ever gotten my hands on. Burns quick, less residue to clean off than other brands- when in doubt go Kester!

Great product

It's a convenient, small size for manipulating in tight spots. It also has a needle-like (blunt) dispenser nozzle that makes it easy to get just enough flux where you want it. I will buy it again when I run out.

A friend told me about liquid flux. I had been using paste. This dropper bottle and the quality of the flux is great.I work with kids soldering kits, and when they really screw up, it is often the case they have too much solder but not in the right place (up the component lead, but not connecting to the PCB pad, for example). Since there is enough solder, but the flux is long gone, a droplet of this great flux makes it do what it should: make the solder "wet" the connection and flow properly. Yay!Negatives: No easy way to leave needle top on it, yet seal it. I pressed a small eraser over it, but it wound up puncturing the eraser and plugging the tube. Tried a rubber band, but it punched through. I take this on the road, so no convenient way to keep the bottle vertical. I would recommend an alternative if there is one - a "dispenser pen" style.

In active retirement I repair and restore great old ham radio equipment and antique old radios. The old solder is often so oxidized it won't flow and stick well when parts are replaced. In addition to using new rosin solder, a bit of this flux on the joint to be re-worked makes all the old solder receptive to accepting the new solder, to adhering to braided solder (wick) remover, and to make a good, strong, well-flowed joint. It works great for me! It's supposed to be non-corrosive, but just in case, removing any excess is a great idea!

No mess

My order shipped early and worked well

Rosin pulls solder in, remains clean, does not have any pungent odor, and stores easily. The provided long term storage cap can get gummed up a bit because obviously resin is a bit sticky/tacky when left out in open air, so I just keep mine in a plastic baggie and it works great. The provided needle tip dispenses the rosin with precision, and will tend to get stuck if left in for longer than a day. It can still be unscrewed by hand easily. This is a tremendous amount of rosin, possibly a lifetime supply if you don't solder very often. I would recommend it for someone who solders daily.