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

I had to unsolder some components from a double sided board and my wicking wire was old and lost its flux. The paste just wouldn’t melt and wick itself into the flat copper wire. The liquid worked perfectly. You might think that I could just buy wicking wire - true, but I have about 10 rolls.

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!

those who know, use it. those who don”t, should. provides an essential tack to whatever you are soldering, for the solder to jump and stick to. use after cleaning with kester brand cleaning flux, helps prevent oxidation while soldering when used correctly.

This is some of the best flux you can use for electronics soldering. The bottle is a little hard to open and it's a little pricey, but it does a fine job and makes soldering easier, and gives you quality solder joints. Other flux products I've used do not work nearly as 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.

This is a handy 2 ounce size with a dispenser. I could write pages of material in this review but I will spare you the long story. The product is works as needed and cleans up pretty easily off the joints. If you are looking for a flux to impress your neighbors and friends, this is your product!

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 purchase! shipping was insanely fast! got them a day early! Not much can be said about the actual product as Kester brand is always top notch. i got both this 186 and the 959T for my needs and that will cover pretty much everything i do. BGA, SMD and through-hole (re)work. I don't use the nozzles that are included, i use acid brushes. but i did test them and they are ok, can be a bit overkill if you don't take your time. my best advice is use a brush. The only thing i wish the seller would do is carry some bigger size refills. hint hint... LOL TLDR; This stuff is great, it does what it is supposed to do and I've never had an issue with it. The seller was AWESOME! Shipping was Great. Great experience overall!