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

Kister 186 Liquid Soldering Flux worked will in my last project. It would be nice if it came with an applicator. I used a cotton swap to apply it to the work.

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!

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!

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.

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.

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.

I’ve been using Kester products for many years, and while they are a little bit more expensive they have never let me down. I do a lot of cabling repair on micro gauge wire, and this viscosity combined with their genius little applicator tip makes my life so much easier. Also perfect for reflow work! I highly recommend and always will.

Very good flux