Solder flux recommendation

[swpaskett]

(Busy people may just want to jump to the last paragraph) I noticed recently that my 13 year old bottle of flux (I date all my chemicals when I buy them, a byproduct of working in aerospace for about 10 years) wasn't working as well as it used to. I decided to draw a "fresh" 1/4 ounce of so out of the big bottle and noticed as I shook it, there was a large chunk of clear stuff inside. This flux is MG 835, a rosin based flux and it appears that after all these years the rosin separated out from the solvent and I had been using more-or-less just solvent for I don't know how long. Not complaining about MG, the flux works great when fresh and I have no legitimate expectation for it to last forever.
I am in the market for a new bottle of flux. I find the concept of no clean flux a nice idea, but in practice, again on the high rel line at Motorola (remember them?) they used no clean flux and cleaned the boards anyway. Old habits die hard and I clean off my no clean flux when I happen to use it. (I am sorry I take so long to ask a simple question.)
So, after the big buildup, in liquid fluxes, what do you use? I don't like pens, I am a dropper bottle, Q Tip old fashioned guy who doesn't want to change now. In terms of what I can buy, under the $20 per ounce price point, I have MG835 at about $4/oz, several flavors from ChipQuik about $15/oz, and Kester at $101/gal in 12 gallon lots Kester is cheap at raound $1/ounce, if I could buy it that way, but all I find is gallon bottles. Great for those running reflow or wave solder machines, I guess.

Where is that question? Oh, yeah, here it is: What is your favorite liquid flux (not pen), why, and where in the USA do you get it in home shop quantities?

 

[scott2000]

No favorite but some like the circuitworks stuff...3220..? I think there are Epay sellers that sell smaller quantities of it and maybe other flux in general....

 

[ruffrecords]

Why do you want separate flux. Don't you use multicore solder?

Cheers

IAn

 

[swpaskett]

@ruffrecords - I do use fluxcore, but there are times, such as when desoldering and working with SMT stuff that it is nice to lay on a bit of extra flux. I always dip the end of my desolder braid in it; it's amazing how much better it works. It lets me set the iron to a lower temperature, which is getting more important these days. And old habits die hard. Back in my younger days at Motorola they never sent engineers to solder school, but I watched a lot of assembly workers and, particularly when soldering the little flatpack transistors and logic gates (which are huge by SMT standards now) they always fluxed the board first. This was all flight grade hardware and we did a lot of things that probably seem unnecessary, but it is what I learned by watching the pros and it stuck.

 

[swpaskett]

@scott2000 - Dang, I never gave ebay a thought. Thanks. Lots to choose from there.

 

[swpaskett]

So I ordered a couple ounces each of Kester 951 and CircuitWorks 3220 from some ebay flux store, neither of which I have used but both will probably be satisfactory and probably outlast me. Thanks again for the pointer, I don't know why the thought eluded me, unless it is explained by age.

 

[Ricardus]

I always have good luck with anything from Chipquik. I have some of their paste flux, and it's good.

 

[swpaskett]

Yes, i have used Chipquik too, but I didn't see any liquid flux on their site.

 

[Ricardus]

Yes, i have used Chipquik too, but I didn't see any liquid flux on their site.

It's been a while since I looked on their site. But I thought they had it.

I'm pretty sure I bought a liquid flux pen from them once, too.

 

[amplexus]

Why do you want separate flux. Don't you use multicore solder?

Cheers

IAn

Personally, I use it all the time on old gear- often the wires and leads and old brass eyelets may be a little extra corroded or gunked up over years and a dab of extra flux helps them wet faster and better.

I also use it pretty much daily when tinning leads with my solder pot or dip soldering small pcb assemblies. Strip, flux, dip! Saves me hours when building cables, snakes, dsubs etc….

As to the op question, I’m still a fan of MG fluxes and cored solder, both RA and No Clean. Maybe it’s due to them being Canadian based and me being 45 minutes from their main manufacturing plant- but I never have issues finding small quantity packages of their stuff. I can usually get it all down the road at my local electronics parts shop.

 

[RBBlackstone]

I like the tacky flux that is used for SMD work. The syringe makes it easier to work with and the tackiness holds the flux in place. Kester is good and you can get no-clean if you want. Ammtech is good, too. Look for the real product. There are counterfeits out there and they are pretty nasty.

 

[swpaskett]

@RBBlackstone - Yeah, counterfeit everything these days. The ebay seller I found sells a variety of fluxes, all repackaged for the benefit of those of us who can't buy it by the barrel. He has a good reputation on ebay; that may not mean much. I will never know if what I ordered is what I get, but I will try it out on something I won't mind throwing away and see what happens. Thanks for the reminder; you can never be quite sure what you are getting off ebay.
Off topic - ebay used to be a great source for counterfeit SM57s. $13 each. In counterfeit Shure box, with warranty, paperwork, serial number, the whole shebang. Eventually Shure got control of the trade, but I bet it cost them a bundle. Dang, hijacked my own thread. No one need respond.