What is the best way to clean Flux

I use 99 percent  ipa in a spray bottle with a toothbrush there is also a great deflux spray. I get my ipa from a hobby shop by the gallon

When I was an ET in the Navy we always had multitudes of brushes and containers for soldering/removing flux.

Brushes

https://www.amazon.com/gp/product/B003X5KHHK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Alcohol dispenser

https://www.amazon.com/gp/product/B07N1G5WD5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

My method when doing SMD boards is the following: 1: before using the RA flux (since I find it a little too thick and it seems to clog the dispenser needle quite often) I combine it with 10-15% alcohol and then I pour it in the little dispenser bottle that I have (similar with the one that MCL use) that has a long blunt needle with a little rubber cap on top to seal off the needle end after use. This way, because the RA flux becomes more fluid, I find that it needs less since it spreads better and quicker and in turn could “potentially” be easier to clean later (I suppose)  2. Once finished soldering on a board I use a suitable size plastic tray with 99% alcohol and deepen the whole PCB in it. Let it soak for a few minutes and then, use a hard toothbrush to vigorously brush off stubborn RA flux areas until it looks clean. All this time the board remains submerged in Alcohol liquid. Then I take it out, let it dry (naturally), and examine it once again,  I repeat the process as necessary making sure I always use clean alcohol from the bottle! If I need to say: change a component later I use earbuds with alcohol to clean any local area. And by the way, I also have and use an alcohol dispenser bottle like the one suggested by “gbfreeman123″.  One important aspect needs to be pointed out here. Certain components cannot be submerged in alcohol since the type of plastic that they use might get attacked by the alcohol therefore they need to be soldered last minute (after the above-described cleaning. One just has to try and experiment with it As a general Idea I find that resistors, ceramic and tantalum caps, transistors, ICs, and diodes are usually ok. But… I’m not so sure about VR’s and certain inductors. So I tend to leave them out until after ” the alcohol bath” procedure and then use the ear buds to clean the soldering joints after that. Also, if the board requires the use of larger size components such as large electrolytic, transformers, etc. I also leave them out.  My take…

When IPA fail I use IPA mixed with some acetone in it. So two bottles one with IPA only and one with IPA and acetone.

Posted by: @wilhelm

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When IPA fail I use IPA mixed with some acetone in it. So two bottles one with IPA only and one with IPA and acetone.

 

I remember Mr. C say in the capacitor tester one has to get all the flux off the board.

@ovi4 Good Idea!

When I clean the board with 99% alcohol, when look under the scope, there is some flux.

I just remember Mr. C said in his capacitor tester one has to remove all the flux.

I you miss to put the cap on just add som more acetone later. I use bottles with syringe, Plato FD-2.

https://www.techni-tool.com/category/Bottles-And-Dispensers/Bottles/657CH020-FD-2

@wilhelm I use something like that for the flux, and Vivaplex, Amber, 2 oz Glass Bottles, with Black Fine Mist Sprayers from Amazon for my alcohol, but not sure if acetone would stay in the bottle.
Since I have 6 bottles, I guess I will try it.

It will stay in if you put the cap on.

@wilhelm Thank you Wil

Carb cleaner and a small nylon brush works best

@larry_n7luf i use a flix that has a uv trace in it so I can check to see that it was removed

I use STIRRI

V3-TF universal no-clean rosin-based tacky paste flux (ROL0) it has the uv trace in it