Flux cleaning study

[mnaty]

Found this article documenting flux cleaning processes and efficiency of removal methods. Wanted to share as the info provides some great insight into what works and conditions that can affect how you shpuld clean. See link.

Additionally, it directly states variables that back the the recommended cleaning solution by Louis. Branson cleaning agent is a nonionic surfactant concentrate with an high alkaline ph of 12.5. One other noteworthy find is that the specs for the Branson cleaning solution very nearly match Dow Chemicals ECOSURF SA-9. HOWEVER... there may be a few more chemicals involved for balancing, but understanding/discovering this potential link is what lead me to find the document in the link so if felt prudent to share.

 

[larossmann]

The way I usually do it is as follows. When I am done with a board repair, I have the JBC around 300c, air very high, and I go over the are from far away that I had flux on. I get the flux to a point where it is very hot and more thin-liquid like, rather than a chunk of caked lard shit. Right as it is hot, I dump it in the UC with the 1 gallon of distilled water/100 mg of branson EC at 60c, and turn on the sonic. 30 seconds later I turn it off, and gently toothbrush the area with the flux - while it is still in the liquid. I turn the UC back on for 30 seconds, and then take it out, dump it in a container of 99% alcohol for a minute. Then I sit it in some cheap HEPA air filter I have for a few minutes to get rid of the alcohol chunks, and then it goes into an oven for half an hour at 250f. The toothbrush gets rid of the flux the UC can't, and the heating makes it come off easier. By the end of this process you see no flux on the board.

Two or three times a year I run jumpers that are so fucked up I dare not even clean them out of fear of what will happen.. but that is rare.

 

[usrnm]

Do you really have to clean "no clean" flux? It is engineered to remain on the board and doesn't short components. Or is it for aesthetic reasons to present the board like it has never been repaired?

 

[mnaty]

I just like a clean board. Plus... The flux may be non-conductive and safe to leave behind, but the particles that may become stuck to it might not. Call me paranoid.