Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Flux Remover

Status
Not open for further replies.

bryan

Member
Hello:

Anybody have any recommendations for flux remover. I see MG Chemcials makes a number of products in this category. Any suggestions for the DIY hobbyist.?
 
Why do you need to remove the flux? Many years ago I saw an H-P field service bulletin (Yes, in the days of real H-P field service.) that said unless a repaired PCB could be cleaned completely (as in the factory process) the flux on repaired solder connections should be left in place. Attempts to dissolve and remove the flux would more likely spread contamination around and under other components.

Ken
 
Bryan it's impossible to answer your question unless you tell us what kind of flux you're trying to remove, although KMoffett does bring up a good point, something like the rosin core flux of typical solders doesn't need to be removed. Some acidic fluxes need to be cleaned but that's typically done with water or a mild solvent like alcohol, depends on the specific flux in question.
 
I'll assume you're using rosin flux like most of us most of the time. Just use a mixture of 50% denatured ethanol, 40% isopropyl alcohol and 10% acetone. You can get the ethanol and acetone at any home improvement or paint store and 99% isopropyl alcohol at some drug stores. You have to look around to see who has the good stuff. The last time I found it was at Safeway. As with all flux removers that contain acetone, this is not safe on styrene, ABS or polycarbonate. If you have questionable plastics attached to the PCB, just use the alcohol mixture alone.
 
Last edited:
Again though, if it's standard rosin core flux, there is no reason to remove it.
 
I remove flux to prevent atmospheric moisture from having a wicking material, to improve inspectability and because it's a sign of good workmanship. The O.P. may have his own reasons to deflux which I will consider sufficient without knowing them. He asked for flux remover suggestions so I gave them.

In industry, IPC J-STD-001E requires removal of any visible residue from R, RA or RMA fluxes.
 
Last edited:
I have tried all the over-the-counter flux removal remedies discussed above plus some others and wasn't happy with the results from any of them. I finally broke down and bought a spray can of Techspray Flux Remover. What a huge difference. Even though it's more expensive than the over-the-counter chemicals, it is so superior that it's not even funny.

creakndale
 
Most of the really good flux removers used to have chlorinated and fluorinated solvents that were many times more effective than the new ones. Environmental and health regulations have forced or are forcing the manufacturers to reformulate them into weak and pitiful products.
 
Hi,

I dont always remove the rosin core flux, but when i do i use Dos Equis :)

Ok seriously now, when i do have to remove it i use 70 percent isoprop alcohol and it works fine. Sometimes the board needs a protective spray coating afterwords. Long time ago i used something else more recommended, but cant remember the name now, oh yeah, carbon tetrachloride. We used one of those little bottles with the spring top where you push down on it with the brush and it dispenses liquid right into the brush tip.
 
Last edited:
Do you mean carbon tetrachloride? That's very nasty stuff.
Yeah...but a solvent to die for! Both figuratively and literally. :)

Ken
 
Thanks all..I always thought it was necessary and good practise to remove flux after soldering. I am referring to the rosin core. Just started applying a coliform coating to my boards so thought it would be good practise to remove the flux first.

Have used Isopropyl alchohol before and seems to work. Think i will try the "recipe" by K6JEAD.
 
Only if you huff it KJ6EAD. As with any industrial chemicals proper use and precautions are key to safe use. Regardless of how 'nasty' it is, it still works incredibly well for what it does.
 
Just started applying a coliform coating to my boards so thought it would be good practise to remove the flux first.
Why? And what is a coliform coating?
 
Hi,

I dont always remove the rosin core flux, but when i do i use Dos Equis :)
Mr Al... My hat is off to you, I cried tears of laughter from that.
 
See, now you actually have a 'why' =)
 
I believe carbon tetrachloride was used as a component of R-11 refrigerant. Supposedly extremely toxic to the liver or the kidneys, can't remember which.
 
Status
Not open for further replies.

Latest threads

Back
Top