I'm trying to get rid of the flux on my board but it seems I have a problem. this is my board:



After soldering two memory under the board(as you can see two memory(a RAM and a Flash)), there is a bit flux among the pins and unfortunately under the plastic of the pin-headers. I have used a spray to wash it out but it doesn't good work for me. and I used a combo 50-50% alcohol and acetone but still...nothing!

Yesterday I was thinking that maybe boil water could help me. then I googled this "wash PCB with boiling water" and the first result was this. if you take a look in that page, you will see this comment:

Never use water soluble unless you are using a dishwasher to clean the boards. Found that out the hard way at a job years ago. Hot water is the only thing that will clean the flux off, not even alcohol. If you don’t clean it off the flux will eat at the solder connections turning them black and even chew through small leads. No clean is the way to go with a simple flux remover.

Ok, then this approach will work. but I have a few questions:

  1. Do you have any experince with this approach?
  2. Can boil water damage the PCB of the board? or some metal parts? and or some components like electrolytic capacitor?
  3. If in your opinion this is a good approach, How would you do it? for example, maybe this would be silly but I was thinking to put whole of the board inside of a bucket full of boil water and then shuck the board.
  • 1
    \$\begingroup\$ Sounds like a bad idea to me. What kind of flux are you using? \$\endgroup\$
    – Matt Young
    Commented Jan 4, 2015 at 16:14
  • \$\begingroup\$ @MattYoung Thanks Matt. Do you mean it is soluble in water or not? if so, I'm not sure. this is the brand of it: upload.tehran98.com/upme/uploads/e4c95db3b962599e1.jpg \$\endgroup\$
    – Roh
    Commented Jan 4, 2015 at 16:18
  • \$\begingroup\$ I would start by getting some different paste. A paste that doesn't even say what type of flux it uses is questionable at best. \$\endgroup\$
    – Matt Young
    Commented Jan 4, 2015 at 16:23
  • \$\begingroup\$ If you used rosin flux, then there is no problem. If you used water-soluable flux, then try cleaning carefully with clean water. Then next time use rosin flux. \$\endgroup\$ Commented Jan 4, 2015 at 16:30
  • 3
    \$\begingroup\$ Rosin flux is usually the most available. The problem with water-soluable flux is that it must be carefully cleaned off. Residue attracts moisture from the air and becomes conductive. I once saw a reset line pulled low with only a few 100 Ohms by water-soluable flux under a QFN package. Removing the package, cleaning the board, then resoldering with rosin flux fixed it. \$\endgroup\$ Commented Jan 4, 2015 at 16:50

1 Answer 1


Do youself a favor and get 1 gallon of flux remover. You can reuse it over and over again and as far as I know lasts for a very long time. Costs around $75

  • \$\begingroup\$ Doesn't answer the question. \$\endgroup\$
    – user2023
    Commented Feb 26, 2019 at 2:22

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