excess flux

RonDumas

New Member

• Aug 13, 2004

• #1

Is there a safe way to remove the excess flux that appears around a solder pad after soldering? I am soldering a relay board with 12 2pole relays and various chips and other parts. All is well however the back of the board is littered with small amounts of excess flux.
Any suggestions?

Thanks in advance for any help>>>

 

Nigel Goodwin

Super Moderator

Most Helpful Member

• Aug 13, 2004

• #2

RonDumas said:

Is there a safe way to remove the excess flux that appears around a solder pad after soldering? I am soldering a relay board with 12 2pole relays and various chips and other parts. All is well however the back of the board is littered with small amounts of excess flux.

Click to expand...

You can buy special solvents and scrub the board with a stiff bristled brush, I use a special aerosol at work which has an extension tube to a brush and trigger, I think it's made by MicroClean?.

Do you have any particular reason for wanting to remove the flux?.

 

RonDumas

New Member

• Aug 13, 2004

• #3

To be honest Nigel the board came out so good that is the only signs that it 's done by a hobbiest and not a factyory board. Probably not even noticeable by most but I know it's there.Thanks for the suggestion. I'll try the site you gave.

Also thanks for the time you put into your site and this forum. It's a huge help to guys like me..

 

J

Johnson777717

New Member

• Aug 13, 2004

• #4

I use Isopropyl Alchohol 90% with an acid brush (just a glorified paint brush with firm bristles). The main reason is because it is so cheap, and it'll disinfect any cuts that you might have on your fingers.

Using what Mr. Goodwin suggested is probably more effective, yet the alchohol is a suitable substitute if you're penny pinching.

 

jbeng

Member

• Aug 13, 2004

• #5

A plastic toothbrush also works well, just heat it up a couple of inches from the bristled end and bend it so that you don't destroy your knuckles while scrubbing. Also, make sure you get the 90+% isopropyl like Johnson said. The 70% stuff doesn't work very well. JB

 

zevon8

New Member

• Aug 13, 2004

• #6

Flux remover works great, only thing is you have relays on your PCB, and if they have plastic cases, they may not like it. You may also wash some of the residue into the relays unless they are the sealed "washable" kind, and cause yourself some grief.

Please, don't ask how I learned this, LOL

I have used Chemtronics "flux-off" for awhile now with good success, just get the right one, water soluable base or rosin base.

 

RonDumas

New Member

• Aug 13, 2004

• #7

Great ideas guys. Didn't realize it was that easy.
Thanks again..

By the way, I used dip sockets for the relays. It's really just a development board for now.