Go Back   Home > Forums > >

Equipment & Tools From test equipment to hand tools

SMD soldering flux.
SMD soldering flux.
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 13th January 2021, 05:02 PM   #1
edbarx is offline edbarx  Europe
diyAudio Member
 
edbarx's Avatar
 
Join Date: May 2018
Location: Maltese Archipelago
Default SMD soldering flux.

What SMD soldering/desoldering flux do you use and suggest? I have watched YouTube videos by Louis Rossman doing literally next to impossible SMD desoldering/soldering work, but I have no idea what flux is used. I remember several years ago, I tried to repair an SMD PCB and failed miserably. The FLUX seems to be of paramount importance, and the internet is a nest of vipers ready to bite the innocent. The flux I ordered online was fake. It was much like wax used to steady components in old radios, rather than SMD flux!

SMD soldering would be a feat, but I am daunted by the thought alone!
__________________
Any fool can make things bigger, more complex, and more violent. It takes a touch of a genius, and a lot of courage, to move in the opposite direction. [Albert Einstein]
  Reply With Quote
Old 13th January 2021, 05:21 PM   #2
rayma is online now rayma  United States
diyAudio Member
 
Join Date: Apr 2011
Stay with major producers, like Kester. You can buy flux in small or large quantities. Use it liberally.
Solder Flux & Solder Flux Pens | Techni-Tool, Inc.
  Reply With Quote
Old 13th January 2021, 05:54 PM   #3
JMFahey is offline JMFahey  Argentina
diyAudio Member
 
JMFahey's Avatar
 
Join Date: Mar 2009
Location: Buenos Aires - Argentina
I always use simple homemade flux, just a "stone" of plain pine rosin, bought at the corner hardware store, inside an old jam jar and covered in alcohol which dissolves it in a few days.

I boight 1 kilo some 10 years ago, must have over 900 grams left.

Works like a charm, *bright shiny* solder joints every time.
__________________
Design/make/service musical stuff in Buenos Aires, Argentina, since 1969.
  Reply With Quote
Old 13th January 2021, 06:19 PM   #4
JonSnell Electronic is offline JonSnell Electronic  United Kingdom
diyAudio Member
 
JonSnell Electronic's Avatar
 
Join Date: Dec 2012
Location: The Jurassic Coast, England. GB
Amtech NC-559 is by far the best. Low mess residue and easy to whipe up with Isopropanol.
I put some from the 100g tub in a small syringe for accurate application.
__________________
Support for Fender, Marshall and all Valve Equipment; Audio Innovations, Audiorama FU29, Quad and Leak. www.jonsnell.co.uk
  Reply With Quote
Old 13th January 2021, 06:55 PM   #5
chris719 is online now chris719  United States
diyAudio Member
 
Join Date: Jun 2004
Location: Connecticut
SMD soldering flux.
I agree with the tacky flux in syringe recommendation, though I think I have some ChipQuik brand stuff.
  Reply With Quote
Old 13th January 2021, 07:54 PM   #6
Mark Tillotson is offline Mark Tillotson
diyAudio Member
 
Join Date: May 2018
Location: Cambridge UK
I've got 20g of "Termopasty", a Polish brand, comes in a little snuff tin as solid resin,
so for surface mount I scrape powder off the surface sometimes. But most of my SMT work
is toaster-oven reflowing of PCBs, for which I use ChipQuik lead-free no-clean solder paste SMD291SNL10 which comes in a handy 35ml syringe.
  Reply With Quote
Old 20th January 2021, 09:56 PM   #7
nigelwright7557 is online now nigelwright7557  United Kingdom
diyAudio Member
 
nigelwright7557's Avatar
 
Join Date: Apr 2008
Location: Carlisle, England
I find the "wax" type good at also sticking down pins as well as being a flux.
I sometimes put a dab behind the IC body to hold it to the pcb.
Trying to solder a wandering IC isnt much fun !

I have soldered pins down to 0.5mm pitch but it takes care and patience and a good eye for shorts/bridges.

For a QFP I put solder flux on all pads and a little behind where body goes to suck it down.
I then solder a couple of pins very gently.
I then check if it is still aligned and fix if not.
I can then drag solder other pins.
Finally drag solder over original pins that were soldered.
Next a good visual inspection for shorts.
I find with stubborn shorts add some flux, remove all solder from iron and drag iron away from pin and that usually fixed it.

The more you do it the better you get.
But use good quality solder not cheap rubbish that just blobs.
__________________
2021 versions of PCBCAD51 and PCBCAD720 out now >>> https://www.murtonpikesystems.co.uk
  Reply With Quote
Old 23rd January 2021, 06:07 AM   #8
H713 is offline H713  United States
diyAudio Member
 
H713's Avatar
 
Join Date: Nov 2017
Location: Madison WI
I've been using Kester 186 for a long time and it works fine, but cleanup is a mess.

FWIW, Louis Rossmann always recommends Amtech NC-559-V2-TF. I may try it at some point since the Kester 186 is unbelievably sticky and is difficult to clean.

The most potent flux I've ever used is Kester 2222. That stuff is fantastic. You do need to clean it off however, but it is water soluble. Unfortunately, I don't know of anywhere to buy it in small quantities.
  Reply With Quote
Old 24th January 2021, 05:24 AM   #9
ouimetnick is offline ouimetnick  United States
diyAudio Member
 
Join Date: May 2011
Location: Beverly, Massachusetts, USA
Send a message via AIM to ouimetnick SMD soldering flux.
I use Kester 186 at work and I hate it. It works well, but like you said, it's very sticky and annoying to clean. It cleans up well with Acetone, but we have to use a product called "Flux Off" it smells a bit like denatured alcohol and takes a bit of scrubbing.
  Reply With Quote
Old 24th January 2021, 06:07 AM   #10
suzyj is offline suzyj  Australia
diyAudio Member
 
suzyj's Avatar
 
Join Date: Jan 2006
Location: Western Australia
I make my own. It’s very easy. Mix pine rosin, Vaseline, a dab of isopropyl alcohol, and heat a little. You can dial in whatever consistency you desire. It’s the pine rosin that does all the heavy lifting in flux. Everything else is just to modify its consistency and stickiness.

See Suzy's Blog: Suzy's Super Rosin Paste Flux.
__________________
http://www.suzyj.net

Last edited by suzyj; 24th January 2021 at 06:10 AM.
  Reply With Quote

Reply


SMD soldering flux.Hide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
How do you remove flux residue after soldering? 777funk Construction Tips 43 22nd September 2015 11:05 AM
soldering flux? s214519 Equipment & Tools 14 21st July 2014 06:40 AM
Soldering rca's ends with wrong flux deriklfixit Construction Tips 14 26th July 2013 03:29 AM
What flux for soldering old brass? Pbassred Solid State 5 5th December 2007 11:35 AM
SMD soldering li_gangyi Everything Else 10 22nd November 2003 04:14 AM


New To Site? Need Help?

All times are GMT. The time now is 12:03 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki