How do you typically Clean flux from PCB

[ThatDude]

Hello, I’ve been trying to find the best method for cleaning flux off a PCB. Here is what I have been doing recently: I take an alcohol based contact and electronics cleaner and spray and scrub the PCB after I have populated it with most of the components (except the pots, switches or anything that mounts to the opposite side of the board). This leaves the board pretty clean on the side I’ve been soldering on, but the residue that I cleaned from the other side sort of collects on the component side and makes it fluxy and sticky. It’s really tough to clean this side because of the components in the way. So I am looking for recommendations on how others clean the flux off PCB’s. In the pic you can see the flux residue on the component side of the board that was hard to clean off.

P.S. - if you think cleaning flux off a board is a waste of time, let me know that too. Maybe I am just doing too much.

 

[eatkinola]

Thread 'Basic Workflow Tips for Building a PedalPCB'

Sep 9, 2019

Hello! This is my method for building a PedalPCB from start to finish. Is it the right way? Not necessarily. It's just what works for me and I hope it sheds some light on certain steps in the process along the way. I created this as a reference guide for anyone to use if needed. Thanks for reading!

Step 1: Drill the enclosure.
I recommend having this done before starting any soldering as it makes test fitting the fully populated board a whole lot easier later.
fig. 1


*Key step* Always print the drill template at 100%. Some printers default to "fit to page". You...

• Jovi Bon Kenobi
• Replies: 122
• Forum: General Questions

• 
• 

Try this method with IPA-soaked chem wipe. It grabs the flux instead of just pushing it around with toothbrush. I've had good success with this. After 1-2 times with a soaked chemwipe, I'll make one pass with IPA and toothbrush without a chemwipe. Clean as a whistle. If there is any residue on the component side, I use a small soaked wipe pushed around with a chopstick.

 

[ThatDude]

Thread 'Basic Workflow Tips for Building a PedalPCB'

Sep 9, 2019

Hello! This is my method for building a PedalPCB from start to finish. Is it the right way? Not necessarily. It's just what works for me and I hope it sheds some light on certain steps in the process along the way. I created this as a reference guide for anyone to use if needed. Thanks for reading!

Step 1: Drill the enclosure.
I recommend having this done before starting any soldering as it makes test fitting the fully populated board a whole lot easier later.
fig. 1


*Key step* Always print the drill template at 100%. Some printers default to "fit to page". You...

• Jovi Bon Kenobi
• Replies: 122
• Forum: General Questions

• 
• 

Try this method with IPA-soaked chem wipe. It grabs the flux instead of just pushing it around with toothbrush. I've had good success with this. After 1-2 times with a soaked chemwipe, I'll make one pass with IPA and toothbrush without a chemwipe. Clean as a whistle. If there is any residue on the component side, I use a small soaked wipe pushed around with a chopstick.

I’ll try the soaked chem wipe method. It sounds like it might solve the issue of pushing flux from the heavily soldered side that I am having. Thank you!

 

[jwin615]

These and a denture brush from the dollar store.

https://a.aliexpress.com/_mrYfSAG

Also, it depends on the type of flux/solder. Kester 245, no clean solder for instance, states in the datasheet that ipa won't remove the flux. it says the same about the Kester 44 that I've used for close to 20 years. And ipa doesn't do a great job at all. Ipa followed by a touch of acetone and a scrub with water does good enough for me.
There's water soluble rosin core but it has a limited shelf
I would check the datasheet for your solder and see what it says.
There are also diy recipes out there for flux cleaner. Something like 85/10/5 ipa/acetone/H202 but I'm probably wrong on the measurements. I'll get around to trying it one day.

 

[tegendemuur]

Thread 'Basic Workflow Tips for Building a PedalPCB'

Sep 9, 2019

Hello! This is my method for building a PedalPCB from start to finish. Is it the right way? Not necessarily. It's just what works for me and I hope it sheds some light on certain steps in the process along the way. I created this as a reference guide for anyone to use if needed. Thanks for reading!

Step 1: Drill the enclosure.
I recommend having this done before starting any soldering as it makes test fitting the fully populated board a whole lot easier later.
fig. 1


*Key step* Always print the drill template at 100%. Some printers default to "fit to page". You...

• Jovi Bon Kenobi
• Replies: 122
• Forum: General Questions

• 
• 

Try this method with IPA-soaked chem wipe. It grabs the flux instead of just pushing it around with toothbrush. I've had good success with this. After 1-2 times with a soaked chemwipe, I'll make one pass with IPA and toothbrush without a chemwipe. Clean as a whistle. If there is any residue on the component side, I use a small soaked wipe pushed around with a chopstick.

This is like the IPA wipes used to clean items going into the cleanroom, right?

 

[PunchySunshine]

I like to chip off the larger bits of flux GENTLY with a flat head screwdriver. Then hit with kimwipes and IPA. Then the final brush down.

 

[Zanshin]

I use Kester 331 (water soluble) for everything that can get wet (most things), and wash the board with warm water and a toothbrush. It’ll be clean as a whistle.

For the final parts/assembly I switch to Kester 245 (no clean).

 

[eatkinola]

This is like the IPA wipes used to clean items going into the cleanroom, right?

Isopropyl alcohol 91% from the drug store

Then hit with kimwipes and IPA.

Yeah these kimwipes! I was misspelling it.

 

[fontoponto]

I did not do it for years then I tried it a few times with isopropyl alcohol 99,9% and a soft toothbrush but it turned out that I scratched the silkscreen somehow.... So I will not do it anymore

 

[Nic]

I did not do it for years then I tried it a few times with isopropyl alcohol 99,9% and a soft toothbrush but it turned out that I scratched the silkscreen somehow.... So I will not do it anymore

Same thing happens to me, I was wondering if my iron might be too hot and that would cause the silkscreen to flake when using the toothbrush...

 

[Big Monk]

The best way to start if to use a good, lower flux solder.

One of the things I stopped doing when I started selling pedals was insane flux cleaning.

I will dry scrape stuff off the top but I don’t fuck around with the bottom anymore.

 

[Harry Klippton]

I use MG Chemicals flux remover. It's mostly acetone

 

[VanWhy]

I like to use the MG Chemicals remover as well Amazon Link

Scrub it with anti-static brushes Amazon Link 2

Then finish it off with IPA and a separate brush.

It's pricey and probably not worth it but it does look good and helps if I need to troubleshoot.

 

[Harry Klippton]

I like to use the MG Chemicals remover as well Amazon Link

Scrub it with anti-static brushes Amazon Link 2

Then finish it off with IPA and a separate brush.

It's pricey and probably not worth it but it does look good and helps if I need to troubleshoot.

Anti static brush, nice

 

[fontoponto]

Same thing happens to me, I was wondering if my iron might be too hot and that would cause the silkscreen to flake when using the toothbrush...

I had this on areas where no solder tip touched the silk screen. Maybe the toothbrush wasn't that soft...

 

[Erik S]

I use MG Chemicals flux remover. It's mostly acetone

I use that MG stuff too, but just based on the smell I thought it was mostly alcohol.

 

[KR Sound]

I like to use the MG Chemicals remover as well Amazon Link

Scrub it with anti-static brushes Amazon Link 2

Then finish it off with IPA and a separate brush.

It's pricey and probably not worth it but it does look good and helps if I need to troubleshoot.

This is the way and totally worth it. But I just use a toothbrush I got at the veterinary

 

[Erik S]

You only need to clean em if you're gonna post troubleshooting threads.

 

[Erik S]

Or build reports.

 

[Harry Klippton]

I use that MG stuff too, but just based on the smell I thought it was mostly alcohol.

My memory is pretty faulty lately but I think I checked the msds?