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DIY Stompboxes => Building your own stompbox => Topic started by: Kipper4 on December 30, 2012, 09:14:25 AM

Title: Flux remover
Post by: Kipper4 on December 30, 2012, 09:14:25 AM
Anybody got any good products for flux removal.
They seem really expensive to buy, has anyone got any homebrew suggestions?
Title: Re: Flux remover
Post by: Pyr0 on December 30, 2012, 09:28:02 AM
If you're in the uk you should be able to get Polycell Polyclens brush cleaner, that will work.
Title: Re: Flux remover
Post by: Dave W on December 30, 2012, 09:32:08 AM
Isopropyl alcohol and a toothbrush. Rinse and repeat as many times as necessary.
Title: Re: Flux remover
Post by: R O Tiree on December 30, 2012, 09:33:35 AM
I use acetone or pure methyl alcohol (not methylated spirits). Drizzle a bit on the board and then kind of "flick" it off with an old toothbrush. Repeat a couple more times and it's clean.
Title: Re: Flux remover
Post by: Kipper4 on December 30, 2012, 10:22:34 AM
thanks guys i'll try some of them.
I've got isopropyl alcohol for cleaning the R2R heads.
Title: Re: Flux remover
Post by: davent on December 30, 2012, 11:46:42 AM
Stainless steel dental pick followed by a small short bristled brush to clean off the flakes, no chemicals involved and you'll find a myriad of other uses for the dental pick.
Title: Re: Flux remover
Post by: Mike Burgundy on December 30, 2012, 11:54:59 AM
@ Mike: could you explain why methyl alcohol (methanol), and not methylated spirits (methanol+alcohol and possibly others such as isopropyl and acetone, etc, aka denatured alcohol)?
Title: Re: Flux remover
Post by: R O Tiree on December 30, 2012, 12:33:37 PM
Methylated spirits have oils added, which make them unpalateable (so pi$$-heads don't try to drink it, 'cos it makes you blind).
Title: Re: Flux remover
Post by: Vince_b on December 30, 2012, 12:54:33 PM
What are the negative effects of not removing flux residue from a pcb?
Title: Re: Flux remover
Post by: Seljer on December 30, 2012, 01:00:11 PM
Quote from: Vince_b on December 30, 2012, 12:54:33 PM
What are the negative effects of not removing flux residue from a pcb?

Flux tends to be slightly conductive, which usually makes the circuit emit a bunch of extraneous noise until you scrub it off the PCB
Title: Re: Flux remover
Post by: Vince_b on December 30, 2012, 01:04:02 PM
I never thought about that, from now on I will make sure to clean the board properly.
Title: Re: Flux remover
Post by: J0K3RX on December 30, 2012, 01:22:11 PM
If you ever use this you will never go back...Alpha Metals Pure Core is the BEST!!!

http://www.hisco.com/products/category/Soldering-Desoldering/Solder,-Wire/Water-Soluble

Most alcohols will make a gummy mess of flux... Back in the day we used trichloroethane and that stuff really cleans the boards but really dangerous stuff! Will get you high as a kite and probably kill your @ss if you are around it enough...   

Good stuff here
http://biochemsys.com/cleaning-technology-updates/printed-circuit-board-cleaning/
Title: Re: Flux remover
Post by: Mark Hammer on December 30, 2012, 04:01:36 PM
Quote from: Vince_b on December 30, 2012, 12:54:33 PM
What are the negative effects of not removing flux residue from a pcb?

The negative effect I most frequently come into contact with is that the shinyness of the flux can make it hard to visually inspect a board, to find solder bridges or other shorts, cold joints, and ragged or broken traces.  If I need to debug a board, one of the first things I do is clean the flux off, so that I can look it over accurately, and check all of those possibilities off my list.

I used to use isopropyl alchohol and a toothbrush.  Now I use methyl hydrate.  Yes, it isn't especially healthy, but it doesn't stink, and gets the job done VERY efficiently.
Title: Re: Flux remover
Post by: Ronan on December 30, 2012, 04:55:16 PM
Does anyone use naphtha as a flux remover? I was given a bottle by a telecommunications electrician but have never been game to try it on a populated pcb, for fear of damaging components. It also has a strong smell.
Title: Re: Flux remover
Post by: J0K3RX on December 30, 2012, 05:06:34 PM
Whatever you do DO NOT use bleach and ammonia!!! Geesh, nearly killed me...  :P
Title: Re: Flux remover
Post by: Kipper4 on December 30, 2012, 05:17:41 PM
I wouldnt have a clue where to get methenol.
I might be able to get the brush cleaner or acetete.
Thanks for all the suggestions.
anymore for anymore
Title: Re: Flux remover
Post by: Kipper4 on December 30, 2012, 05:24:23 PM
ok Thanks for the tip i will avoid bleach and ammonia.

Naphtha. I googled it and it turns out to be a by product of the petro chemical industry.
Wiki had this to say about it

"Common products made with it include lighter fluid, fuel for camp stoves, and some cleaning solvents."
Title: Re: Flux remover
Post by: Pyr0 on December 30, 2012, 05:32:12 PM
I use naphtha for degreasing enclosures prior to painting and also on PCB's prior to etching, great stuff. I find it works better than acetone.  It's just common lighter fluid.
Title: Re: Flux remover
Post by: pinkjimiphoton on December 30, 2012, 07:18:43 PM
Quote from: J0K3RX on December 30, 2012, 05:06:34 PM
Whatever you do DO NOT use bleach and ammonia!!! Geesh, nearly killed me...  :P

nothing like a little mustard gas, 'eh?

:icon_mrgreen:

you are EXTREMELY lucky. that particular combo has killed a lot of folks.
Title: Re: Flux remover
Post by: Mike Burgundy on December 31, 2012, 06:50:43 AM
Quote from: R O Tiree on December 30, 2012, 12:33:37 PM
Methylated spirits have oils added, which make them unpalateable (so pi$$-heads don't try to drink it, 'cos it makes you blind).
I knew they had add-ons for exactly that reason (solvents that are poisonous and/or taste *really* bad, sometimes coloring as a warning), although oils are an unknown to me. 'Course, there are many different blends out there. Stuff to light the BBQ with has a different set of design goals than something to sterilise medical tools with. The latter I feel is designed not to leave any residue. (Edit: hang on - I know a chemical engineer... Hope I remember to ask ;P )
Title: Re: Flux remover
Post by: Hobbyist on December 31, 2012, 06:55:49 AM
I like to use full-strength isopropol alcohol with acid brushes.  They are cheap and hold the fluid really well.  You can do a google search for "ATD 8235 ".

A good cleaning and a shot of conformal coating can make a nice presentation.
Title: Re: Flux remover
Post by: R O Tiree on December 31, 2012, 07:55:26 AM
I think you're right, Mike - a lot of different recipes out there. Some leave no oily residue, others seems to do so.
Title: Re: Flux remover
Post by: greaser_au on January 01, 2013, 03:17:14 AM
Isopropyl alcohol and a stiff brush was usually the weapon of choice  for  the first clean.   For final clean a  vapour phase cleaner is commonly used - a CFC was the solvent (this is before they were outlawed). Tri-nu (triclorethylene) was tested, but that just melted all the plastic parts.

I've used dichloromethane as solvent for cleaning boards by hand - but that is horrible stuff. Now also hard to get.

I suggest using either IPA or a commercially available PCB cleaner.  hold the board upright, solder side towards your scrubbing hand,  edge down. Initially wet a stiff brush and the board with the solvent & scrub to remove the hard stuff - this will leave a residue of sticky mess behind (if you use vero or protoboard it will get on the topside too :()  Then flush with clean IPA/solvent and a clean(ed) brush.  I wash the dirty liquid into absorbent paper towels, but you can also use a shallow tray, and pour some solvent in as a 'wash trough' - it all depends  how clean is 'clean enough'

david
Title: Re: Flux remover
Post by: Jdansti on January 01, 2013, 04:50:26 AM
Isopropanol and a brush for me.  90% works better than 70%.

Watch out for methanol. Use eye and respiratory protection and use gloves.  It's much more toxic than isopropanol. http://en.wikipedia.org/wiki/Methanol#Toxicity

General chemical hygiene:
Wash your hands after handling any chemicals including solder and flux.  Don't eat, drink, or smoke while soldering or working with chemicals.  Wash your hands before going to the bathroom (and after :) ). You'll know pretty quickly if you get ferric chloride on your pecker.  :icon_eek:
Title: Re: Flux remover
Post by: J0K3RX on January 01, 2013, 05:16:53 AM
I really don't see any reason to clean "no-clean" fluxes from most if not all stompbox PCB's unless you are pouring it on like pancake syrup? :icon_rolleyes:  Conformal coatings, why?  What a pain in the @ss!
Good read
http://www.assemblymag.com/articles/84286-why-clean-no-clean

If you want really shiny beautiful solder then use pure core! It doesn't cost that much and even if it does cost a little more than what you are using, you don't have to waste time and money on cleaners and scrubbing boards... just a little water and a paper towel and about 1 minute of your time and you will have shiny diamond like solder!
http://www.hisco.com/products/view/Soldering-Desoldering/Solder,-Wire/Water-Soluble/Alpha_W_30

btw - Trichloroethylene "triclor" is a cat 2 carcinogen (may cause cancer) and yes it "was" used to clean circuit boards years ago.
http://www.epa.gov/ttn/atw/hlthef/tri-ethy.html

ferric chloride on the pecker sounds like a pain in the dick :icon_eek:
Title: Re: Flux remover
Post by: igor12 on January 01, 2013, 06:32:22 AM
91% alcohol.  Denatured Alcohol works well also.  I let the board soak in it for an hour.  At work we have ultrasonic cleaner.  That works pretty good also.  Harbor freight has them cheap.  I bet hot water mixed with comet would work well also.
Title: Re: Flux remover
Post by: Kipper4 on January 01, 2013, 07:29:11 AM
comet?
what is that please?
Title: Re: Flux remover
Post by: greaser_au on January 01, 2013, 07:42:23 AM
Quote from: Kipper4 on January 01, 2013, 07:29:11 AM
comet?
what is that please?

Kipper4, 

We (UK and Aussies) would probably call it  Ajax...

david
Title: Re: Flux remover
Post by: Kipper4 on January 01, 2013, 08:11:20 AM
Gottya
thanks
elbow grease and an abrasive surface cleaner then lol
Title: Re: Flux remover
Post by: greaser_au on January 01, 2013, 08:16:46 AM
Quote from: J0K3RX on January 01, 2013, 05:16:53 AM
I really don't see any reason to clean "no-clean" fluxes from most if not all stompbox PCB's unless you are pouring it on like pancake syrup? :icon_rolleyes:  Conformal coatings, why?  What a pain in the @ss!

Agreed, hand made stompboxes are probably not a candidate for mandatory cleaning in any event, but it is a must for proper production-line QA.  And when machine soldering (in all but 100% surface mount where the flux is in the paste), we did apply flux like pancake syrup!   ;)  It's been over 20 years since I last racked a board, and I still clearly remember what that liquid flux and it's thinners smells like (it arrived in 5 litre bottles!).

I do like to see a nice clean board, though,  I think it shows care.  

Most stuff we made was conformal coated to protect it from humidity and airborne contaminants. I still do it for some things I build at home - I built an electric fence charger board a while back, it was intended to live outside in a sealed bucket,  I shot a coat of acrylic lacquer! Couldn't see myself doing it  for a stompbox (unless I had something to hide of course, then I'd use a nice thick black epoxy!!!)...

david
Title: Re: Flux remover
Post by: davent on January 01, 2013, 12:14:02 PM
Better living through chemistry?

Once the flux hardens it will pop off if encouraged with a hard, pointy object, no fumes, no residue, no shredded or saturated paper towel just a little bit of flakey flux dust to dry brush away.