Badcaps.net Forum
Go Back   Badcaps Forums > Troubleshooting Hardware & Devices and Electronics Theory > Equipment Usage, Soldering, Techniques, and Reviews
Register FAQ Calendar Search Today's Posts Mark Forums Read

 
Thread Tools Display Modes
Old 05-18-2019, 01:03 PM   #1
Dannyx
CertifiedAxhole
 
Dannyx's Avatar
 
Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,396
Unhappy Does flux expire ?? Flux discussion.

Good day folks. Today I managed yet again to fail to fix a laptop board, which is actually beyond the point of this discussion, but it got me thinking about the flux I tried using: does flux expire or go bad in any way over time ? Stupid question, I know...

I've never been happy with any of the flux(es ?) I've used so far: whether at home or at my former shop, they all "vanish" pretty quickly once I start heating the part, leaving the area "dry", with nothing for the part to float in...this makes aligning QFNs an absolute misery and I hate it ! It seems to happen more with hot air rather than the iron...

I worked on this particular board at home, where I had a syringe of Amtech RMA-223-UV flux that's easily 10 years old, so I decided to use that because I had nothing better on hand. I think I bought it when I was in friggin' highschool It had turned a dark-brown color over the years from the original yellow of most fluxes, but I tried it anyway. It came out of the syringe alright and even seemed to flow nicely, but suffered from the same issue: as soon as I used my hot air nozzle, instead of the part flowing in place, the flux vanished but the chip just stood there....like a big middle finger >_>

Ironically, the flux Louis Rossmann uses is also Amtech, though a different kind, and his seems to stay liquid no matter how much he heats it up, which makes me think mine is either not the right kind or it's gone bad...

Then there's Kingbo...the guy at work who does reballings uses this stuff...don't know how good it would be for "manual" soldering...

I'm a noob at micro-soldering but I have to get my feet wet somehow, so I practice with what I have. Not spending 13 dollars on the same flux as Louis because it wouldn't see enough use to make it worth it - it may not sound like a huge amount, but it's a pretty penny to me. Cheers guys.
__________________
Wattevah...
Dannyx is offline   Reply With Quote
Old 05-18-2019, 01:35 PM   #2
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

flux absorbs moisture, so lifespan depends on how you store it.

btw, i like this - try it.
https://www.aliexpress.com/item/UANM...864986454.html
stj is offline   Reply With Quote
Old 05-18-2019, 01:57 PM   #3
Dannyx
CertifiedAxhole
 
Dannyx's Avatar
 
Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,396
Thumbs up Re: Does flux expire ?? Flux discussion.

Quote:
Originally Posted by stj View Post
flux absorbs moisture, so lifespan depends on how you store it.
Although it was in the original syringe with the cap still over the end, so theoretically pretty air-tight, it WAS out in a balcony all these years which tends to get pretty damp in the winters, so yeah...

Quote:
Originally Posted by stj View Post
Hmmm, I think I actually have that at work Never even opened it once. I have something similar at home left over from my grandpa who was a tech-whiz himself. As a kid, I used that extensively to tin stuff with: I'd dip the end of the wire into it and solder would stick beautifully to it, making soldering a joy. With the board now dead, I'll have something to try all these things on, starting with this ancient 30 year-old solder paste which I remember leaving a greasy, oily residue even when heated at full blast with my soldering GUN, so it might actually stay liquid under hot air and not evaporate

Last edited by Dannyx; 05-18-2019 at 02:53 PM..
Dannyx is offline   Reply With Quote
Old 05-18-2019, 02:51 PM   #4
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

it's not a liquid, it's a gell/cream.
and yes, it melts like a thick grease and does not evaporate.

Last edited by stj; 05-18-2019 at 02:52 PM..
stj is offline   Reply With Quote
Old 05-18-2019, 02:54 PM   #5
Dannyx
CertifiedAxhole
 
Dannyx's Avatar
 
Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,396
Default Re: Does flux expire ?? Flux discussion.

Quote:
Originally Posted by stj View Post
it's not a liquid, it's a gell/cream.
and yes, it melts like a thick grease and does not evaporate.
No arguing with that When you heat it up it become more fluid. It's best when it actually stays runny like that instead of burning and disappearing.
Dannyx is offline   Reply With Quote
Old 05-18-2019, 03:46 PM   #6
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

i use it for tinning tracks and desoldering corroded chips - it stays until you clean it off.
stj is offline   Reply With Quote
Old 05-18-2019, 09:10 PM   #7
llonen
Badcaps Veteran
 
Join Date: Sep 2014
City & State: united kingdom
My Country: hampshire
Line Voltage: 240 VAC 50Hz / 110 VAC 50 Hz and 415 VAC 50Hz
I'm a: Professional Tech
Posts: 356
Default Re: Does flux expire ?? Flux discussion.

I use what I believe to be Amtech RMA-223 or at least that is what it said on the order I find it stays around for quite some time during heat application and it finds use for all my smd rework. I order a bulk amount at a time and store the unopened in a fridge, I do have a 5 litre container of liquid flux that I rescued from an old electronics factory i used to work at now that has to be at least 20 years old and was made by frys metals (Uk manufacturer).

It seems good for work other than SMD or at least anything that does not require it to stay around too long as it soon evaporates and and the carrier solvent is nasty to work with if you don't have fume extraction. I must admit to mostly going over to gel / cream flux's now even for stuff that really does not require this.
llonen is offline   Reply With Quote
Old 05-19-2019, 02:01 AM   #8
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

there are 2 amtech 223's with different letters on the end.
stj is offline   Reply With Quote
Old 05-19-2019, 02:53 AM   #9
Dannyx
CertifiedAxhole
 
Dannyx's Avatar
 
Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,396
Default Re: Does flux expire ?? Flux discussion.

Quote:
Originally Posted by stj View Post
there are 2 amtech 223's with different letters on the end.
Mine says UV.
Dannyx is offline   Reply With Quote
Old 05-19-2019, 05:05 AM   #10
Agent24
I see dead caps
 
Agent24's Avatar
 
Join Date: Oct 2007
City & State: Hiding inside a plated-through hole
My Country: New Zealand
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 4,600
Default Re: Does flux expire ?? Flux discussion.

Quote:
Originally Posted by stj View Post
flux absorbs moisture, so lifespan depends on how you store it.

btw, i like this - try it.
https://www.aliexpress.com/item/UANM...864986454.html
I also have some of that cheap eBay paste flux, and it is indeed quite good.
Mine came in a plastic tub. I've had it for years, it doesn't seem to have gone off yet.
__________________
"Tantalum for the brave, Solid Aluminium for the wise, Wet Electrolytic for the adventurous"
-David VanHorn
Agent24 is offline   Reply With Quote
Old 05-19-2019, 10:15 AM   #11
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

yours may be different, i tried lots.
that one in the tin is water-clear and amber coloured.
the more common ones look like yellow tinted animal fat!!! (and probably are - or based on something similar)
stj is offline   Reply With Quote
Old 05-19-2019, 11:14 AM   #12
TacoLoco
New Member
 
Join Date: May 2019
City & State: cdmx
My Country: mexico
I'm a: Knowledge Seeker
Posts: 16
Default Re: Does flux expire ?? Flux discussion.

Quote:
Originally Posted by Dannyx View Post
Ironically, the flux Louis Rossmann uses is also Amtech, though a different kind, and his seems to stay liquid no matter how much he heats it up, which makes me think mine is either not the right kind or it's gone bad...
yeah, roosmann flux always stays there no matter what and sometimes he even puts more flux and you can see the circuits and stuff drowning in flux that behaves like gel, water or something.

I can't get amtech flux at decent price in my country and the cheap ones dry out soon as you put the iron in the pad, almost immediately, leaving sticky residue, i wish i could get my hands in some of that nice stuff that louis has.
TacoLoco is offline   Reply With Quote
Old 05-19-2019, 11:17 AM   #13
Dannyx
CertifiedAxhole
 
Dannyx's Avatar
 
Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 2,396
Default Re: Does flux expire ?? Flux discussion.

I DID find it locally, or at least on a website which ships to our country at a decent price, but it's still too expensive to be worth buying only for occasional use. A repair center could definitely afford it though, so I'll try convincing my boss to get me a syringe of that stuff just to see how well it behaves, so fingers crossed
Dannyx is offline   Reply With Quote
Old 05-19-2019, 02:41 PM   #14
diif
Badcaps Veteran
 
Join Date: Feb 2014
City & State: Midlands
My Country: England
I'm a: Professional Tech
Posts: 4,036
Default Re: Does flux expire ?? Flux discussion.

Rossmann uses 599. It awesome stuff. Not the cheapest but then a 30cc tube will long time. Unless you're Rossmann that is. There's loads of fakes about. The genuine stuff smells sweet and nice not that it should be smelled.
diif is offline   Reply With Quote
Old 05-19-2019, 04:41 PM   #15
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

he has sacks of it!!
https://www.youtube.com/watch?v=MpPvy4qyHg4
stj is offline   Reply With Quote
Old 05-19-2019, 05:47 PM   #16
Agent24
I see dead caps
 
Agent24's Avatar
 
Join Date: Oct 2007
City & State: Hiding inside a plated-through hole
My Country: New Zealand
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 4,600
Default Re: Does flux expire ?? Flux discussion.

Quote:
Originally Posted by stj View Post
yours may be different, i tried lots.
that one in the tin is water-clear and amber coloured.
the more common ones look like yellow tinted animal fat!!! (and probably are - or based on something similar)
Not sure what you mean by "water-clear and amber coloured"? It's either one or the other, surely?

Mine smells like flux and acts like it, and works pretty well.
Attached Images
File Type: jpg Soldering Paste.jpg (604.4 KB, 17 views)
File Type: jpg Soldering Paste Open.jpg (575.7 KB, 15 views)

Last edited by Agent24; 05-19-2019 at 05:55 PM..
Agent24 is offline   Reply With Quote
Old 05-19-2019, 06:50 PM   #17
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

water-clear as opposed to being "foggy" like yours
stj is offline   Reply With Quote
Old 05-19-2019, 07:08 PM   #18
Agent24
I see dead caps
 
Agent24's Avatar
 
Join Date: Oct 2007
City & State: Hiding inside a plated-through hole
My Country: New Zealand
Line Voltage: 230VAC 50Hz
I'm a: Hobbyist Tech
Posts: 4,600
Default Re: Does flux expire ?? Flux discussion.

Quote:
Originally Posted by stj View Post
water-clear as opposed to being "foggy" like yours
Ah right. So mine's the pork lard then?
Agent24 is offline   Reply With Quote
Old 05-19-2019, 09:50 PM   #19
stj
Great Sage 齊天大聖
 
stj's Avatar
 
Join Date: Dec 2009
City & State: Europe
My Country: some shithole run by Israeli agents
I'm a: Professional Tech
Posts: 20,876
Default Re: Does flux expire ?? Flux discussion.

yes, and mine is like beer jello
stj is offline   Reply With Quote
Old 05-20-2019, 02:23 AM   #20
llonen
Badcaps Veteran
 
Join Date: Sep 2014
City & State: united kingdom
My Country: hampshire
Line Voltage: 240 VAC 50Hz / 110 VAC 50 Hz and 415 VAC 50Hz
I'm a: Professional Tech
Posts: 356
Default Re: Does flux expire ?? Flux discussion.

Pork lard, lmfao you know I cant un-see that now. I might try the refined 559 pork lard lard but the regular 'animal fat' 223 works exceptionally well for me even if it is a knock off 'cow fat' which it probably is. By the way are there any vegetarian options, and please remember not to lick the fat off your pcbs even if it tastes nice. Oh I looked at the Fry's metals flux its an R8 flux the date code for which well most of the label has long disintegrated and that looks like what I imagine industrial vinegar might look like. It is no longer made, well in that formulation and has to be be in excess of 30 years old, I would not classify that as no clean it definitely needs cleaning.

Last edited by llonen; 05-20-2019 at 02:36 AM..
llonen is offline   Reply With Quote
Reply

Thread Tools
Display Modes

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



Badcaps.net Technical Forums 2003 - 2019
Powered by vBulletin ®
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.
All times are GMT -6. The time now is 12:02 AM.
Did you find this forum helpful?