Help me pick a flux/cleaner combination - Page 1
Forum section: electronics / general

author: John Coloccia
author_rank: Super Contributor
timestamp: July 08, 2013, 01:33:55 pm
content: I'm doing a lot of PCB solder work lately. Usually, I just use whatever flux is in my trusty Kester 44, and beyond that I have a no-clean flux pen. I really need to step up my game a bit, though. I'm doing all through hole soldering on PCB. I'm looking for a good flux/cleaner combination. I would like to stay solvent based as some components won't take kindly to being washed in warm water, and I like the convenience as well. I'm hoping that someone can give a specific recommendation to get me going on the right track. I guess ideally it would be a no-clean flux plus whatever solvent is required to remove the mess and make the boards pretty again.Thanks for any help!

author: ddavidebor
author_rank: Super Contributor
timestamp: July 08, 2013, 02:00:28 pm
content: The various degreaser and cleaner solvent work perfectly with all non water based flux

author: nanofrog
author_rank: Super Contributor
timestamp: July 08, 2013, 07:46:59 pm
content: Why not use Isopropyl Alcohol (99+%) to clean your existing Kester 44 flux (flux is rosin btw)?Some dental picks and ESD nylon brushes can work wonders on heavier deposits.

author: Pat Pending
author_rank: Regular Contributor
timestamp: July 08, 2013, 08:05:03 pm
content: In a pinch, coffee filters are a cheaper alternative to Kimwipes to absorb contaminated IPA run off.

author: John Coloccia
author_rank: Super Contributor
timestamp: July 08, 2013, 10:15:05 pm
content: I haven't found that IPA works particularly well for cleaning boards. Kester has appropriate fluxes and cleaners, but they're in pen form for hand soldering. I'd much prefer to have something I can put in a bottle with a brush.

author: peter.mitchell
author_rank: Super Contributor
timestamp: July 08, 2013, 11:07:54 pm
content: good 'ole acetone.

author: c4757p
author_rank: Super Contributor
timestamp: July 08, 2013, 11:12:57 pm
content: Quote from: peter.mitchell on July 08, 2013, 11:07:54 pmWith extreme care and knowledge of what kind of plastics are on the board.

author: ddavidebor
author_rank: Super Contributor
timestamp: July 08, 2013, 11:40:13 pm
content: Yep, acetone+electronic=melted caps

author: nanofrog
author_rank: Super Contributor
timestamp: July 08, 2013, 11:51:13 pm
content: Quote from: John Coloccia on July 08, 2013, 10:15:05 pmWhat % did you use?I ask, as I've not had issues with Kester rosin (44, 186, or 186-18) using 99+% IPA and a little elbow grease. You can also add some Xylene to make it a bit more aggressive (say 20% xylene, 80% IPA) for heavily deposited boards (can usually be found in home improvement or paint supply stores; not as aggressive as acetone to give you an idea).The 70% stuff from a drug store OTOH, is another matter (~ worthless in my experience, particularly due to other additives besides water).There are some commercially available flux cleaners that work very well of course, but they tend to be more expensive. If you'd prefer to go this route, take a look at Fluxclene by Electrolube. 1L container:http://www.midwesttech.com/marketplace/product_desc.asp?Sku=E11-FLU01L&category=

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 12:16:49 am
content: Quote from: ddavidebor on July 08, 2013, 11:40:13 pmI find acetone just nasty enough to remove flux as if it were magic, so I'll often install everything on a board that is not damaged by it, then use acetone to clean off the huge flux mess, then install the last few things (electrolytic caps, connectors, etc) and clean that with denatured alcohol.

author: John Coloccia
author_rank: Super Contributor
timestamp: July 09, 2013, 12:22:45 am
content: I'm using 95% IPA, which is about as high as you can distill IPA. The problem I find with IPA is that it tends to leave this sticky, icky film and never really gets all of it off. I want these things looking NICE because people are going to see them when they replace batteries and do things like that.FWIW, let this be a lesson to you...and me. ALWAYS read the damn data sheets. Looking through the datasheet for Kester 44, it says right there, use Kester 186 for flux. Piece of cake. I don't know what I was thinking.So I think between that, and one of the standard flux cleaners I should be OK. 186 is readily available in gallons, so I think I'm all set.

author: peter.mitchell
author_rank: Super Contributor
timestamp: July 09, 2013, 02:02:29 am
content: Quote from: c4757p on July 09, 2013, 12:16:49 amYeah, similar thing here, acetone will clear off most stuff like magic, i do notice though that i have no markings on resistors afterwards

author: nukie
author_rank: Frequent Contributor
timestamp: July 09, 2013, 06:22:58 am
content: Acetone leave white marks. Use IPA.Water based flux cleaner then rinse with H2O.

author: peter.mitchell
author_rank: Super Contributor
timestamp: July 10, 2013, 04:26:48 am
content: Quote from: nukie on July 09, 2013, 06:22:58 amAcetone *may* leave white marks, IPA, *may* leave a lot of flux.

author: c4757p
author_rank: Super Contributor
timestamp: July 10, 2013, 04:56:10 am
content: Quote from: peter.mitchell on July 09, 2013, 02:02:29 amI typically buy the most horrible, cheap-ass resistors I can find on eBay and it never washes off the markings! Both through-hole and SMD.Quote from: nukie on July 09, 2013, 06:22:58 amAs far as I can tell, acetone turns the flux residue white, so if it's leaving white marks, you're not getting it all off.