I am in need of new flux - Page 1
Forum section: electronics / general

author: PeterFW
author_rank: Frequent Contributor
timestamp: March 03, 2015, 10:09:05 pm
content: Hello!I know... another one of these...To answer the first questions, yes, i can use google, yes, i can use the forum search.Let me show you something.That is old and nasty rosin that once was in a tin i bought 15 years ago.I used to dunk my unregulated soldering iron in it and made the who tin bubble.About 10 years ago when i started soldering SMD and fine pitch stuff i forgot to order "good flux" and decidet that i will dissolve my old nasty rosin in isopronaol, strain it and put in in a syringe.This stuff looks horrible, reeks, but works extremely well.I have 10 year old TQFP boards soldered with this that still work perfectly.But you cant see annything after soldering, to inspect fine pitch joint under magnification.I have to clean the board every time with a toothbrush or let it soak. It gets cleaned after soldering either way but i would like to reduce the cleaning process to only once.All the fancy flux dispencer pens are filled with very volatile flux, at least all the videos on the net i have seen over the years make it look like it evaporates rather quickly.On the other side there are "paste flux" syringes, but paste is not all that great either i think.Is there anny flux out there that i can buy in europe, that has not an *insane* price (3 Euro per gram) and is a bit viscous?I am tempted to just buy 100g of new white rosin and make a new batch of my DIY flux without all the contaminants...Greetings,Peter

author: Balaur
author_rank: Unknown
timestamp: March 03, 2015, 10:21:51 pm
content: I like the CIF F42202 (~25€/30g syringe) gel flux and MG Chemicals Rosin Flux.Most of the time I reach for the Rosin Flux. It's slightly easier to clean but very sticky. The gel flux hardens a bit after soldering and it's a bit more difficult to clean everywhere. However, it's so satisfying to see the solder wetting everything.EDIT: Don't buy flux on eBay, as it's fake. However, the colophane/kofonium/rosin seems to be OK.

author: GreyWoolfe
author_rank: Unknown
timestamp: March 03, 2015, 11:54:41 pm
content: I also use the MG Chemicals Rosin flux. It's in a 2 oz squeeze bottle with a needle and stopper so it doesn't dry out.

author: nanofrog
author_rank: Super Contributor
timestamp: March 04, 2015, 02:13:54 am
content: Another vote forMG Chemicals Rosin 835.FWIW, I use needle bottles and brush pens to apply it.

author: marshallh
author_rank: Unknown
timestamp: March 04, 2015, 07:34:38 am
content: I also use the MG 835 in pen form (835-P).

author: Psi
author_rank: Super Contributor
timestamp: March 04, 2015, 07:52:02 am
content: i'm currently using CHIPQUIK SMD291 fluxhttp://www.digikey.com/product-detail/en/SMD291/SMD291-ND/355201.CHIPQUIK solder paste sucks for hand assembly, its too thick or the balls are too large, dunno. But the chipquick flux seems fine.For paste im using some Multicore/Loctite 63/37 paste which is great for hand assembly. it comes out of the syringe in a totally controllable fashion unlike chipquik.

author: Someone
author_rank: Super Contributor
timestamp: March 04, 2015, 09:02:35 am
content: Quote from: Psi on March 04, 2015, 07:52:02 amSecond vote for this easily available flux, I use it along with all sorts of solder compositions and it plays nicely but I find its all getting used up with the lead free solders that dont seem to have enough flux in them. Do you know of any lead free solders that come with enough flux in them already?

author: PeterFW
author_rank: Frequent Contributor
timestamp: March 04, 2015, 09:01:12 pm
content: Hello and thanks everybody for the reply!The CHIPQUIK is a bit on the "I will not pay that price due to moral reasons." side but the MG Chemicals look good!Sadly the only source i could find is about 20€ shipping, but... the MSDS of the stuff telle me what is in it.Ethanol, butan-2-ol and rosin... looks like i will be making my own batch again with some food grade rosin.Greetings,Peter

author: Balaur
author_rank: Unknown
timestamp: March 04, 2015, 09:07:41 pm
content: Quote from: PeterFW on March 04, 2015, 09:01:12 pmDon't forget a dash of Ballistol for good luck!

author: PeterFW
author_rank: Frequent Contributor
timestamp: March 04, 2015, 09:15:22 pm
content: Quote from: Balaur on March 04, 2015, 09:07:41 pmNo problem, i got at least a quart of a litre.Maybe i give it a good kick with a bit of break free CLP

author: zapta
author_rank: Super Contributor
timestamp: March 04, 2015, 09:35:33 pm
content: Quote from: PeterFW on March 04, 2015, 09:01:12 pm+1 for the chipquik tacky flux, and it will last forever.Alternatively you can try cheap ones from eBay. They will be better than the black stuff you are using now

author: nanofrog
author_rank: Super Contributor
timestamp: March 04, 2015, 09:58:14 pm
content: Quote from: PeterFW on March 04, 2015, 09:01:12 pmYou could always look for something from Stannol as well (I know Conrad carries it). Even if you have to make it, you could start with a 20gr. tin of Stannol Kolophonium (i.e. just add alcohol to thin it).As per getting MG Chemicals, perhaps a UK source might be worth a look (no idea if the shipping would be lower or not)?

author: Rasz
author_rank: Super Contributor
timestamp: March 05, 2015, 08:38:02 pm
content: gels are light years (hah) ahead of any rosin you might of ever used, soldering will be a new experiencequality stuff doesnt burn when touched by soldering iron like old time rosin, and stays liquid for a long time so you can simply wipe it with a piece of clothit might be slightly expensive for good ones, but it lasts a long time and makes life easier, or maybe you rather use that horse brush on all of your pcbs again?btw get a no clean flux, no one likes cleaning, and leaving it on will cause corrosion (its acid after all)

author: PeterFW
author_rank: Frequent Contributor
timestamp: March 05, 2015, 09:19:05 pm
content: Quote from: nanofrog on March 04, 2015, 09:58:14 pmThat was the UK sourceBut since the MG has only in it what i can stirr up myself im ok with makeing my own.Quote from: Rasz on March 05, 2015, 08:38:02 pmI clean my boards after soldering, even if they look clean. Some stray solder slatter ran ruin your day really fast. A bit of surface contamination that is not at all visible can ruin your µA hv voltage source output... i clean my boards every timeI have not seen rosin cause corrosion...But i guess i will submit and order a bit of paste flux, Edsyn or CHIPQUIK looks to be the thing to go for.Thanks everyone, all is sorted out now

author: Rasz
author_rank: Super Contributor
timestamp: March 06, 2015, 11:15:47 am
content: Quote from: PeterFW on March 05, 2015, 09:19:05 pmthey dont, its the modern stuff thats more aggressivehttp://www.circuitnet.com/experts/67321.shtmlmodern no clean fluxes have insignificant resin content (like 0.5% for example), or no resin at allget a clear liquid/gel no clean one, not brown crap/water soluble

author: ElectroNub
author_rank: Contributor
timestamp: March 06, 2015, 04:10:23 pm
content: I tried kingbo flux on a recommendation. I won't use anything else now. Simply using a good flux multiplied my soldering skill level by x10.It's not cheap. But you do get what you pay for.

author: wraper
author_rank: Unknown
timestamp: March 06, 2015, 10:00:43 pm
content: Kingbo is some strange Chinese beast. Xmoddz seem to be the only source of genuine one, if such exists at all as manufacturer is unknown. Every seller on ebay sells different flavor of it with different color and fume toxicity.