Have I bought the wrong solder - Page 1
Forum section: electronics / beginners

author: Potato
author_rank: Contributor
timestamp: July 26, 2016, 06:59:56 pm
content: I have just bought a couple of reels of solder. After having used 1mm lead free solder for ages, I thought I would try 60/40 in order to try amd improve the quality of my soldering.So I bought a reel of 0.5mm multicore 60/40, and a real of 0.71 mm 60/40. The 0.5mm is labelled as 5 core ersin flux (which I understand is good for general soldering) but the 0.71mm is labelled as X39 flux. Based on what I can find on the internet, X39 is intended for use on brass. Have I bought something that is inappropriate for general PCB soldering?

author: CJay
author_rank: Super Contributor
timestamp: July 26, 2016, 07:03:00 pm
content: It'll be fine, it's non corrosive, low/no residue.Just bear in mind you may need to lower the tip temperature of your iron.Practice makes perfect.

author: MarkF
author_rank: Super Contributor
timestamp: July 27, 2016, 12:52:33 am
content: The last solder I bought was Kester - 44 RA Solder Wire, .031" dia., Sn63Pb37.The transition between liquid and solid is very small. There aren't as many problems with cold solder joints due to movement. I like it better than the 60/40 solder. You might wish to try the 63/37 solder and save you 60/40 for less critical usages.

author: Audioguru
author_rank: Super Contributor
timestamp: July 27, 2016, 01:57:41 am
content: 60/40 solder is very old. It fails if the connection is wiggled when it cools. 63/37 is much better because it suddenly and quickly becomes very hard and movement of the parts do not bother it as much.Read links about solder in Google.

author: Monkeh
author_rank: Super Contributor
timestamp: July 27, 2016, 02:01:09 am
content: If your parts are wiggling that much, the type of solder is not your biggest concern.Seriously, all the 60/40 hate boggles the mind, it performs almost identically to 63/37 in practice.

author: GreyWoolfe
author_rank: Unknown
timestamp: July 27, 2016, 02:07:43 am
content: Quote from: Monkeh on July 27, 2016, 02:01:09 amNot a hater here, but I prefer the 63/37. I still have a little bit of 60/40 that I bought many years ago, it's thicker solder so it is relegated to soldering wire.

author: helius
author_rank: Super Contributor
timestamp: July 27, 2016, 02:51:49 am
content: Quote from: Potato on July 26, 2016, 06:59:56 pmNo, this is fine for PCB soldering. No-clean flux sometimes requires slightly higher temperatures to activate compared with rosin flux, but this should perform about the same as traditional RMA type.You can see that it passes all the IPC/Bellcore/etc standards for electronics use.http://www.farnell.com/datasheets/319747.pdfPlumbing fluxes that are unsuitable for electronics would never qualify as "halide free", because they are made of zinc or ammonium chloride.

author: Audioguru
author_rank: Super Contributor
timestamp: July 27, 2016, 03:39:32 am
content: I have 60/40 and 63/37 solders. I almost always use the 63/37 but lately it is almost gone so I use the 60/40 sometimes. There is a big difference. Today I needed to huff and puff on my 60/40 solder joint but it still was not hard. My 63/37 solder joint was solid instantly without blowing on it.

author: Monkeh
author_rank: Super Contributor
timestamp: July 27, 2016, 10:01:25 am
content: Quote from: Audioguru on July 27, 2016, 03:39:32 amWell if you're going to heat it to cherry red...There's only a few degrees difference in melting point.

author: CJay
author_rank: Super Contributor
timestamp: July 27, 2016, 11:13:19 am
content: Quote from: Monkeh on July 27, 2016, 10:01:25 amI agree with you, the 60/40 is my day to day stuff, works and works well for my needs, I read that there are issues with ROHS SMD components I believe as some of them fail when soldered with 60/40 (capacitors and end caps, I think it was to do with leaching of silver) but I've not personally seen failures I could attribute to that on my own equipment.I don't believe there's an awful lot of difference with any solder when it comes to requiring the components to be held stable, you'll make a nice dry joint with any of them if you waggle the component around while the solder is solidifying.Seems soldering is a mysterious dark art for many people which in itself mystifies me as I've always found it a very simple job.

author: Augustus
author_rank: Regular Contributor
timestamp: July 27, 2016, 11:25:36 am
content: Just use a name brand RMA type solder wire and it won't make any practical difference to your hand soldering whether you use the 60/40 or 63/37 alloy. As long as you stay away from the cheap no-name "brands" sold on eBay, Banggood or similar emarket places you will be fine.

author: nanofrog
author_rank: Super Contributor
timestamp: July 27, 2016, 08:24:04 pm
content: Quote from: Monkeh on July 27, 2016, 02:01:09 amFor leaded solder, I've 63/37 (my go-to), 60/40 (tinning wire), and 62/36/2 (silver & silver plated parts).So even though 60/40 isn't my favorite, I'm not a hater.

author: Potato
author_rank: Contributor
timestamp: July 27, 2016, 08:24:42 pm
content: Thanks for the advice , my soldering is certainly a lot better with the leaded solder.I have to say though, the range of different fluxes available seems to be the most confusing factor...multicore seem to have several options with no clear guidance on which is best for a basic pcb handsoldering application.

author: nanofrog
author_rank: Super Contributor
timestamp: July 28, 2016, 05:46:58 pm
content: Quote from: Potato on July 27, 2016, 08:24:42 pmFor hand soldering lead based alloys, the rosin based fluxes have been around for a long time, and are proven performers.Specifically, R, RMA, and RA (from least to most active; R = rosin only, RMA = rosin, mildly activated, and RA = rosin, activated). For a general purpose use (new to heavily oxidized), I'd recommend RA as it's safe and removes the most oxidation (they're all safe, but their ability to remove oxidation is what varies). BTW, the residues can be left on the board in most cases as well.There's also no-clean formulations (synthetic or highly refined rosin based resins), but I'm not as fond of them as they're harder to clean & the degree of activity can be harder to figure out IME (synthetic based in particular). YMMV however.

author: Potato
author_rank: Contributor
timestamp: July 30, 2016, 05:41:28 pm
content: Does anyone know what type (R, RMA, RA) the X39 flux that I mention in the first post is? Neither of the two solder reels I bought seem to indicate the type (despite them both being multicore branded, purchased from element14)Cheers

author: continuo
author_rank: Frequent Contributor
timestamp: July 30, 2016, 06:07:56 pm
content: X39 seems to be a "no clean" formula, based on modified rosins:http://amth.de/en/products/multicore-henkel/multicore-x39It's halide free and the performance should be comparable to "RMA" type fluxes, leaves probably less residues but these may be harder to clean off if you wish to remove them. Some of the "no clean" solder wires I've used had a bad habit to leave greyish-white, ugly looking residues after cleaning with IPA.

author: nanofrog
author_rank: Super Contributor
timestamp: July 31, 2016, 02:48:31 pm
content: Quote from: continuo on July 30, 2016, 06:07:56 pmFWIW, the modified rosin formulations are easier to clean than the synthetic resin based. Still harder to clean than rosin based IME, and as you mention, can leave a nasty white residue/solids behind (real bitch to get off). You might try adding a bit of xylene if you can (say ~20% by volume), or perhaps acetone (more aggressive than xylene; both can usually be found in painting supplies).BTW, the X39 is only 1% flux by weight, so will be more prone to needing additional flux.

author: R005T3r
author_rank: Frequent Contributor
timestamp: July 31, 2016, 06:42:35 pm
content: Quote from: continuo on July 30, 2016, 06:07:56 pmYes, actually you can use thinnerer to make it look good.

author: David Hess
author_rank: Super Contributor
timestamp: July 31, 2016, 07:42:43 pm
content: I hardly notice the difference between Sn60Pb40 and Sn63Pb37 when hand soldering but I think I get slightly cleaner results with the Sn63Pb37 for a given amount of effort.I only use the no clean fluxes with new parts and boards. For rework and anything else, I prefer the RA fluxes.

author: CJay
author_rank: Super Contributor
timestamp: August 01, 2016, 11:24:14 am
content: Something worth mentioning about using IPA to clean flux, IPA will absorb water from the atmosphere if it's in a bottle that can be opened (or in a pump action spray bottle)When you clean a board with IPA that's absorbed water it can leave behind a white residue or sheen which is difficult to remove.Best to use it from a pressurised aerosol can if you absolutely have to use IPA.Unless it's of the Brewdog Punk IPA variety, then I leave little to no residue.

author: David Hess
author_rank: Super Contributor
timestamp: August 02, 2016, 12:05:20 am
content: Quote from: CJay on August 01, 2016, 11:24:14 amDoes that explain why the old rosin flux thinner and cleaner was 50/50 IPA and toluene?I still have many bottles of it.