The best solder for electronics - Page 1
Forum section: electronics / beginners

author: DiegoBrown
author_rank: Newbie
timestamp: July 04, 2019, 09:06:34 pm
content: Hi! What is the best solder for electronics? Somebody know?

author: magic
author_rank: Super Contributor
timestamp: July 04, 2019, 09:12:05 pm
content: 0.7mm diameter Sn60Pb40 with rosin core

author: Audioguru
author_rank: Super Contributor
timestamp: July 05, 2019, 02:10:38 am
content: 60/40 solder was used a long time ago and if the connection is moved as it cools then it forms a bad solder joint. Electronics assembly today uses lead-free or 63/37 Sn-Pb. 63/37 solidifies immediately and makes very good joints. The solders have a flux core.

author: rfengg
author_rank: Regular Contributor
timestamp: July 05, 2019, 02:59:24 am
content: I bought a roll of the Kester 24-6337-8800 50 Activated Rosin Cored Wire Solder Roll, 245 No-Clean, 63/37 Alloy, 0.031" Diameter (https://www.amazon.com/gp/product/B00068IJOU/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) and was thrilled with the results.A tab bit expensive but well worth it for me.

author: 0culus
author_rank: Super Contributor
timestamp: July 05, 2019, 03:20:15 am
content: Kester 67/37 is my favorite.

author: bdunham7
author_rank: Super Contributor
timestamp: July 05, 2019, 04:26:50 am
content: https://www.amazon.com/gp/product/B00068IJWC/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1You may prefer a larger diameter, but this works for me. I have 10-15 rolls of solder around, but unless I have something big or that needs silver or lead free, this is the one.

author: tooki
author_rank: Super Contributor
timestamp: July 05, 2019, 05:28:11 am
content: Quote from: DiegoBrown on July 04, 2019, 09:06:34 pmNo, nobody knows anything about it. And I’m sure it’s never been discussed here before...What I’m trying to say is, do a little search, this is a topic that’s been discussed extensively, even recently, so rather than start a new discussion, try looking for those threads and then just ask whatever isn’t adequately addressed already.

author: MarkF
author_rank: Super Contributor
timestamp: July 05, 2019, 05:36:23 am
content: I have been using the Kester 63/37 because of its abrupt change from liquid to solid (all 63/37 mixes).I think its 0.031" diameter. Good over all diameter. Might be just a little big for SMD parts.I just posted this comparison a few weeks ago:

author: tooki
author_rank: Super Contributor
timestamp: July 05, 2019, 09:21:32 am
content: Quote from: MarkF on July 05, 2019, 05:36:23 amThat's my "daily driver" solder, too. Excellent stuff in absolute terms, and at a good price, too. I will probably pick up a reel of the .020" at some point. Or maybe of the Sn62Pb36Ag2, even.I have a reel of .015" Kester 63/37 with282 water-whiteRMA flux that I got from a surplus mail order back around 1990. (Turns out this is quite expensive solder that costs around $200 a reel at normal price!) It works well for SMD, if I don't just decide to drag solder.

author: HighVoltage
author_rank: Super Contributor
timestamp: July 05, 2019, 09:27:48 am
content: Kester 63/37 is my preferred choice as well. Once you get used to it, you never want to use anything else.

author: NivagSwerdna
author_rank: Super Contributor
timestamp: July 05, 2019, 09:28:54 am
content: It depends on the amount of work you do... I do small quantities only and love myhttps://uk.farnell.com/edsyn/su35100/solder-wire-62-36-2-183-deg-100g/dp/871394It's 0.35mm Sn62Pb36Ag2 (0.014" in old money)OP DiegoBrown has 1 Post; Welcome

author: Monkeh
author_rank: Super Contributor
timestamp: July 05, 2019, 09:39:47 am
content: Quote from: Audioguru on July 05, 2019, 02:10:38 am60/40 is readily available and used today and causes no problems.

author: tooki
author_rank: Super Contributor
timestamp: July 05, 2019, 11:00:38 am
content: Quote from: Monkeh on July 05, 2019, 09:39:47 amBut 63/37 is superior and is only trivially more expensive, so for the hobbyist, I see no reason to use 60/40, which is noticeably more sensitive to movement during solidification, producing what's called a "disturbed joint".

author: magic
author_rank: Super Contributor
timestamp: July 05, 2019, 11:46:21 am
content: You guys are nuts with that eutectic obsessionI for one actually like Pb-free because it is very easy to remove from PCB in its "paste" phase. No wicking, no sucking, it just comes off.I don't use it mainly because of higher temperature and out of worry about whiskers.

author: kosine
author_rank: Regular Contributor
timestamp: July 05, 2019, 11:51:57 am
content: Yes, the 63/37 alloy is known as eutectic ("melts well" in Greek). Basically means it has a single melting/freezing point rather than being semi-molten over a range of temperatures.There are other alloys with similar properties.https://fctsolder.com/eutectic-solder/60/40 isn't that much worse, and the cheaper varieties probably aren't exactly 60/40 in any case.Personally, I've always found the thickness of the solder wire to be more important. The thinner stuff seems easier to work with for most components. As long as it contains flux - though a flux pen makes things much easier in any case.

author: Psi
author_rank: Super Contributor
timestamp: July 05, 2019, 11:55:50 am
content: +1 for Kester 67/37 flux type 285 (mildly activated rosin flux classified as Type ROL0)But it's not the cheapest.I like having two thicknesses on hand.Thick - 0.7 or 0.8mm (wires / big parts)Thin - 0.3 or 0.4 mm (Small SMT)

author: tooki
author_rank: Super Contributor
timestamp: July 05, 2019, 11:14:07 pm
content: Quote from: magic on July 05, 2019, 11:46:21 amIt's not an "obsession" to have a preference for the superior product, especially when the added cost is truly insignificant.

author: bd139
author_rank: Super Contributor
timestamp: July 05, 2019, 11:24:06 pm
content: Felder 62/36/2. Eutectic silver bearing joy that stuff is.

author: Monkeh
author_rank: Super Contributor
timestamp: July 06, 2019, 12:36:58 am
content: Quote from: tooki on July 05, 2019, 11:14:07 pmThat very much depends on your relative availability..Pretty much the same solder I use daily:https://uk.farnell.com/multicore-loctite/3096525-m/solder-wire-60-40-180-deg-250g/dp/5090787A eutectic (not 63/37 because they don't stock it..) equivalent:https://uk.farnell.com/multicore-loctite/dlmp24-250g-reel/solder-wire-lmp-0-56mm-250g/dp/419552Truly insignificant, merely 50% more for 2% better solder.

author: 0culus
author_rank: Super Contributor
timestamp: July 06, 2019, 12:45:54 am
content: I'd say having a clear state transition point is worth more than 2%.

author: Monkeh
author_rank: Super Contributor
timestamp: July 06, 2019, 12:52:31 am
content: Quote from: 0culus on July 06, 2019, 12:45:54 am15 years of soldering with all alloys, well.. stop soldering on a motel bed.

author: M4trix
author_rank: Frequent Contributor
timestamp: July 06, 2019, 12:53:11 am
content: Quote from: magic on July 05, 2019, 11:46:21 am

author: mrpackethead
author_rank: Super Contributor
timestamp: July 06, 2019, 01:57:25 am
content: Quote from: magic on July 05, 2019, 11:46:21 amIF you are worried about whiskers when using Pb Free Solder, then dont' use a Pure Tin plated PCB. But that has'tn been really done for years. ENIG, or HASL finish, and you wont' get whiskers.

author: mrpackethead
author_rank: Super Contributor
timestamp: July 06, 2019, 01:58:28 am
content: The real answer is 'it depends'. Theres a reason why there are many different types of solder. Theres no one answer to this question.

author: magic
author_rank: Super Contributor
timestamp: July 06, 2019, 06:52:45 am
content: Quote from: mrpackethead on July 06, 2019, 01:57:25 amWon't they grow out of the solder blob rather than the PCB footprint?

author: mrpackethead
author_rank: Super Contributor
timestamp: July 06, 2019, 08:52:46 am
content: Quote from: magic on July 06, 2019, 06:52:45 amNo. they occur when you have pure metals ( Zinc, Tin are most common ) that are under compression. Much myth about solder causeing the problem.http://flex.iconnect007.media/index.php/article/54212/get-smart-tin-whiskers-eliminated/54215/?skin=flex

author: mrpackethead
author_rank: Super Contributor
timestamp: July 06, 2019, 09:01:30 am
content: FYI. I prettyu much use Gold ENIG PCB exclusively. the reasons lot for whiskers, its for flatness.

author: magic
author_rank: Super Contributor
timestamp: July 06, 2019, 10:16:36 am
content: Quote from: mrpackethead on July 06, 2019, 08:52:46 amYour link seems to contradict you. It says they nickel-plate not just bare PCBs and components but wholly soldered assemblies to prevent whisker growth.

author: tooki
author_rank: Super Contributor
timestamp: July 06, 2019, 03:41:31 pm
content: Quote from: Monkeh on July 06, 2019, 12:36:58 amI was specifically comparing 60/40 to 63/37. It’s not at all fair to try and discredit my statement by comparing the price of 62/36/2, which is far more expensive.That YOU can’t get 63/37 as easily is not relevant here. The OP is in USA, where it’s widely available. Looking on Digi-Key*, using 0.8mm (0.031-0.032”) RA solder, a lb of Kester is $38.01 for 60/40 vs $39.67 for 63/37. From MG Chemicals, both cost exactly $45.26 for a lb — literally not one cent higher. And with Multicore, for 500g reels, it’s $35.21 for the 63/37 vs $36.01 for 60/40, so actually cheaper for the eutectic.So yeah, when I say the added cost is “insignificant”, that’s an absolutely reasonable way to describe it.*does anyone here know whether Digi-Key will ship leaded solder to Europe? If so, that’s by far the easiest way to get a great selection at low cost.

author: Audioguru
author_rank: Super Contributor
timestamp: July 06, 2019, 03:56:34 pm
content: Doesn't Farnell (Element 14) sell solder in Europe at low cost?EDIT: In Canada there is a store and its staff from India. They sell low cost surplus electronics things that companies don't need then sell to them. I buy American solder there and the tip for my Weller soldering iron. Name brand new ICs are also sold at low cost. I bought new AC adapters and clock radios for only $1.75CAN. In one of the clock radios I replaced a few coupling capacitors with higher values for good bass and connected it to a hifi speaker. It sounds great.

author: tooki
author_rank: Super Contributor
timestamp: July 06, 2019, 04:04:21 pm
content: As an EU-based company (well, until brexit...), they aren’t allowed to sell leaded solder to consumers any more.I don’t have any personal experience with Farnell since they’ve been flip-flopping about selling to consumers in Switzerland. First they could, then they couldn’t, now they can... it’s just not worth the effort to bother, since Digi-Key works so well, and ships here just as quickly at just as low a cost!

author: bd139
author_rank: Super Contributor
timestamp: July 06, 2019, 05:17:59 pm
content: Yes you can't buy it now as an individual. Companies can. I had to buy my last roll of 62/36/2 via my company.I did however pick up ten rolls of 60/40 off ebay:https://www.ebay.co.uk/itm/223496505388(they take offers)

author: magic
author_rank: Super Contributor
timestamp: July 06, 2019, 08:42:04 pm
content: A few months ago I was wondering about Mouser and they allowed me to put it in cart and proceed right up to payment, where I bailed out.I think there is a good chance American suppliers will sell solder to consumers for a while, but nowadays they have some official presence in Europe too so the EU may pressure them to stop at any time.

author: mrpackethead
author_rank: Super Contributor
timestamp: July 06, 2019, 08:49:41 pm
content: Quote from: magic on July 06, 2019, 10:16:36 amwhat i shoudl ahve said. Whiskers occur when you have *Some* pure metals ( Zinc and Tin are most common that are under compression. The main point is using Lead Free Solder in itself does not cause Wisker growth.

author: hunghoang
author_rank: Newbie
timestamp: July 24, 2019, 12:35:00 pm
content: I recommend Weller WLC100 40-Watt Soldering Station.

author: RiRaRi
author_rank: Regular Contributor
timestamp: February 26, 2025, 05:21:32 pm
content: I am looking for good solder for vintage audio equipment from 1970s and 1980s. Want to go with Kester 63/37 as i think that is the best one. But my concern is should i buy Rosin core, RMA, or RA for vintage audio from 70s and 80s. Someone will say it is the same but there is more probability for corrosion or RA and it should be fully cleaned. What do you use?

author: Psi
author_rank: Super Contributor
timestamp: February 28, 2025, 10:10:26 am
content: I like Kester 67/37, RMA, series/flux type 285I have a dual stack solder reel holder with 0.8mm and 0.3mmQuote from: RiRaRi on February 26, 2025, 05:21:32 pmQuoteYou get RA but only have to deal with RMAYou can also choose between 1.1% 2.2% or 3.3% flux content if working with heavily oxidized parts.The main downside is it's a bit pricy. But comparable to other high end solders.Although, looking on digikey it seems to have dropped it price, used to be over NZD$100 for a 500g roll, now it's $70

author: Simmed
author_rank: Frequent Contributor
timestamp: February 28, 2025, 10:32:16 am
content: i heard about eutectic 58Bi/42Sndoes anybody have experience using this ?does anyone use this exclusively as their best pick ?

author: kuwoyuki
author_rank: Newbie
timestamp: March 02, 2025, 10:53:48 am
content: Honestly, there are good Chinese brands like "Mechanic", the HX-T100 63/37 is great. Or "HIROSAKI" (supposedly Japanese but actually Chinese) and the quality is surprisingly decent