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Very frustrated!! Have gotten into electronics recently and watched many videos about soldering and proper technique. I started out with the iron from this kit:

https://www.amazon.ca/gp/product/B0009Z3JJA/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

It's not variable temperature, just plug in and use. So I waited for it to heat up, tinned the tip with my solder and used as I had seen in all the videos I watched, cleaning it on a wet sponge after every few solders. I thought maybe I had left the iron on for too long as the tip became blackened and the solder wouldn't liquefy when making contact with the iron tip. So I clean it off on the wet sponge a bunch and it starts looking better, but I still can't tin it. So I follow the instructions in this video:

https://www.youtube.com/watch?v=2VlvjdaMARM

I purchase this flux: https://www.amazon.ca/gp/product/B01EYJJEEK/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Get my iron heated and sink it into the flux, but the solder still won't stick to the tip, it just kind of balls up if i bring it to the edge of the coated part of the iron (the edge opposite of the tip). I think ok maybe it got burned out or something because I left it on too long, also it was part of a $20 kit so maybe it was just a piece of crap.

So I buy this guy here:

https://www.amazon.ca/Elenco-SL-75-Soldering-Station/dp/B002KIYSHQ

Variable heating, I check the manual it says to heat it just beyond the 4th notch to about 700 degrees for lead-free solder. I heat it right where it says to and wait, it tins and everything is fine and dandy. I start using it, this time cleaning between every solder because I'm trying to be extra good to not mess it up, but after 28 solders it stops working

I can't tin it, even while trying after dipping it in the flux. The solder doesn't liquefy at all.

The station came with two tips, the left one is the one I used that no longer works, on the right is what it looked like before: https://i.stack.imgur.com/aVXc7.png

This is the tip of the first iron I used that stopped working: https://i.stack.imgur.com/lsXhk.png https://i.stack.imgur.com/oE7QG.png

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    \$\begingroup\$ What solder are you using? Something is getting on the iron that oxidizes and is introducing impurities. The only place that comes from is what you're adding to it. \$\endgroup\$
    – spuck
    Nov 22, 2019 at 18:30
  • \$\begingroup\$ Be sure to clean the tip when you put the iron down, not when you pick it up. Cleaning (on a damp sponge) cools the tip just when you need a good temp. \$\endgroup\$
    – John Canon
    Nov 23, 2019 at 6:49
  • \$\begingroup\$ @JohnCanon i thought i was supposed to clean it on the sponge after every solder \$\endgroup\$ Nov 27, 2019 at 3:45
  • \$\begingroup\$ @spuck lead-free but it was highly rated on amazon \$\endgroup\$ Nov 27, 2019 at 3:45
  • \$\begingroup\$ Yes, clean it on the sponge after you make the solder joint. Then the heat has a chance to come back up to normal in time for the next solder joint. Here's a quick tip: for heat sensitive devices, use heat sink tweezers. If you need to solder multiple terminals on a device, first solder one terminal and let it cool for a few minutes between each of the next solder joints. \$\endgroup\$
    – John Canon
    Nov 29, 2019 at 2:26

3 Answers 3

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The soldering iron you bought is provably low quality. A high quality soldering station I would recommend in the same price margin as your previous would be the 937D+, also get solder with flux in it.

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  • \$\begingroup\$ thanks for the feedback, but could it really be so low quality that it craps out after less than 30 solders? the reviews on it dont seem to be THAT bad, most people in reviews say the tips were lasting them a few months \$\endgroup\$ Nov 22, 2019 at 3:25
  • \$\begingroup\$ @robertchen they werent using lead free solder \$\endgroup\$
    – DKNguyen
    Nov 22, 2019 at 3:38
  • \$\begingroup\$ interesting, i didnt think it would be THAT much worse, i only had the damn thing on for like 20 minutes. if i wear a face mask is the leaded solder perfectly healthy? or i saw some soldering irons advertised for use with lead-free solder specifically, should i be using one of those? also what of the irons they use in schools, those are all terrible and use lead free and seem to hold up ok. I appreciate the response btw Im just trying to pinpoint that its not an immediate problem with my own technique since im worried to purchase and ruin a third iron :( \$\endgroup\$ Nov 22, 2019 at 3:43
  • \$\begingroup\$ @robertchen It is that bad. Now you know. The flux for lead free solder is worse for you. The leaded solder itself is worse for you. Flux fumes are particulates so a P100 mask wil do the job.Carbon filters are pointless and have a shelf life. Wash your hands after. You do not need a specific lead free iron. You just need a good iron. They do not use lead free in schools from what I have seen \$\endgroup\$
    – DKNguyen
    Nov 22, 2019 at 3:45
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Cheap irons dont work well with lead free. It is taxing even on a $1k temperature controlled soldering station if you are using the wrong tip size. Not only are your irons not getting hot enough, they are not maintaining temperature and you are using tips that are too small. Lead free does not let you get away with things like that. I have a $1200 station and still use nothing smaller than a 2.4mm chisel tip (conical tips suck because they do not make enough contact) for thru hole with lead free. Is it twice as big as the joint? Yes but I can still squeeze it in and it maintains temperature.

Also lead free solder dissolves the iron in cheap soldering iron tips really fast. I saw a new one get eaten away in about 3 months of soldeiing a few hours every week. It had 4mm or 5mm just disappear. This was a BIG 6mm wide chisel tip.

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  • \$\begingroup\$ appreciate the reply, sorry if this is super beginner stuff but why is the bigger tip better with lead-free solder? also in my case i wore through the tip in like 20 minutes :( \$\endgroup\$ Nov 22, 2019 at 3:45
  • \$\begingroup\$ @robertchen two objects touch and the hot object gets cooler and the cold object gets warmer. the power behind the tip can try to maintain temperature but it can only do so much. the large mass acts as a heat reservoir. and the longer you hold them together the more they reach the set temperature, which has to be set extra hot with a small tip so the large initial temperature drop does not make it fall below melting. infinite tip size lets you set it at exactly melting temperature because there is no temp drop and no chance of overheating. large tip gets closer to this than small tips \$\endgroup\$
    – DKNguyen
    Nov 22, 2019 at 3:49
  • \$\begingroup\$ ahh makes a lot of sense, thanks a ton. given all this, do you still think it would make sense for my tip to have burned out so quickly? also is it possible to tell from the images if the cause of the tips demise was due to being overheated and oxidized or eaten away by the solder? thanks again for all the help \$\endgroup\$ Nov 22, 2019 at 4:06
  • \$\begingroup\$ @robertchen Honestly, the tips are probably fine. It's just that they aren't getting hot enough to melt the lead-free solder for both soldering and tinning. They were already borderline working with lead-free solder to begin with so just a little insulative crud is enough to break the camel's back \$\endgroup\$
    – DKNguyen
    Nov 22, 2019 at 4:32
  • \$\begingroup\$ More likely the iron is getting too hot, not insufficiently hot. Lead free solders tend to expose this issue by oxidizing more readily; lead makes a solder fairly tolerant of abusive treatment. \$\endgroup\$ Aug 29, 2020 at 0:29
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I'm probably being contrary to what you have been reading, but I think that both of the soldering irons that you have purchased are of adequate quality for your use. Instead, I think that you may have two problems: iron temperature is far too high and your choice of solder.

I'm in Canada and we don't have the RoHS restrictions that Europe has. That's good - most of our clients are Industrial and they prefer that we use lead-based solder if at all possible.

Let's go back to the first iron that you purchased. Obtain a brass "brillo" pad and gently clean the tip while it is hot. Amazon has many but the least expensive appears to be: Stanz (TM) Soldering Iron Tip Cleaner with Brass Wire Sponge, No Water Needed. Be sure the wire pad is brass and not steel. There is a much less expensive version but the description says "steel".

Now try tinning the tip with lead-based solder. My favorite solder is Kester 63/37 with type 44 Rosin flux. You can purchase a small pack for not much money just to try it.

You may also want to invest in a decent flux. I use Amtech NC-559 which is also available from Amazon. I've purchased this from several sellers but the best bang for the buck appears to be this: Souked 100g AMTECH NC-559-ASM No Clean Lead Clean Solder Flux Solder Paste Can $18.99

That jar of flux will last you years and years!

Get some copper wire and practice soldering wires together. Old CAT-5 Ethernet cable is good and available for free much of the time. Strip the insulation from the conductors, twist pairs of wires together into a pigtail configuration, solder.

It will take time and patience to get good at this. Graduate to soldering components on circuit boards after you have mastered soldering wires together.

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  • \$\begingroup\$ Some of the thermal-equilibrium irons on the market today are truly garbage; to accomplish a repair with one my brother in law was given, I ended up having to unplug it and use it while it cooled down. \$\endgroup\$ Aug 29, 2020 at 0:28
  • \$\begingroup\$ My experience with such ions dates back to when I was a teenager. Weller W40 - no temperature control but worked extremely well. Perhaps I should not extrapolate that experience with modern offerings. \$\endgroup\$ Aug 29, 2020 at 1:38

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