How to Tin Even the Grungiest Soldering Iron.

About: Working my dream job in the Telecom industry, so chances are, i'll never have time to respond to comments or messages, nothing personal.

Let's say you've been a bad maker and let your soldering iron tip get to the point where it's hopeless trying to tin it. Now you can rejuvenate that crusty old tip using a remarkable new technique that's been around for centuries.

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Step 1: What You Need Is...

Some Sal Ammoniac, now I know that that sounds like the name of a Borscht Belt comedian , but it's actually Ammonium Chloride. And it's sold in blocks at places that sell stained glass supplies and occasionally Ace.

Step 2: Here's What You Do

Heat up the iron, nice and hot, hotter, your getting there, no, hotter, okay Now start rubbing the tip on the the block of Sal Ammoniac, gently now, back and forth, back and forth, round and round and round again. Bored? Too bad. Actually it only takes about 20 seconds. Now the iron will start decomposing the Sal and giving off clouds of HCl and ammonia smoke, try not to breathe it, it's probably not good for you. At this point, you have made a little hole in the block, and you want to feed in a little solder, keep rubbing it around and the tip will be re-tinned. TA-DA!

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    30 Discussions


    11 years ago on Introduction

    HCl IS EXTREEMLY POISONOUS, I cant spell, but it is bad... even if inhaled it will kill you... hydrocloric acid... good instructable though.

    7 replies

    Reply 3 years ago

    It's not hydrochloric acid... but still dangerous


    Reply 11 years ago on Introduction

    Hydrochloric acid is NOT poisonous. Your stomach is full of it! You wouldn't want to breathe it in though, acid in the lungs is a bad idea. But it isn't poisonous!


    Reply 4 years ago on Introduction

    HCL is a gas, and is most definitely poisonous. HCL alone is not hydrochloric acid. Hydrocholic acid is the aqueous solution of HCL (or if you prefer, HCL dissolved in water).

    When HCL is inhaled it dissolves in the moisture on the mucosal membranes and anywhere else there is moisture, whereupon the moisture becomes hydrochloric acid. Much of the damage occurs before even reaching the lungs where, of course, it does even more damage.

    Poisons do NOT have to be ingested. If you were right then Sarin gas is not poisonous, nor is snake venom, nor any of a myriad of other poisons just because they're not eaten.


    Reply 7 years ago on Introduction

    I bought a new soldering iron, chisel-tip, 40 watt. I have gone through over a foot of non-lead resin-core solder, and it won't tin at all: the solder just balls up and falls off. I wiped it with a wet sponge, tried paper & scraping it on wood; I even lightlly used sand paper ... nothing. I feel like vomitting on it to get it coated with HCl. Also, I tried soldering with it untinned, & the solder won't melt into the wire : the wire and the solder got too hot to hold, but still nothing.


    Reply 11 years ago on Introduction

    it is used for cleaning and fluxing solder joints... if it was a silver kind of colour then it would be used for SMTs Unless it days rosin on the tin, I highly do not recommend it for electronic soldering because it is probably solder acid used for plumbing and will eat away at circuit boards.


    3 years ago

    Use paste to clean before and after every soldering session, that way you don't have to deal with this


    3 years ago

    Yep. This works wonders, but do it in a well ventilated area, preferably with a fan to dissipate the smoke. HCL is toxic to your mucous membranes...but probably will not kill you in small amounts.


    3 years ago

    It can be easily done with soldering paste and solder.

    Just clean old solder while the iron is hot or file it cold if too dirty.

    Then while it is cold, dip it in paste and turn it on. Keep deeping it in the paste while heating so that it doesn't become in contact to oxygen. Don't let it run dry. Keep trying to melt the solder on the paste wet tip as you must tin it before it becomes too hot that it burns out the paste. I've successfully retinned several very bad irons like this. The trick is: never allow the hot tip to get dry and in contact with air. Oxides will form and prevent solder to stick to the tip.


    8 years ago on Introduction

    The reason why sanding / grinding is not a long term strategy is that soldering iron tips are made of copper, but are iron plated (Actually plated with several metals).

    If you eventually grind or sand through the plating, the tip degenerates very quickly. Looking at the tip in the picture makes me wonder whether this has already occurred.

    Radio Shack and others sell little tins of "tip tinner" that is used in about the same technique as the instructable. Smells nasty while using. Several instructions (in various readings) caution users to wipe the tip off throughly with water / sponge, instead of the growingly popular brass "scrubbies".

    1 reply

    Old tiymer way is to use an tin can bottom heat the iron up then rub it around the bottom of the can while applying solder to the iron

    Instead of going out an buying a new tip, could I sharpen the tip with a sander or a dremel tool? Leaving soldering irons on overnight kind of tends to make the tip fall off.


    9 years ago on Introduction

    sanding worked for me!  thanks. Rock on! I thought it was a problem with me but that worked!


    10 years ago on Introduction

    I also sand the tips of my irons, quick, easy and leaves no nasty chemical smells in the air... :P


    10 years ago on Step 2

    Good job. I didn't know I could do that. I already have the ammoniac. I'll try it.