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I've read in numerous places that an ordinary wet dish sponge can be used for cleaning the solder iron tip. I've taken a photo of what the sponge looked like after I cleaned by solder iron tip and shown it below.

The tip burns the sponge, small amount of smoke comes out and tiny black ashes can be seen on the sponge. Is this normal, or am I using the wrong sponge/wrongly?

I'm sure nobody cares about the sponge, I just want to keep my solder iron tip clean properly without damaging it.

Picture of the sponge

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  • \$\begingroup\$ What is the "right" kind of sponge? Not helpful at all. As for the comment on the question being off-topic, search for "sponge" on this site and see how many questions there are. electronics.stackexchange.com/search?q=sponge Gee, some of you have nothing else to do than vote questions. It has everything to do with people working with electronic engineering, there is no Q&A site dedicated specifically to solder cleaning sponges, or soldering, so enough with this approach already. I know getting the privillege to vote makes you feel important, but you haven't been voted as president... \$\endgroup\$ – Leo Ervin Oct 31 '15 at 20:34
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    \$\begingroup\$ I don't think this off topic at all. Soldering is a key part of electronics and getting it done correctly and safely is just as important as getting a circuit design right. While this isn't about design per-say, there are a lot of questions here that aren't but which are still on topic. \$\endgroup\$ – Tom Carpenter Nov 1 '15 at 0:09
  • \$\begingroup\$ Yeah, this is definitely on-topic. \$\endgroup\$ – Adam Haun Nov 3 '15 at 16:11
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Basically what you have there is a standard household cleaning sponge. These are made from either Polyurethane or Polyester (most likely the latter). Neither of these materials hold water very well because of their structure and material. This means the material will not be cooled by the water and so will be exposed to the high temperatures of the soldering iron tip. They are not designed to withstand the heat of soldering - for example polyester sponges will melt at 250*C.

Sponges used for soldering are made from compressed cellulose. This is much denser and critically will hold water and stay damp (you want the sponge damp, not wet!). If it is kept damp the sponge will withstand the temperature of soldering because the water inside it cannot be heated above boiling point - it turns to steam if you try. Now if you were to hold the soldering iron on it for an extended period of time, the water would eventually evaporate away and the sponge would melt, but you don't normally hold it there long enough to do that.

Googling "Compressed Cellulose Sponge" or "Soldering Sponge" will find you many results of where to buy the correct sponges.

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  • \$\begingroup\$ I know this is going to sound way unprofessional, but while getting an itch to solder while on an unforseen shortage of an actual soldering sponge, I got by with what's called in French a Lavette en cellulose très absorbante, which I picked up from a [French] supermarket. I don't even remember seeing something like that in the US, because everyone there has dishwashers... \$\endgroup\$ – Fizz Oct 31 '15 at 21:01
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    \$\begingroup\$ I can't speak for the U.S., but in Canada you can find cellulose sponges in almost every dollar store, and I've had much success using them in place of a "proper" soldering sponge. And they're six full-size sponges for a few dollars rather than a single tiny sponge for the same price. \$\endgroup\$ – Ignacio Vazquez-Abrams Nov 1 '15 at 4:06
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    \$\begingroup\$ When a cellulose sponge isn't available, a paper towel from the washroom folded over a few times and dampened can be a temporary substitute. \$\endgroup\$ – Chris Stratton Nov 1 '15 at 21:20
  • \$\begingroup\$ How can you tell a sponge is a cellulose sponge if there's nothing on the label? Density and hardness? \$\endgroup\$ – Leo Ervin Nov 3 '15 at 0:13
  • \$\begingroup\$ @LeoErvin it should be fairly obvious from the look and feel. It won't look like or feel like plastic, more like card/wood when dry. If it feels soft when dry, it's not what you want (there are some car sponges out there that look similar but are not the right thing). \$\endgroup\$ – Tom Carpenter Nov 3 '15 at 3:21
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First, I would make sure you have a synthetic sponge and not a organic one. Those are more durable to stand up to the heat, when your wiping off your soldering tip. Organic sponges seem to burn and smell when they are used for soldering. They do make sponges that are specifically for soldering. Those are probably a good synthetic material that are durable enough to handle the heat from the tip. They also come with or without holes, which can help get the tip clean faster.

Also if you are using lead-free solder, using a wet sponge will crack the plating on the tip, causing it to oxidize faster, and shorten the life of the tip. In this case, I would recommend using a wire sponge. You can use them dry and are becoming more common since they last longer.

If you aren't sure what kind of sponge you have or what kind of solder you are using, I would recommend using either a dry metal sponge or one specifically designed for soldering. This way it saves you money on tips.

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