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Can a solder gun get too hot?


jwc

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I'm a battle hardened veteran: When you first fire up the hot melt gun, the first couple of pulls on the trigger sometimes shoots out some glue that is a little discolored. I got in the habit of pulling the trigger a couple of times over some paper towels before I use the gun on a board. After doing this once, I set the gun down while I gathered some parts up. There was an inductor on the other side of the bench, and as I casually turned and leaned over to get it -- I thought it would be a good idea to put my hand into the hotmelt I had just squirted into the paper towel. The bad thing about hotmelt is that when you lift your hand out of it, it happily follows along. The stuff is basically liquid plastic, and as I was peeling it off my hand the skin came right off with it. No solder burn I've incurred has even come close to that one.

I have a story about removing a bias resistor out of a tube amp too -- wanna hear it.:)

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Well Dean...let's be glad you didn't get hot glue on your penis. Once cooled....hhmm...not good. Trust me.

That link..Dean...Is that what you use or is that what you burned yourself with?

Well, I discovered something tonight. That resistor didn't get too hot. I realized what a dumb thing I did. I had used some electrical tape to momentarily hold the resistor in place. The sticky stuff was from the tape....not the resistor. Stupid. I am somewhat pleased with the solder gun I have for the moment.

Anyhow, I did the techique with the alligator clamps grounded to some of those left over 2.5 mHy steel bridge inductors. Worked great.

jc

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uh, which end of the soldering iron should I hold?

It keeps sticking to my hand![:$]

lol

I'm such a klutz when it comes to doing anything...I've got so many

scars from burning myself with the iron. But it's not so much from

holding the wrong end, but rather bumping into the iron.

I've got a nice one on my arm where it just melted my skin like butter

- stuck to my arm when I tried to pull away and then burned my hand

when I tried to catch it before hitting the floor and then burned my

other hand trying to catch it again. And then finally put my foot

underneathe which also got burned until my dad reached over and picked

up the iron with the cord. I guess that's what I get for soldering at

the kitchen table over a hardwood floor, lol.

Anyways, you risk more damage from too little heat than too much heat.

The better you get at soldering the less time you need to apply heat to

achieve a good connection. Eventually you want to get to the point

where you just touch everything together, apply the heat for a split

second and pull it away. This of course requires a lot of heat so that

everything gets hot enough to prevent a cold solder. The guy that

taught me how to solder was soldering PCB boards all day long with a

250W iron...(basically building the old 486 motherboards - so lots of

fragile parts). When you have too little heat you end up applying the

heat for longer which gives enough time for the senstive stuff up

stream to heat up.

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I have never found a use for a solder gun. The results on a junction always looks like a bird dropping.

There are a bunch of 25-40W irons that do great electronic work. I have several of each. I really like the ones with silver tips. They are getting hard to find.

As to heat sinks, I have a box of alligator clips of various sizes. They are fine for most work. I also have some hemostats (surgical clamps) for special circumstances. They latch, so you free your hands.

In older work, never overlook the usefulness of soldering paste (NoKoRode) and others. You don't need much! Touch a q-tip to the paste and then to the junction. If you can see it, you used too much.

For larger work, I have several sizes of propane torches. Touch the junction with paste, heat the joint with the torch. Remover the flame from the joint. Flow the solder on. You can "brush" the joint with the flame to make it pretty if it isn't.

You can buy a "soldering station" for several hundred dollars or several good irons for $10-12 each and expect very much the same results. It all depends on technique. Any old-time bench tech can teach you to solder in 15 minutes. It is like anything else. The art comes with practice.

Here endeth the evening lesson. TBTG.

DR BILL

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I am with Dr. Bill on this. Thermostatically controlled soldering stations are sweet. But the most useful thing for me is good 40 W iron. The right tip for the job makes a big difference. And when I need more heat propane is the way to go.

I actually have some real heat sinks I picked up years ago. They clip on leads, etc, have a lot of mass, and work much better than aligator clips.

FWIW more components have probably been damaged by someone using too small an iron than too big an iron. With a small iron, the junction takes forever to get up to the temperature necessary to melt the solder while the heat drains away to other areas and lift traces, bubbles insulation, and does other damage.

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The 1/8 screwdriver tip that comes with the Weller is a good one to use for most small electronics work. One of those will last at least through building a few hundred crossovers.

While we are talking about soldering equipment, I might mention that I like to have five different ones around.

1- A temperature controlled one like the Weller station for most electronics work.

2- A dual heat gun for working on automobile wiring, or a quick job on a large wire.

3- A 100 watt iron in case I have to work on an AL crossover or any other poorly constructed stuff with too many wires connected to one junction.

4- A propane torch. In case I don't want to wait for the 100 watt iron to warm up or I am changing the connector on an electric fork lift or its charger.

5- A very cheap one to carry in my truck for loaning to Dean.

Bob Crites

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One thing I forgot in my wanderings, and I haven't seen anyone here address it. It is absolutely necessary to clean the tip of the iron before each use and frequently thereafter.

Use a piece of old terrycloth cut into a four inch swab. Plug in the iron, and when it gets just hot enough to melt solder, hold the tip over the trash box and flick the old solder off. Tin the iron and get to work. Any time the tip becomes dull gray (as opposed to silver) repeat the cleaning. This is particularly important if several minutes have passed since the last junction was soldered.

Someone else mentioned this but I'll improve the answer. In choosing which wattage iron to use, err toward the higher wattage. It will make the junction quicker and there is less time for the heat to travel. My dad always quinched the solder joint with spit! He would wet his finger and then touch the newly soldered junction. I never imitated him. He also would check for live circuits by touching the wires. I never imitated him! I DO blow on the junction and I also use the aforementioned heat sinks if I am dealing with sensitive parts.

Solder slowly dissolves copper. Your tip will erode to a jagged mess. Reshape it with a file. Reheat and tin the bare copper. Never file a silver tip.

DRBILL

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Just my opinion for what it's worth, but you really shouldn't do anything to a new joint, except to let it cool to room temperature on its own. Don't move anything, don't blow on it, whatever. I do a few joints and walk away!

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Just my opinion for what it's worth, but you really shouldn't do anything to a new joint, except to let it cool to room temperature on its own. Don't move anything, don't blow on it, whatever. I do a few joints and walk away!

I used to do that too! That was college, though.....[;)]

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That's that stuff you brought to me, right Doc?

This is fantastic, cleans and retins in one easy dunk in it's paste-like compound. Very cool stuff. Just double-stick it to your iron holder and you're good to go. Looks like it would last a long time too.

M

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