View Full Version : I want to teach my son how to solder

February 14th, 2013, 08:12 AM
I have heard that leaded solder is restricted in Europe.

I have some old solder which contains lead; I would prefer not to use this with my son, I am consider using kester lead free solder however I am not sure if it will work with my old 15 watt solder iron. I have heard lead free solder needs higher temperature to melt. Does anyone know if I need a hotter solder iron or will I be fine with my 15 watt solder iron?

What other soldering accessories would you recommend, would a flux pen be useful.

Also regarding removing solder, is a de-solder pump better than a de-solder braid.

Thank you in advance

February 14th, 2013, 09:52 AM
A 15 Watt iron will be fine if you're only doing small work. If you're soldering bigger wire (18 AWG and up) you'll want a bigger iron with lead-free. Regular plug-in irons are "constant output," meaning they always burn their rated wattage in electricity -- if you don't use the heat up with soldering, it will tend to "build up" a bit higher than the working temperature. Wouldn't worry about flux as long as you're using flux core solder.

Solder braid and desoldering pumps are both good, but for different kinds of desoldering. I use both regularly.

February 14th, 2013, 11:58 AM
I wouldn't worry about leaded solder. It still produces a more malable joint and if you are repairing equipment built with leaded solder then you must use matching , i.e. leaded solder..

February 14th, 2013, 03:01 PM
Yeah, we all grew up soldering with it, and look how we turned out! Oh, wait...

In all seriousness, studies show that high levels of lead are only serious to young children. If he's old enough to wield a soldering iron, it's probably not a big risk to him unless he's doing tons of it or puts solder in his mouth. Just wash hands before eating.

February 14th, 2013, 03:49 PM
Show your son where the ice cubes are kept and what to do with them in the eventuality that he comes into direct contact with the hot end of the iron. I still have a vivid recollection of picking up a 100W American Beauty iron by the hot end... :)

February 23rd, 2013, 12:29 AM

I have heard that leaded solder is restricted in Europe.

I have some old solder which contains lead; I would prefer not to use this with my son, I am consider using kester lead free solder

Actually, no, the EU likes to regulate a lot of things but leaded solder is the norm for hobbyists and you can buy it anywhere. Lead-free soldering is an environmental thing regulating mass-production electronics, they don't want lead to end up in landfills.

But for the hobbyist, leaded is for sale eveywhere. When soldering, it's not the lead that poses a health risk but the fumes from the flux/resin core. I googled quite extensively on this topic (for very much the same reasons, time to get my son interested...) and findings are unambiguous:
- avoid the poisonous fumes from flux/resin by keeping the room well ventilated
- afterwards, it's nice to wash your hands if you're concerned about lead contamination - but it's not in the fumes.



Steve Johnson
April 16th, 2013, 02:12 PM
AS stated above leaded solder is OK to work with. The fumes are from the flux. You can avoid flux fumes by placing a small fan on the bench near your work. It will draw the fumes away from you. They make commercial solder fume extractors but for years I used a 12 volt DC fan and housing from an old PC power supply. Here's an example (bottom of page): www.stevenjohnson.com/soldering/tools.htm (http://www.stevenjohnson.com/soldering/tools.htm)

Here are some links to on line videos to help with training.
Some of them are vintage but the rules still apply: www.stevenjohnson.com/soldering/instruction.htm (http://www.stevenjohnson.com/soldering/instruction.htm)

If your worried about him using lead based solder just have him keep his fingers away from his eyes and mouth and have him wash his hands afterward.
We all survived so I wouldn't worry about anything but the flux fumes.

April 16th, 2013, 02:46 PM
Isn't most leaded solder flux (for electronics, not for plumbing) just rosin? In the past, I've even made my own liquid soldering flux from 'cello bow rosin, dissolving chips of it in alcohol. Exactly what makes the fumes toxic--after all, it's just tree sap. And the amount contained in a few inches of AWG 16-18 electronics solder is miniscule.

Now, acid-soldering flux I can believe. That stuff is nasty to get up your nose.

April 16th, 2013, 05:33 PM
AFAIK, rosin flux fumes are not toxic, they are simply an irritant that can cause problems for folks with asthma or continuous prolonged inhalation. Other flux blends may be a different story, such as some of the "no clean" fluxes. I have some no-clean flux that I use when I do lead-free SMD work, and the stuff is nasty to smell compared to rosin. Rosin works well with lead-free, too, but the specific no-clean flux that I use with lead-free stuff works a little better.

I don't always bother with ventilation, and when I don't I just make sure the flux fumes aren't coming up into my face. When I do, I have a pair of 8000 rpm 80mm fans out of a server which are rated for full speed at 12v. I connect these to my variable 1A leg of my bench power supply, and set the speed where it works best, usually drawing air away from the work. They're zip tied together in a rectangular brick that works rather well on the long end, or can be stood up stable on the narrow end provided you don't give it too much thrust. This combo will push itself across the bench, if it's on a low-friction surface. Even an old beat up fan that doesn't work right in a PC any more will work fine, just pop the sticker off the bearing cover and spritz a little WD40 or put some light oil in it, and even a worn out sleeve bearing will spin full blast for a long while.

Echoing the sentiment of the others, lead solder isn't a problem for hobby use, you're not signing any RoHS compliance documents for what you're building. Lead-free solder does take a touch more heat to flow, and when it does flow it's not as smooth. You'll never get a glassy-smooth solder joint with lead-free solder, and it may "slump" more than lead solder.

Even still, you're talking about something that is typically 60% tin and 40% lead (or even less lead) that is replaced by an alloy of about 96% tin and 4% copper (or less). Most of what you're working with is tin anyhow.

As for desoldering, wick(braid) and pumps work very well, but as someone else pointed out, they're used in different ways. There are even different types of pumps. Some are a simple rubber bulb with a plastic tip, some are spring-driven piston pump "one-shots", some are a combination of the bulb and a soldering iron, and then there are full-blown vacuum desoldering stations ($$). If you're on a budget, the bulb and some wick will do you fine. If you can spend a bit more, the cheap one-shot pumps and the cheaper bulb-on-an-iron pumps are usually within the same price range. For beginners who can afford it, I typically recommend the bulb-iron device.

This picture I just found on the web shows the difference between a one-shot pump, a bulb-iron desolderer, and a roll of wick:

The great thing about the bulb-iron is that it's about as close as you can come to a vacuum desoldering station without a vacuum pump. You use the device itself (with the bulb squeezed) to flow the joint until it wiggles, and the release the bulb. Also, if you come across a small, cheap surplus vacuum pump, it can be converted. :) The bulb irons usually go for between $10 and $100 depending on how much you care about a brand name.

Other than that, I'd say buy some cheap elenco kits (especially their learn to solder kits) and go to town. The documentation is brilliantly written (practically lifted from 60's/70's heathkit docs, by the looks of them) and will tell you how to do it right, and how to tell if you've done it right.

Hope this helps!

April 16th, 2013, 09:15 PM
I can heartily recommend the soldapullt-with-iron setup shown below:


eBay item 140918912732. The great part is that you can use it with one hand.

Ole Juul
April 16th, 2013, 10:42 PM
I'm with Chuck. The "fumes" are just rosin. I find it personally delightful and would argue that it's good for you. :)