Soldering bench?

2" tubing will be quite restrictive. 4" tubing is lots less. I find that the hose sold for clothes driers is around right, combined with several 4" fans in series (Make a box fitting several 4" fans, with around 4" space between them, and a cross of cardboard between the fans for 3" to stop the air spinning, so that they actually increase the pressure. You might consider going to lead-free solder. AIUI, all of the lead will fallout quite close to the soldering station, without ventilation. The flux fumes are just flux fumes.

Why not just use resin-free solder - less fumes. The flux isn't as active as resin, so your boards need to be tinned properly; it doesn't work very well on home-made PCBs with bare copper.

Leon

Hey Dan,

Just a suggestion, as I have not done this, but what about one of the economical stove/range hoods available at any harware/builders supply store? You could easily arrange one as a fume-hood I think. They are fairly light-weight, and could easily have a cardboard or plywood shroud made up to sit on the desk or bench. Get one with an outside venting kit and a variable speed fan. I know Home Depot locally has them on sale from time to time for about 50$.

I'm sure others will advise that newer solders are "lead-free", and that the burnt flux smell is non-toxic, but if all it does is get rid of an annoying odour, why not?!?!

Take care.

Brian Laws>I do light-duty electronics work in my home shop on a fairly regular basis.

You could just get a kitchen range hood (well, make sure that it's a range hood that actually vents outside, not a useless one that blows back into the room). Free if you have a neighbor who's remodelling, and you ask nicely.

2" tubing is too small. 4" is commonly available, including flexible/bendable, as clothes dryer vent. Whether or not you get a kitchen hood, I'd suggest a hood over the bench, as well as your point-suction tubing.

It is Rosin, not resin. Buy a vent hood for a stove and vent it outside.

"Resin is the generic term for all sorts of sticky fluids and gums exuded by plants. Synthetic resins are manufactured in imitation of these and are widely used in the making of plastics. Rosin is a particular natural resin from pine trees; in dried powder or cake form it is used by gymnasts and other athletes to prevent hands and feet from slipping and by musicians on the bows with which they play stringed instruments, to insure firmer contact between bow and strings."

Multicore, who make lots of soldering products, call it "resin" - they ought to know. 8-)

Leon

First off, the major source of lead contamination is not via fumes. Molten lead actually has a fairly low vapor pressure so unless you are drastically overheating the solder connections you are probably safe in this regard. The largest issue by far is the *handling* of solder and soldered joints - and then the hand-to-mouth contamination that happens when you have your cig or cup of coffee, etc. So introduce a hard and fast rule to wash your hands before eating or drinking anything.

As others have mentioned the flux fumes represent some annoyance and indeed health hazard. So you could look in a Newark catalog to see the sorts of setups they sell commercially, or if you want to do it right then a three inch centrifugual blower run off a

1/3 hp or so motor can pull suction on a swing-arm mounted vent hood. You could look in Lab Safety Supply's online catalog to get some idea of what they sell, it's very nice but priced out of sight for the hobbyist. But you could see what they do, and then rig up a similar arm type of system.

Jim

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...

I use a 5-sided open-front cubical box with a single 12V 4" fan in the top back. I run the fan at 9VDC rather than 12 (the lower voltage cuts down on fan noise) and it definitely has enough draft to pull fumes out of the 13x13x13" work area, into a 3" tube to a window. If you don't have a hood or enclosure, you need faster fans or more fans, and fan noise gets to be a problem.

-jiw

If you can't vent to the outside, look in the soldering section of any major electronics catalog. They have bench top fan/filter units to suck up the smoke and pass it through a carbon filter. They're not cheap, but you could buy the replacement filter and make your own fan/filter/enclosure box.

My wife has been doing stained glass for years and she uses a special hand cleaner designed for people working with lead based products. She also uses a small fan equipped with a charcoal filter. All the stuff is available through your local stained glass supplier.

My wife is as careful as she can be but just last week she decided to asked our family doctor to do a lead level blood test just to be on the safe side.

Jimbo

She will probably test out quite clean.

No special hand cleaner is needed, just plain old soap/water works fine. I do a *lot* of soldering on a daily basis at work but am scrupulous about washing up before lunch or coffee break.

Jim

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I think using a computer fan and 2 inch tubing would work for you. If you have double hung windows, you could just put the tubing thru a 2 by 4 that is as long as the window is wide and close the window on it. The 2 inch tubing will be fairly restrictive so someones idea of two fans in series might be a big help. Something like this is unlikely to get 100 % of the fumes, but should get more than half and that is probably enough. An ion generator might help too.

Dan

I'm coming up on the tail end of this discussion, but I still might be able to add something. I've seen production hand soldering areas that were run

16/6 that tested fine for airborne lead so I think there isn't much danger to your house or occupants. Regardless, companies install systems like yours and they typically use something like 4" dryer vent hose. As to the flux smell, what you need there is solder with "no clean" flux. It isn't as active as something like "kester 44", my favorite, but it doesn't smell and it doesn't need cleaning.

[ ... ]

Agreed.

Note that some (including myself), are allergic to the fumes of rosin soldering flux. I have asthma, and this can trigger it.

I can simply stand a Rotron muffin fan on the bench beside my work area, and let it blow the flux fumes away. By the time they circulate back to where I am sitting, they are dilute enough to be no problem -- unless I am using a soldering pot with flux on the top to clean up the surface for dipping. *That* I will now only do outdoors, or in a fume hood (if one is available, as they were at work before I retired).

Good Luck, DoN.

[ ... improvised fume hood from stove vent kit ... ]

Just to the reference of newer solders being lead-free. I don't think that any of them have as low a melting point, and as good a eutectic mix available -- both good things for electrical connections, especially on printed-circuit boards some of which are particularly vulnerable to heat damage. I know that I am stocked up with what may be a lifetime supply of various gauges of lead/tin solder in preference to the later substitutes.

The toxicity should not be a problem if you don't smoke while doing the work, and wash your hands after you are complete -- *before* eating anything.

Enjoy, DoN.

You are overly paranoid about lead fumes. Normal electronic soldering doesn't reach temperatures where there is a significant lead vapor pressure. However, the flux fumes are annoying.

I just use a box fan to keep the fumes out of my eyes.

Gary

Me too. Instead of taking the fumes away, I took the different tack of using several fans in the attic to blow air down a tube, for breathing air. This blows air into a facemask, and keeps both nose and eyes in clean air.

Agree with the first statement, said so myself a while ago.

But the second... I've heard that voiced here in the thread several times already.

Am I the *only* one here who finds rosin flux aroma to be pleasant and relaxing? My wife btw says it reminds her of catholic church!

Jim

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No, you aren't! :)

Tim

-- "That's for the courts to decide." - Homer Simpson Website @