Ventilation

[Marty]

Specifically, ventilation for stained glass soldering. I know there are forums (fora?) for SG but I want to know what the denizens left here have to say.
When I've messed with SG in the past I worked in front of a serious lab-style extraction hood but I will need to provide ventilation for 6-8 students at a table to deal with fumes from flux and solder. (Yes I know that there are "healthy" alternatives but they don't work as well as the good old toxic stuff.)
I'm also trying to avoid unsightly ductwork (sounds like the "heartbreak of psoriasis").
Does anyone have information or experience with the desktop filtered extractors? I've seen them for about $60-$90 each- do they work for stained glass or are they mostly for electronics soldering?

Greg Rawls- you still there?

[Greg Rawls]

Hey Marty - been a while! The main inhalation issue with stained glass is possible lead fume exposure. I've not looked at this for a long time. As I recall, there is not enough heat to create actual lead fume as the smoke created during soldering is from the flux and that is an acid gas. Most lead is 60% tin/40% lead which reduces exposure potential. Actual exposure depends on how much you are soldering. In my opinion, if you are doing it less than 1 hour/day, I would have some general room exhaust ventilation (aka - a fan in the window near your work). If you are using a desktop unit, I would be concerned with where the fumes go. Are they being exhausted out of the room or is there a filter? If there is a filter, it should be HEPA/P100. Fumes are easily captured so you don't need a really high capture velocity. Don't forget issues with possible ingestion. Make sure no eating or drinking at the table and that everyone washes up after work.

[Greg Rawls]

Or you could put everyone in P95 respirators. Easier to wear and cheaper than P100 and almost as efficient.

[Marty]

Greg- Good to hear from you. I think the station fans have charcoal filters in them.
I always thought that the lead fumes were the least of the problem. Soldering is about 700F, way below vapor points. However some of the lead casting groups have discussed this and the oxide issue was brought up: some lead and tin oxides can vaporize from 800F and up.
My main concern is fumes from the flux- zinc chloride is a pulmonary irritant (at best).
As to masks- a passive system will work much better in terms of compliance.

[AndyT]

Hey Marty - been a while! The main inhalation issue with stained glass is possible lead fume exposure. I've not looked at this for a long time. As I recall, there is not enough heat to create actual lead fume as the smoke created during soldering is from the flux and that is an acid gas. Most lead is 60% tin/40% lead which reduces exposure potential. Actual exposure depends on how much you are soldering. In my opinion, if you are doing it less than 1 hour/day, I would have some general room exhaust ventilation (aka - a fan in the window near your work). If you are using a desktop unit, I would be concerned with where the fumes go. Are they being exhausted out of the room or is there a filter? If there is a filter, it should be HEPA/P100. Fumes are easily captured so you don't need a really high capture velocity. Don't forget issues with possible ingestion. Make sure no eating or drinking at the table and that everyone washes up after work.

No lead fumes are generated during soldering. The only fumes are from the flux. Wear a mask, have a window open and a fan. there are fume extractors out there also.


The boiling point of lead is 1749C/3182F

[Marty]

That's what I was asking- any experience with the desk top (ductless) extractors?

[Greg Rawls]

Greg- Good to hear from you. I think the station fans have charcoal filters in them.
I always thought that the lead fumes were the least of the problem. Soldering is about 700F, way below vapor points. However some of the lead casting groups have discussed this and the oxide issue was brought up: some lead and tin oxides can vaporize from 800F and up.
My main concern is fumes from the flux- zinc chloride is a pulmonary irritant (at best).
As to masks- a passive system will work much better in terms of compliance.

Charcoal is good for organics and acid gas (Zinc chloride). Fumes need a HEPA.

[Buttercup]

Interesting topic. Working alone I position a fan to blow fumes away from me, gently, so as not to cool the soldering iron. With a group that wouldn't work as someone(s) would always be in the firing line.

I've been thinking about a range hood exhaust fan dangling over the layout table. That way the fumes would go straight up, not laterally. In my situation it would be easy to vent but that may be an issue for your situation. They are inexpensive on eBay or Gumtree.

(SORRY! Didn't mean to highjack your thread, Marty).

[Greg Rawls]

That's what I was asking- any experience with the desk top (ductless) extractors?

Nope. Always worked in industry with really BIG vent systems.

[Marty]

Interesting topic. Working alone I position a fan to blow fumes away from me, gently, so as not to cool the soldering iron. With a group that wouldn't work as someone(s) would always be in the firing line.

I've been thinking about a range hood exhaust fan dangling over the layout table. That way the fumes would go straight up, not laterally. In my situation it would be easy to vent but that may be an issue for your situation. They are inexpensive on eBay or Gumtree.

(SORRY! Didn't mean to highjack your thread, Marty).

The range hood works- I've done it- but you'll need to enclose the back and sides so air flows from behind you and across the work away from your face. Cardboard or corrugated plastic (like lawn signs) and duck tape works for that. I've never tried setting the hood up vertically...
But you'd still need to vent- recirculating vent hoods only filter for particulates like oil droplets, not fumes. I'm trying to avoid vents if I can.

You don't have to worry about cooling the iron with moving air unless you've got the fan set on gale-force.

[AndyT]

That's what I was asking- any experience with the desk top (ductless) extractors?

I think the Hakko is probably the best for a small space. I've heard some folks use a stove hood and vent outside with ducting.

[Kevin Midgley]

Many decades ago I heard the story of a guy who did soldering all the time. Didn't have a fan system and developed the habit of physically blowing the fumes away. The constant blowing changed his breathing pattern which in turn stopped the regular internal massage of the body. It killed him. The take away is to use a fan! Plus if you ever have seen what flux fumes can do to a range hood used as an extractor you would understand the need for one.
Just paint the extractor octopus of pipes bright colours and put a hood on the end of each one to collect the fumes with one central fan motor.