Fume Extraction Pump DIY

Hi,

Although I'm not convinced it'll give me better health, I've pretty much had enough of breathing in solder fumes. I'm not enamoured with those bench-top fans, and have decided the route to take is via a tube that clips onto the iron: http://www.farnell.com/datasheets/318002.pdf (I use a Weller WSP80)

However, the extraction pumps cost ridiculous money. My workshop is built into a room within a double garage. Seeing as I don't need to filter the air, all I need is a vacuum pump to remove the fumes - I can then dump them harmlessly into the garage, where no-one's present.

I can get an adaptor machined so I can fit the Weller tube to the valve on the pump. The question is, what kind of pump should I go for? How would I calculate the required air flow? Could I get away with something like an aquarium pump?

I'm prepared to buy a cheaper pump than a Weller and save the bother of DIY, but no-one seems to make them.... I've found Metcal and Xytronic, but they're no cheaper.

Many thanks in advance.

Justin

If you have nearby (unmetered) running water you could simply set up a vacuum tap aspirator, like we used to do in chemistry labs. Should be enough suction to pull the fumes away from the tip, and no mucking about with oils, filters and things.

http://en.wikipedia.org/wiki/Aspirator

Cheap too...

http://www.coleparmer.co.uk/catalog/product_view.asp?sku=0637830&pfx=

Stewart,

Is that similar to a Venturi Pump?

You could probably fit a standard 100mm fan into a plywood enclosure with angled walls, connecting to some PVC tubing via a fitting. Silicone all the joints and it'll give you enough pull. Also, pop in one of the activated charcoal filters and you can vent into the room. If you use a DC fan, you could also PWM it to vary the "pull"

I had an original Farnell desktop fan in an ABS boxw/charcoal filter like this- cost £50 many moons ago. Since then, I've DIY'ed a few (same idea- ABS box, 100mm fan, fan filter on front w/charcoal filter)

It'd be good to have an on-iron type though.

Mark

Mark Burnley said:

Is that similar to a Venturi Pump?

Click to expand...

That's the fella. I'd forgotten the name.

Thanks guys. I don't have a tap nearby - not remotely. I really want an on-iron type, as shown in the Weller link. I have a plasterboard ceiling in the workshop, and the plan is to site the pump directly above my bench, with a little hole for the tube. Because it's vented into the garage, no need for a filter.

What kind of pump do I need? What should I search for?

Justin

Peter Coghlan used to use an old spare tyre blowing into a venturi junction, as an 'instant-on/instant-off' vacuum. It didn't pull a colossal 'mercury-inch' vacuum, but it was enough to suck solder fumes from a focused spot... quiet, too!

Limited by the tyre size/volume though. -He got the idea from the VW Beetle windscreen washer.

Keith

Pure Genius!

Sounds like my sort of set up-

Very "Heath(kit) Robinson"

;D

Mark

Justin,

If you're worried about the consequences of getting a puncture, or forgetting to check your spare with Keith's/Peter's idea, I'd go for a DC centrifugal fan-

Like this from RS- discontinued, but you get the idea

...you can bolt a flat piece of aly/steel across the aperture with a gasket, and then cut a hole for a suitable nozzle attachment to run to a fairly wide-bore tube, and then to your the pickup tube. Again, being DC, you could adjust the speed- and obviously make sure it runs correctly- exhausting to the centre of the centrifugal fan- causing vacuum at the aperture.

I'm planning something like this for my workshop, instead of my benchtops.

You can get these centrifugal fans cheaper on eAby too.

Mark

What about an aquarium pump?  You are starting with a tube anyway, so try something in a medium tank size.  I don't know how many CFM is good to get the smoke well.

The other option is a bathroom vent fan in the wall, which can be ducted a short distance to the bench.  There is a pricier fan that is attic mount, with ducts on both sides.  That is what I plan to rig.  Right now I have a Vornado fan and a duct to a basement window.

Definitely good to vent the smoke.  You want many years of soldering ahead of you!
Mike

The aquarium pump idea sounds good as it'll have least faffing about. However, I'm concerned it'll have enough guff.

Mark - Farnell have these: http://www.farnell.com/datasheets/35131.pdf (item no. 1568493)

The centrifugal pump idea looks good. I could find a spare t/former (or wall wart), connected to an LM317 with a pot feeding the adj pin to govern vout.

Thanks!

Justin

Justin,

That is more like a centrifugal fan than a pump.

Anyhow, I have plenty removed from large photographic printers. You must have my e-mail. Just mail me your address and I'll stick one on the post for you.