Fume extractor that pulls from bottom instead of top

Thread Starter

Cayliff

Joined Dec 19, 2017
1
Hello,
I am new to building electronics, but I have read allot about it. I am about to start learning how to solder first, then move on from there.

This might be a stupid question but, I am just wondering what your opinions are about it. The only fume extractors I have seen are either pulling the smoke up or towards the sides. Is there a reason why people don't put a wire mesh as part of their workbench top. and have 2 kinds of filters before a strong fan under your desk pull the fumes out.

Filter one would be just 2 sheets of metal grating. With the second ones holes offset from first one. This would keep solder that falls through the mesh from getting on the other filter.

Filter 2 would be a regular activated carbon filter,

Then there would be the fan that pull the cleaned fumes through a hole and outside.

This would free up space with the fume extractor under the workbench, and make it where you don't have to worry about where to solder that much.

What do you all think?

The only problems I see is the metal filters would slow the air down, so might be better to have a u bend in the duct that is easy to remove and clean, instead of the metal filters. This would work similar to a sinks p-trap.
 

OBW0549

Joined Mar 2, 2015
3,566
I've been building electronic thingamajigs for almost 60 years now, with soldering sessions at least once a week for most of that time. I have never used a fume extractor, yet I'm still alive and kicking-- quite nicely, in fact.

Others will no doubt differ, but my opinion is that those things are a waste except for factory workers who spend all day, every day, soldering. Spend your money on something else, like a really good soldering iron.
 

shortbus

Joined Sep 30, 2009
10,050
Is there a reason why people don't put a wire mesh as part of their workbench top
What happens when a small part drops down in the mesh? Like OBW0549 I've been soldering since a small boy, and am now 70, no problems with lead. What your smelling is the flux. If you got lead hot enough to vaporize into the air, the parts your soldering would be ruined.
 

paulktreg

Joined Jun 2, 2008
851
I'm sure you'll be fine without an extractor fan unless you do a lot of soldering.

Find a 12V computer fan or desk fan to blow the fumes away if you're worried.
 

Alec_t

Joined Sep 17, 2013
15,103
I too have survived decades without an extractor.
Soldering fumes naturally rise, so an extractor under the bench would have to fight against that and might be ineffective.
 

mcgyvr

Joined Oct 15, 2009
5,394
Soldering fumes naturally rise, so an extractor under the bench would have to fight against that and might be ineffective.
^^This..
and
This
What happens when a small part drops down in the mesh? .
However there are numerous people who are effected by the flux smoke to differing levels..
Just because you aren't negatively effected doesn't mean that no one else is either..

Those with Asthma and other health issues or just nasal/respiratory issues can be adversely effected from it and absolutely need fume extraction to be able to work around it..
The smoke can absolutely be an irritant to some and not to others..
A blanket statement they are not needed or a waste is just incorrect..
 

ElectricSpidey

Joined Dec 2, 2017
3,312
It is very hard to extract solder fumes from below, as they tend to rise very quickly. You could use a small fan directed at your work, but this tends to disturb the work.

I have been using a half face respirator and goggles for some time now.
 

Audioguru

Joined Dec 20, 2007
11,248
You said your soldering creates smoke. Then the cheap soldering iron is too hot and has no temperature control so it is incinerating the rosin in the solder instead of heating it without smoke.
My Weller soldering iron has its tip always at the correct temperature even if it sits turned on all day long. It NEVER gets too hot and does not create smoke.

Oh, it smokes if it touches plastic or my finger (ouch).
I never tried it but maybe cheap Chinese solder creates smoke. I had a cheap Chinese pcb that smelled very bad.
 
Hello,
I am new to building electronics, but I have read allot about it. I am about to start learning how to solder first, then move on from there.

This might be a stupid question but, I am just wondering what your opinions are about it. The only fume extractors I have seen are either pulling the smoke up or towards the sides. Is there a reason why people don't put a wire mesh as part of their workbench top. and have 2 kinds of filters before a strong fan under your desk pull the fumes out.....
Yes, all the cheap or DIY ones that I have seen pull as you describe from the top or sides. Even the professional fume hoods that I have used (not for soldering) work by pulling air from the top. Unless I am just missing your point, wouldn't anything like you describe require holes in the bench surface, or at a minimum, some kind of elevated platform destroying the continuity of the bench surface?

A workbench soldering area needs to be a nice solid flat surface - something that I can clutter up with abandon. :)
 

wayneh

Joined Sep 9, 2010
18,087
A down-flow hood is common for microbiological work. Sort of. The down flow is at the front glass door, to make a curtain of air that knocks any entering particles down into a filter immediately. Inside the hood's working area, there is a mild up flow into another filter. The downside of a sterile hood arrangement like this is that the worker must look through a window. That's great for micro work where you don't want any transfer whatsoever, but it would be a pain for soldering where good visibility is a must. I'd rather smell the rosin than add another obstruction to visibility.
 

shortbus

Joined Sep 30, 2009
10,050
I don't see where I ever did..
That response wasn't tied to the quote of mine you placed above it?

shortbus said:
"What happens when a small part drops down in the mesh? ."
However there are numerous people who are effected by the flux smoke to differing levels..
Just because you aren't negatively effected doesn't mean that no one else is either..

Those with Asthma and other health issues or just nasal/respiratory issues can be adversely effected from it and absolutely need fume extraction to be able to work around it..
The smoke can absolutely be an irritant to some and not to others..
A blanket statement they are not needed or a waste is just incorrect..
 

AlbertHall

Joined Jun 4, 2014
12,619
Folk can develop an allergic reaction to rosin flux and that can be very dangerous and mean no soldering, or being near any soldering, ever again. If it's a hobby then that might be a risk you're willing to take but if it's your job then that would be a serious problem.
 
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