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Could one re-purpose a respirator to prevent noxious fumes from escaping? Answered

Hi there!
I have had this idea in my head for some time, especially now that I am looking into metal etching. But I am an apartment dweller, with a cat. Now, I know that this is pretty broad. So I will give a specific example: if I build this https://www.instructables.com/id/Electrolytic-Etcher/. Can I build also a tank using say, these acid-gas cartridges http://www.mcmaster.com/#5834t66/=walor0 in-line with the exhaust of a vent system to clean out the chlorine? Would this work? Would it be safe? Would it allow the relatively slow out-gas of hydrogen to disperse, or would it concentrate it? Any thoughts at all?



4 years ago

Thanks all! I actually have done no etching as yet (since college). The core idea is to be able to do etching in red metals and maybe steel without damaging my apartment, or gassing my cat or my neighbors. I cannot go to another location to do it, nor safely do it outside. I'm on the lower floor btw. The only vent is in the bath, though I do have a front window and a back one. One big concern is fumes back-flowing through the vent into other apartments, as the bath vents share a common duct. I am leaning back towards muriatic since that smell is certainly better than much more hazardous chlorine, but I'm worried about acid fogging. Any notions of any sort are most welcome!


4 years ago


Are you using Ferric chloride for the etching?

I do my etchings with a mix of hydrochloric acid and hydrogen peroxide - both can be obtained for cheap at local stores.

About 5% in volume is hydrogen peroxide, the rest hydrochloric acid at the strenght of 38%.

If in doubt vinegar works as well but I don't like the stink of vinegar ;)

If the current is not too high there will be only very faint levels of chlorine that you can smell.

You can add a simple carbon filter with a little fan as a cover if you want to get rid of all smells.

Activated charcoal for aquirium use of to filter spirits is good, filters for gas masks with carbon in them work too.


Answer 4 years ago

Thanks Downunder35m. Sodium chloride actually. Check the links, you might find it interesting.


Answer 4 years ago

You might want to check etching with hydrogen peroxide and hydrochloric acid ;)

If with your method you created cholrine gas than you use to much voltage or current.

Your way is quite slow compared to the alternatives and can't be sped up much by cranking up the power supply.

There are also alternatives for copper etching that can be re-used many times, which is good if you do more than one piece every few weeks.

In most etching processes you avoid cooking salt as a contaminant as it reacts with the byproducts.

During your etching, amoung other things, you create copper chloride, which to a part will be converted to copper hydroxide - you might have noticed the green slush on top of your basin?

Since you have a galvanic reaction it also matters what electrode you use on the other side of the tank - copper is the most obvious choice.

Give the hydrogen/acid solution a try and you might agree that it is easier than galvanic etching.

It works well for copper, steel and even for surface etching on stainless steel.

If the solution gets too weak you can add some more hydrogen peroxide and keep going.

In my tank I used a cheap aquarium pump with build in filter to remove floating particles and to remove the bubbles from the workpieces.


4 years ago

Perhaps for a while at least.

the respirator filter is intended to cope with the amount of air you may breath in, 3 or 4 ltr per min.

If you exceed this you may over tax the filter.

If your using this in a heavily contaminated atmosphere then the filter will quickly clog up.

For a laser cutter the filter is about the size of a dust bin (trash can)