Ventilation in the metal shop

Metal Shop
#4

Resurrecting an old thread to ask what appears to be new questions.
@ke5bud @texastboneking and others involved with the actual process with the fire marshal et. al.
Is the ventilation system REQUIRED to vent to the outside, or if we had a working filtration cart, like this one, mabye, would that satisfy the immediate requirement?

As a follow up, what is going on with the existing filter cart?

If it’s all good, could it be used in this fashion?

Or, could it be mounted in the ceiling, and have 2 branches to serve both the welding table and the plasma table?
Couple of these might just do the trick, with built-in dampers.

@MathewBusby @Tapper
And for the rest of the gallery, would this satisfy your concerns about the situation?

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#5

Specifically, I asked about welding some stainless steel and was told no due to fumes and the chromium content. I was not aware that this was such a big deal on a very occasional basis.
Would a filter address those concerns?

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#7

I just hit a very funny sequence of keys which posted and then deleted my unfinished post. That was hilarious.
Filters generally remove particulates. Some types of filters remove other things, the HEPA filter in the link is designed to remove particulates (really well, I might add). Welding fume contains both particulate and gaseous constituents. The actual content of welding fume is dependent on the metal you’re welding, the filler you’re using, the process, temperatures, etc. A general overview can be found here: https://www.osha.gov/Publications/OSHA_FS-3647_Welding.pdf

IMHO, all hot work processes should be exhausted to the outside of the building. I would guess that would require make up air, but that’s for a pro to figure out.

Edit: now i see the undelete button… Oh well.

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#8

No @jast a filtration system will not cover what is needed, and @rolbrey no you can not weld galvanized even in small amounts without severely injuring yourself and others and if it is bad enough it would be a horrible way to die. https://en.wikipedia.org/wiki/Metal_fume_fever

Ask @AlexRhodes for more info on the progress he took charge of it along with @Robert_Davidson.

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#9

Roger that. Thank you!

#10

Once Robert and I took over we were able to gather all the proper information. We talked with the fire marshall again and it is under the discretion of the Building Inspector. The Building inspector wants a Professional Engineer and that is why Robert started this thread. https://talk.dallasmakerspace.org/t/registered-professional-engineer/4927

#11

Got it. Somehow I got it in my head that the building OWNER wanted the professional engineer. I thought if we could make the Marshall happy without penetrating the roof maybe that would satisfy the building owner, and then we could see about member satisfaction. Seems like I was on the wrong track altogether. Ah well. Thank you.

#12

Here, let me make it easier to read

STAINLESS STEEL CHROMIUM.

Where did I say I want to weld zinc? Ever?

I was always surprised the welding area was not ventilated, when the laser and pottery seemed to get vented fine. And I thought the venting should be to the outside, not filtered and recirculated. I was just worried that the re circulation option was going to be the choice. I am glad to see a push for outside exhaust.

Thanks.

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#13

Ditto.
I just wish the goal was closer, and differ in opinion with some folks about what we can do while the game is afoot.

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#14

Chromium-containing metals produce hexavalent chromium during hot work processes. Hexavalent chromium is a known carcinogen.

Hot work on galvanized metals produces zinc oxide fume, which is the cause of “metal fume fever.” Best case scenario: you get a bad flu for 48 hours.

Edited for clarity.

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#15

And while he hexavalent chromium is bad, there is very little evidence online that this is a significant threat from occasional welding, let alone welding as a full time profession given at least basic ventilation, of which we currently have none, so that is a problem.

I know there is stainless welding going on at the space, I happened to ask permission and so have not done it. Maybe this needs to be formalized. This goes for grinding also.

With an exhaust in the metal shop, would the space allow it?

If a welder was moved outdoors, would the space allow it?

Pretty much all welding creates dangerous fumes to some extent, especially the flux core welding prevalent in the shop.

In the case of the machine shop, if it is true that only a 6 inch hole is available, then a flexible duct and fume extractor could be used, and placed close to the welding activity.

Otherwise, rolling the welders outside, much like the forge, should be facilitated. (Maybe it is, I haven’t investigated)

Thank for your time and the improvement work in the shop. I hope the regulatory requirements are not so onerous as to eliminate any chance of improved ventilation.

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#16

Ventilation is mandated by OSHA for the pros. The minimum ventilation required is the ventilation that exposes the welder to the PEL (permissable exposure limit). OSHA allows for “natural ventilation,” but being outdoors wouldn’t necessarily provide sufficient ventilation (don’t jump offsides: I’m saying there are instances where this could be true, not that it would if DMS were to do it). I would be okay with moving it outside as it doesn’t expose other members present in the workshop to the welding fumes.

There is evidence that occupational exposure to hexavalent chromium causes severe adverse health effects, including, but not limited to, cancer. Just ask the Court that mandated OSHA reduce their Cr(VI) PEL by 90% in 2006.

The issue has become the requirement that the ventilation plan be signed and sealed by a Professional Engineer. This is required by the City of Carrollton, not something that only DMS is requiring: Ventilation in the metal shop

#17

Just FWIW while I saw it discussed, the hole in the roof seems to be larger than 6" (it was recently measured at about one @Robert_Davidson right foot length) and it’s possible the pipe coming down is only 6" via a converter at some point.

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#18

IMG_4770.jpg2448×3264 2.66 MB

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#19

Ok that’s only helpful if we know what size your shoes are. :stuck_out_tongue:

You could be size 5 or size 15. :smile:

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#20

Also, I believe OSHA regulations for ventilating this size metal shop calls for an external vent shaft at least 1 cubit in diameter. The City of Carrollton Life Safety Code demands a minimum of half a megalithic yard.

JAG “The Speed of Light in Furlongs per Fortnight” MAN

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#21

You know that hexavalent chromium has only a health safety code of 2, thus technicality not making call for a hazardous materials vent. I was jumping back & forth the other night on the international codes. I will jump back to the Professional engineer thread too to discuss. Damn building inspectors gotta make things difficult, didn’t realize that they were the ones wanting it. I do wish we could work around that engineer part since there are already systems designed for this stuff.

#22

What is this in reference to?

#23

The SDS for hexavalent chromium

Sure wish I could spell better at times.

#25

Here at the bottom of page 2 under United States EPA Regulatory Information:

https://www.eraqc.com/DesktopModules/ERAMSDS/ViewPDF.aspx?id=155b96c9-3b91-4b0f-8fb9-4589ba4cb658

JAG “A Hex On Your Chromium” MAN