Welding fumes from 2 car garage

[kansasc10]

I posted this in the shop tools section but there arent many viewers so thought Id try here.
Im welding in some floor pans in my 72 c10 using a mig setup with c25 in my attached 2 car garage. The living area of my house is on the next floor up and about 50 feet down range from the garage. The garage has 8 foot ceilings and is seperated from the lower level of the house by an exterior door. Im welding on 18ga mild steel with .030 wire at intervals of 10 minutes or less with breaks of 30 min to an hour in between for a couple hours a night. My question is, do you think the fumes from my welding are in high enough concentration to pose any risk to individuals on the next floor and 50 feet away? I know its impossible to say for sure or not but do you think it warrants clearing the house of occupants prior to welding or should I worry about it enough to invest in testing air samples? Or do you think the concentration (if any) would be so low that I shouldn't worry about it. Thanks in advance.

[palallin]

If the gasses were that much of a threat to the folks that far away, I would think you wouldn't be alive to ask the question.

[Grumpy old man]

You have a higher chance of setting your garage on fire from smoldering sparks than anyone including yourself leaning over the weld being affected . Always have fire protection ready and any flammables far enough away from your welding project . use common sense . Old carpet / seats/ rags/ etc can harbor a spark for hours before they ignite . a good Co2 and smoke alarm should be in every garage . Thinners / paint supplies / and gas for your lawn mower should be out of the garage .

[Redneck Rydes]

Flux core? or with gas? Sometimes when I weld with flux core it really has a lot of fumes,I will run a fan to act like exhaust,You will probably have more problems than inside the house!lol

[mr48chev]

As long as you are welding on clean bare metal that isn't galvanized you should be ok but my personal experience says that different people have much different tolerances for fumes of any kind.

Do you by chance have a big shop vac that you can park close to where you are welding and rig the hose as an exhaust hose to run outside under the garage door or some other spot that you can somewhat seal off while welding? Put the hose on the exhaust side and maybe get a length of pvc pipe to run the fumes out away from the garage. That shouldn't create enough breeze to effect the welding if you have the suction end three or so feet from your work but it would draw the fumes out and run them outside.

[67ChevyRedneck]

I wear a respirator welding. I'm one of the people that it bothers.

I have a similar situation, and yes, the shop smells did go into the bonus room above the garage, but would clear out quickly. Most days, if I opened the main door and back door, it always created good air flow. The issue always arose when it was really cold or windy and I had to partially close the door.

One of the biggest reasons I built my shop.

[mr48chev]

I weld outside simply because my 80+ year old garage is too small and too crowded to work in. That and the fact that I am scared to death of catching it on fire.

I'm another that fumes of any kind tend to bother.

[BigBird05]

X2 on having a good fire extinguisher on hand.

[conoco]

I know this might not help but, I Tig weld everything. No fumes to deal with as long as everything is clean and wiped down. Just a thought.

[truckster]

With a gas setup you're not creating a lot of fumes if you're welding clean steel. I wouldn't worry about it.

But I would make sure you have a fire extinguisher handy any time you're cutting, welding, or grinding.

[May70]

By definition, fumes emitted from GMAW are considered to be carcinogenic and toxic to your body. The inhalation of those fumes have a permissible exposure limit but most will not know they are (far) past that limit until they have side effects of high exposure levels. Some will have side effects earlier due to higher pulmonary sensitivities/allergies, the inverse is also known to happen.

Osha has a ton of regulations on welding. Most of them are responses to things that people did that caused bodily harm or death. Google 'osha 1910.252' and have a read over all that, by the end you should have a pretty good idea what is a good idea when welding. After you read it I suspect you are going to be a little surprised just how much there is to staying safe.

The 'safe' number is typically 100 fpm of fresh air crossing the welding area. An open door and a box fan in the window (of a small garage) and you'll probably never have an issue.

Considering most of the time with mig welding we use a 72/25 argon co2 mix, a co2 detector is always a good idea but equally as dangerous is the argon. Especially if you are welding with the torch above your head and you do not have that 100 fpm velocity of air. Argon is heavier than air. If inhaled it will go to the bottom of your lungs and disperse the air. Enough argon can fill your lungs to suffocate you. CO2 is also heavier than ambient air and will not rise up into the second level UNLESS it is being forced/pulled/pushed up there by anything such as a room with negative pressure and imperfect insulation (IE a room with an HVAC return).

What does fill the air are impurities and burn off from the process/metal being welded. That's the stuff you smell. That stuff can go anywhere, like your living space above. That 'stuff' is also carcinogenic and toxic.

You should always have a well ventilated space and you should always be wearing a respirator. Considering the living space is directly above where you are welding, you need to ensure you have a fan pulling the air from the space you are welding in and a opening across the space to allow fresh air in. Yes that means no closing up the shop to keep the heat in for hours on end. A few tacks is one thing, full on panels is a no-go.

You are going to get conflicting answers from those who never wear respirators or who have been doing it forever without too much worry. I have a degree in mechanical engineering and work as a facilities engineer (industrial shipbuilding). Everyday I work in this environment and design/construct things with this sort of thing in mind. I am also osha 30 trained. The old ways that have worked forever don't always stand up to the facts. Your health (and those around you), is nothing to gamble with.

Also if you are concerned with the fire hazards with welding, Google 'NFPA 51B'.

//

I have a 720 sqft 2 bay garage. I open both garage doors about a foot and I put a 4' drum fan at the back door to force air out. I also always wear a respirator. I have a very low tolerance of fumes so I take no chances. Heavy structural welding or a large volume of welding, I always take outside.