Welding Indoors

[bcarlson]

Hello,

I have been doing quite a bit of welding indoors lately (it's stinking cold in Minnesota this time of year! :) ), and there tends to be a haze in the garage after I've gotten a ways. I am curious what anyone can tell me about the effects of breathing spent Argon/CO2, and/or whatever else is in that cloud... I suppose some of it is burnt oil from the steel pickling, etc.

Just trying to be cautious about long-term exposure to breathing nasty stuff...

Thanks,

Ben

[Hemirambler]

Hi Ben, I am NO EXPERT on this subject and I too have welded "indoors" from time to time. What I suually do is to "blow out the garage" after welding. This wastes heated air, but I figure it's worth it.
The BEST APPROACH would be to use an air "scrubber" designed for exactly what you are doing. Industry surplus outifts might be a place to get one cheap. - That' smy plan, but I'm still looking.

Another approach might be to get one of those "air filtration" systems they sell for woodworkers shops. I'd bet you could swap out the factory filter for a charcoal lined one or series of them - That might be better than nothing.

Just thinking out loud


Jacin in Ohio

[ChadRat]

I think just a small exhaust vent above your welding area that vents to the outside would be good. I would like to find a good setup myself.

[Hemirambler]

I think just a small exhaust vent above your welding area that vents to the outside would be good. I would like to find a good setup myself.


That may be true, but to do that with any frequency where I'm at (snow covered Ohio) in January will prove quite expensive!

Jacin in Sno-hi-o

[thefabman]

There are some very serious hazords to long term exposure to welding fumes and with some metals even short term. I have gotten very sick from not having any ventilation. Now i don't mess around. I have a 1200 cmf furnace fan blowing directly to the outside. In the winter this can really suck the heat out (faster than my 100,00btu furnace can keep up) but in the long run i am much safer.


scott

[Wray Schelin]

I 'm currently building a special dirty room in my shop. I used two existing walls in a corner, one of which already had an exhaust fan. On the other existing wall there is a window for fresh air intake. Both the exhaust fan and the window can be regulated to allow a full air flow tapering to zero flow. I then made one new wall and a partial upper wall for the last wall to close the room. The side with the partial upper wall will have a door that is 7' wide made from 1" sq tubing with skins of .025" thick aluminum sheet. The door will hinge at one end and also in the center, so you only have to open half the door to access the room which measures 8' sq.

The other interior walls will be skinned with 20 gage steel. Wth the door closed the room will not suck heated air out of my shop and all the dirty tasks can be done in the room without making a mess of my main shop. I could even sand blast in the room if I choose to. I will use it mostly for a paint spray booth for small parts and plasma cutting. It is a low buck solution to a lot of dirty and fume laden tasks. While working in the room itself it is best to use a fresh air supply mask. I probably won't install through the wall work gloves
but they would work good with a room like this, for say sandblasting large fenders and such.

Wray

[jvo]

Ben, I've just been reading the other post on plasma cutting a few minutes ago, then read yours here. I've also wondered about breathing spent gas fumes, as well as welding smoke. This past winter, I did a lot of migging and tigging, and quite often had a headache the next morning. Not a real bad headache, just enough to make me wonder if it was from the bad air. I don't have a positive ventilation system yet, either, and also do like Jacin does. Open up a 16 foot wide garage door even at -35*C outside to clear the air. It gets real cold real fast, but I have to in order to continue breathing. I got an old furnace that I cut down and plan on installing. Will this much air displacement cause problems with tig welding and pulling the gas away from the torch, kind of like welding in a small breeze? I know I need to do something. Getting nervous about health now. John V.O.

[Jeff Parker]

Lets see if the pics come up...

http://hotrodders.com/journal_photos/00015555/thumb_11079587390.jpg

http://hotrodders.com/journal_photos/00015555/thumb_10922364900.jpg

They are pics of my welding bench. I have considered hanging a range hood over the top, with the vent going outside to reduce the dirt/noxious fumes.


The pics come out small, but you can get the idea. All the slag goes to the sheetmetal box on the bottom.

[azmetalburner]

if you cant for some reason vent your work area, you can buy a resperator welding hood combo. they work well and use replacable cartriges. places like grainger sell them for between $200 and $300. but you still need to have some sort of air turn over. they are not oxygen supplied.
Fred

[Boogiemanz1]

Hey Jeff, I like your welding table a lot. I had not considered the collection portion. That table would be good for cutting and welding. Too bad that a guy couldn't use some sort of dust collector off the back side or the top. Delta makes a shop air system that is supposed to clean the air, I wonder if anyone has tried something like this...........john

http://www.internationaltool.com/indexair.htm

[dauer]

Hey...

I have worked in a body shop that had a mobil fume extractor made by Lincoln that really worked great! This is a link to the Lincoln website where they list the environmental systems, they are pricy but your health is priceless! http://www.mylincolnelectric.com/Catalog/equipmentseries.asp?browse=103|1010|

Dave

[Timmy_k]

This info is straight from OSHA:

Welding Health Hazards

I. CHEMICAL AGENTS

ZINC

Zinc is used in large quantities in the manufacture of brass, galvanized metals, and various other alloys. Inhalation of zinc oxide fumes can occur when welding or cutting on zinc-coated metals. Exposure to these fumes is known to cause metal fume fever. Symptoms of metal fume fever are very similar to those of common influenza. They include fever (rarely exceeding 102o F), chills, nausea, dryness of the throat, cough, fatigue, and general weakness and aching of the head and body. The victim may sweat profusely for a few hours, after which the body temperature begins to return to normal. The symptoms of metal fume fever have rarely, if ever, lasted beyond 24 hours. The subject can then appear to be more susceptible to the onset of this condition on Mondays or on weekdays following a holiday than they are on other days.

CADMIUM

Cadmium is used frequently as a rust-preventive coating on steel and also as an alloying element. Acute exposures to high concentrations or cadmium fumes can produce severe lung irritation, pulmonary edema, and in some cases, death. Long-term exposure to low levels of cadmium in air can result in emphysema (a disease affecting the ability of the lung to absorb oxygen) and can damage the kidneys. Cadmium is classified by OSHA, NIOSH, and EPA as a potential human carcinogen.

BERYLLIUM

Beryllium is sometimes used as a alloying element with copper and other base metals. Acute exposure to high concentrations of beryllium can result in chemical pneumonia. Long-term exposure can result in shortness of breath, chronic cough, and significant weight loss, accompanied by fatigue and general weakness.

IRON OXIDE

Iron is the principal alloying element in steel manufacture. During the welding process, iron oxide fumes arise from both the base metal and the electrode. The primary acute effect of this exposure is irritation of nasal passages, throat, and lungs. Although long-term exposure to iron oxide fumes may result in iron pigmentation of the lungs, most authorities agree that these iron deposits in the lung are not dangerous.

MERCURY

Mercury compounds are used to coat metals to prevent rust or inhibit foliage growth (marine paints). Under the intense heat of the arc or gas flame, mercury vapors will be produced. Exposure to these vapors may produce stomach pain, diarrhea, kidney damage, or respiratory failure. Long-term exposure may produce tremors, emotional instability, and hearing damage.

LEAD

The welding and cutting of lead-bearing alloys or metals whose surfaces have been painted with lead-based paint can generate lead oxide fumes. Inhalation and ingestion of lead oxide fumes and other lead compounds will cause lead poisoning. Symptoms include metallic taste in the mouth, loss of appetite, nausea, abdominal cramps, and insomnia. In time, anemia and general weakness, chiefly in the muscles of the wrists, develop. Lead adversely affects the brain, central nervous system, circulatory system, reproductive system, kidneys, and muscles.

FLUORIDES

Fluoride compounds are found in the coatings of several types of fluxes used in welding. Exposure to these fluxes may irritate the eyes, nose, and throat. Repeated exposure to high concentrations of fluorides in air over a long period may cause pulmonary edema (fluid in the lungs) and bone damage. Exposure to fluoride dusts and fumes has also produced skin rashes.

CHLORINATED HYDROCARBON SOLVENTS

Various chlorinated hydrocarbons are used in degreasing or other cleaning operations. The vapors of these solvents are a concern in welding and cutting because the heat and ultraviolet radiation from the arc will decompose the vapors and form highly toxic and irritating phosgene gas. (See Phosgene.)

PHOSGENE

Phosgene is formed by decomposition of chlorinated hydrocarbon solvents by ultraviolet radiation. It reacts with moisture in the lungs to produce hydrogen chloride, which in turn destroys lung tissue. For this reason, any use of chlorinated solvents should be well away from welding operations or any operation in which ultraviolet radiation or intense heat is generated.

CARBON MONOXIDE

Carbon monoxide is a gas usually formed by the incomplete combustion of various fuels. Welding and cutting may produce significant amounts of carbon monoxide. In addition, welding operations that use carbon dioxide as the inert gas shield may produce hazardous concentrations of carbon monoxide in poorly ventilated areas. This is caused by a "breakdown" of shielding gas. Carbon monoxide is odorless, colorless and tasteless and cannot be readily detected by the senses. Common symptoms of overexposure include pounding of the heart, a dull headache, flashes before the eyes, dizziness, ringing in the ears, and nausea.

OZONE

Ozone (O3) is produced by ultraviolet light from the welding arc. Ozone is produced in greater quantities by gas metal arc welding (GMAW or short-arc), gas tungsten arc welding (GTAW or heli-arc), and plasma arc cutting. Ozone is a highly active form of oxygen and can cause great irritation to all mucous membranes. Symptoms of ozone exposure include headache, chest pain, and dryness of the upper respiratory tract. Excessive exposure can cause fluid in the lungs (pulmonary edema). Both nitrogen dioxide and ozone are thought to have long-term effects on the lungs.

NITROGEN OXIDES

The ultraviolet light of the arc can produce nitrogen oxides (NO, NO2), from the nitrogen (N) and oxygen (O2) in the air. Nitrogen oxides are produced by gas metal arc welding (GMAW or short-arc), gas tungsten arc welding (GTAW or heli-arc), and plasma arc cutting. Even greater quantities are formed if the shielding gas contains nitrogen. Nitrogen dioxide (NO2), one of the oxides formed, has the greatest health effect. This gas is irritating to the eyes, nose and throat but dangerous concentrations can be inhaled without any immediate discomfort. High concentrations can cause shortness of breath, chest pain, and fluid in the lungs (pulmonary edema).

II. PHYSICAL AGENTS

ULTRAVIOLET RADIATION

Ultraviolet radiation (UV) is generated by the electric arc in the welding process. Skin exposure to UV can result in severe burns, in many cases without prior warning. UV radiation can also damage the lens of the eye. Many arc welders are aware of the condition known as "arc-eye," a sensation of sand in the eyes. This condition is caused by excessive eye exposure to UV. Exposure to ultraviolet rays may also increase the skin effects of some industrial chemicals (coal tar and cresol compounds, for example).

INFRARED RADIATION

Exposure to infrared radiation (IR), produced by the electric arc and other flame cutting equipment may heat the skin surface and the tissues immediately below the surface. Except for this effect, which can progress to thermal burns in some situations, infrared radiation is not dangerous to welders. Most welders protect themselves from IR (and UV) with a welder's helmet (or glasses) and protective clothing.

INTENSE VISIBLE LIGHT

Exposure of the human eye to intense visible light can produce adaptation, pupillary reflex, and shading of the eyes. Such actions are protective mechanisms to prevent excessive light from being focused on the retina. In the arc welding process, eye exposure to intense visible light is prevented for the most part by the welder's helmet. However, some individuals have sustained retinal damage due to careless "viewing" of the arc. At no time should the arc be observed without eye protection.

[Jeff Parker]

John (Boogiemanz)
There are more pics of this in Hotrodders.com go to Project Journals, then go to Beenawy2long. I have a few pics of the layouts for the funnel, and several other interim pics. The sides and back are removable. There are (2) 1x1 tubes that support each sides and back. They slide into a 1.25x1.25 tube welded onto the side of the table. The back has 90 bends that face forward. The top edge is hemmed for strength, and I opened the hem on the sides to interlock with the flanges on the back. (Did I confuse you?) If you need a closeup, I will post a pic.

The whole reason I built the table, was so I could weld or cut with shorts on. No burns yet....

[snotzalot]

Another approach might be to get one of those "air filtration" systems they sell for woodworkers shops.

I use one in my woodworking shop, and it does the job on welding smoke and particles too.

[hemiless]

While we are on the subject the fumes from grinding and wire wheeling metal are just as bad for you as welding fumes. The metal/carbon dust that is created act like asbestos in your lungs in the fact that the sharp bur's in the metal/carbon dust stick into the soft tissue in the lung and causes scar tissue to form and if given enough exposure lung capacity will greatly decrease. One the heavy metals are in our body it is hard for them to get out so your best bet is to limit your amount of exposure with respirators, air filter systems, etc.

Blow your nose after welding or grinding even just a short time and look at all the dust and fumes it caught. Yuck!!!

I wear a simplenorth welding hood filter (http://www.grainger.com/Grainger/productdetail.jsp?xi=xi&ItemId=1611572861&ccitem=) when I do any welding or grinding. It's cheap and easy protection. Also I live in Alaska and even in the winter I crack open the garage door and install my box fan and weld with my carhart jacket on. In the long run I'm betting that the little extra heat will be cheaper then the alternative.

Have fun and stay safe.

[jumper]

Argon and CO2 are heavier than air so they will accumulate at floor level. If there is no escape for this build up, it will eventually displace enough air that you won't have enough to breath. Bad things happen after that...

For this reason, if I ever decide to TIG weld in my basement, I'll use a helium mix for sheilding gas.

[tvand]

As Jumper posted argon is heaveir than air. A good friend of mine that runs his own weld shop was replacing the bulkheads and floor in an aluminum semi tank that had been rotted out from liquid fertilizer. The shop was vented put not well enough in the tank where he was welding. The argon built up in his lungs and caused a displacement of air and it was like he was drowning. Thankfully no long term damage but it took a couple of months for his lungs to fully purge the argon. There's enough stuff in our environment so no sense in adding what we can prevent.
Ted

[azw]

I'd like to reopen this thread to consider ways to ventilate welding fumes--and possibly paint fumes.

In the winter, welding outside is unpleasant, and I suspect that the low temperature affects the results. And even light winds can ruin the gas shielding for MIG welding.

A number of articles online recommend "local exhaust" ventilation (removing fumes by suction right at the point of origin) for welding processes, as opposed to general ventilation (opening doors and windows).

This is a particularly helpful link (see pgs 27-30). http://www.gov.mb.ca/labour/safety/pdf/welding_guide.pdf

For local exhaust, with a capture hood placed very close to the welding and flexible ducting to the exhaust fan, they recommend at least 100 cfm (generally more) across the welding arc. The hood needs to be as close as practical to the work, optimally about 1 duct diameter from the arc. They also recommend a flared cone or flange hood instead of a plain round duct used as the hood (and you'll need a lower cfm). Hoods work best if located at the side of the work rather than above. (I didn't see anything written about placing the hood below.)

So...
I was thinking of installing a wall vent, maybe something like this:
http://www.homedepot.com/cmc_upload/HDUS/EN_US/asset/images/eplus/255385_3.jpg
(That's a Broan 180 CFM White Wall Bath Fan, Model 509S, found at Home Depot.) I'd hook it up to a round duct with a jerry-rigged hood placed very near my work. I'm not sure that it's got enough flow (180 cfm).

I've tried using a inductor in-line duct booster fan, which is designed to fit in a round duct and draw more air to a room that doesn't get enough forced air (hot or cold):
http://www.homedepot.com/cmc_upload/HDUS/EN_US/asset/images/eplus/161327_3.jpg (That's the "Inductor" 8 In. In-Line Duct Booster Fan, Model DB208, carried by Home Depot.) That fan doesn't seem to have much flow, although it's rated at 210 cfm.

Has anyone come up with anything that works?

If I were to use the same fan to vent while painting, would I risk an explosion? Most of the time I use solvent-based lacquers or enamal from spray cans.

[Kerry Pinkerton]

We use a 22" box fan mounted to the wall beside the welding table. We cut a hole in the wall and have a plywood piece that slides in to close it off when we don't want to use the fan. Seems to work pretty well. The 3 speed fans cost about 15 bucks at Dollar General etc.

[Avalonjr]

I'm skeptical about any cartridge filter being able to extract any fumes. Unless the air is flowing through a bed of activated charcoal, or the machine is using a scrubber (water mist), my feeling is that these extractors are only removing particulate matter and not chemical fumes. It would be like trying to dehumidify your shop with a furnace filter.... it aint going to happen.

IMHO the extractor must pump the air to the outdoors to be really safe. As a courtesy to your neighbors and to keep the ducts clean, a filter should be used at the inlet of the fan. To reintroduce this air into the shop would be asking for trouble.

The international tool units are listed as air cleaners and dust collectors. Probably good for wood workers, but I'd be concerned when welding. If you can still smell the chemicals, you're breathing them. This is true for vapors, fumes, smoke.

I enjoyed this thread. It is prompting me to build a fume extraction system for my shop. I've got a couple of squirrel cage fans from old furnaces. I was going to just mount one to the side wall of the shop over the welding bench, but after reading azw's labor safety article, I'm going to put the fan in a plenum box and hook up flexible duct to a cone for localized exhaust. The exhaust of the fan will be routed outdoors.

I'm a little concerned about the cfm of the air movement disturbing the shielding gas, but I'm going to follow the specs and see how it works out.

[azw]

Those are both interesting ideas.

What do you think about using the same squirrel cage or box fans for paint fumes? Would that be inviting an explosion?

[Ron Naida]

Those are both interesting ideas.

What do you think about using the same squirrel cage or box fans for paint fumes? Would that be inviting an explosion?

Possible explosion you bet. You need explosion proof rated equipment which does not produce or contains the spark while running or switching.
Check NEC ( national electrical code) book. Your library should have one.

Ron Naida

[Avalonjr]

TEFC motors are rated for explosive atmospheres, if my memory serves me correctly. (Totally Enclosed Fan Cooled)

The trick to this is keeping concentrations below the LEL (Lower Explosive Limit) of whatever you're using. If you have a fan rolling along and the air is being replaced with clean air, as long as you have sufficient changes, the vapors should be continuously diluted. The concentration should not get great enough to present an explosive condition due to the dilution.

Electrical discharge from the hydrocarbons flowing through your paint gun are another source of spark ignition when spraying.

Back to the fan... if you aren't up to buying a TEFC motor, another option is to mount the fan so that it is pushing the air into the spray booth as opposed to pulling it out. If the motor is in the clean air space (outside the booth), any sparking from the motor is not in the vapor stream and thus not part of the equation. Be sure to mount filters on the suction of the fan so that you're not blowing dust into the booth.

Friends of mine have built temporary spray booths in their garages by building a wall of 2x4's and stapled furnace filters to the framing. The wall is then hinged to the ceiling. When they spray, the wall is unhooked and lowered down, forming the spray booth. Since the entire wall is "filtered" the air moves from the fan (through its inlet filter), across the spray booth and out the filtered wall. The filters capture all of the overspray paint particles and the vapors keep on moving... through the garage doors and outside. Since the overspray is captured, the booth air remains clear and breathable. We still use filter respirators and googles while spraying, but it is an effective system.

[Boogiemanz1]

In one small spray booth I built, I used a belt driven squirrel cage fan with the pulley side blocked off by sheet metal. I had the other side screwed to a board with a hole the size of the round opening, and then screwed the board over a corresponding hole in the booth. When the fan was on, it pulled the air out of the booth through the squirrel cage to a square duct out the wall.

Inside the booth I installed a grill that had adjustable flaps over the opening. This allowed me to tailor the amount of air flow across the booth. Filter boxes were in the booth wall and outside at the end of the duct....................john

[azw]

After reading AvalonJr's message, I wondered what the LEL (Lowest Explosive Level) was for common chemicals. Here's what I found.

Chemical, lower flammable limit, upper flammable limit (percentage volume of air)
-----------------------------------------------------------------------

Acetaldehyde, 4.0, 60
Acetone, 2.6, 12.8
Benzene, 1.3, 7.1
Carbon disulfide, 1.3, 50.0
Cyclohexane, 1.3, 8.0
Diesel, 0.8, 6
Diethyl ether, 1.9, 36.0
Ethyl alcohol, 3.3, 19.0
Gasoline, 1.4, 7.8
n-Heptane, 1.05, 6.7
n-Hexane, 1.1, 7.5
Isopropyl alcohol, 2.0, 12.0
Methane, 5, 15
Methyl alcohol, 6.7, 36.0
Methyl ethyl ketone, 1.8, 10.0
Pentane, 1.5, 7.8
Propane, 2, 9.5
Styrene, 1.1, 6.1
Toluene, 1.2, 7.1
p-Xylene,1.1, 7.0

(Some of these numbers were different depending on the source)
major sources:
http://www.raesystems.com/~raedocs/App_Tech_Notes/App_Notes/AP-203_PIDs_and_HazMat.pdf
http://hcsintranet.osu.edu/Safety/SafetyWoo/CHP/table3.pdf
http://www.worksafesask.ca/files/ont_eusa/entry.pdf

These LELs seem very low, so the risk must be real, as Ron Naida said.

[Ron Naida]

Back in the 80's one of those loss control reps from my insurance company came into the shop and we got to talking.

A home built booth had to have two layers of drywall for fire, lites had to be covered with that glass with wire inside. So if you swung something you could not access the bulbs and cause a spark.
Switches had to be outside the booth.
If you have any concern about sparks from electrical devices you can put in an explosion proof junction box. That's a box between the device and the hazardous area. You fill it with a epoxy mix and it seals the conduit preventing a spark from following the wire path.

TEFC motors were mentioned by someone but I think the motors rated for hazardous location use have more strict requirements. Like the heat the outside case is allowed to generate in extended use.

I am not up to date on this that's why I suggested read the code book.

Ron Naida

[Renee n Jerry Conrad]

We've got really good ventilation but I'm not feeling safe with just that. For those of us with smaller faces, moldex offers a size small respirator:

http://store.weldingdepot.com/cgi/weldingdepot/2850N95.html?id=eFMU4FA8 has the best price I have found.

Renée

[wagon john]

Timmy k posted a list of OSHA Welding Health Hazzards. Among the hazzards listed for long exposure to Flourides is bone damage. Can anyone explain what form of damage is done and if it is treatable? Sounds pretty scary to me. John Christensen