Welding Tips and Tricks

Hi guys,

Stupid question but do you need to provide hood ventilation during tig welding steel/aluminium? Any fumes to be concerned about? (not including galv)

I know tig relies on the gas coverage to provide the oxide-free weld, hence my question.

Thanks
Andy

I dont use a fume extractor, personally, but sometimes the smell just gets to me. A fume extractor is definitely a plus, but not a necessity.

If you're doing production work at a bench in an enclosed (not totally open like at a table in the middle of the shop) cell then yes, I would recommend one. We had one in every booth in our TIG class at school, but in Fab we did not due to the fact that the tables had enough air movement around them and there were only one or two people welding at any given moment.

At the industrial level, fume hoods, respirators, or powerd filtered air are commonly required for stainless steels (to protect from hexavalent chromium), but rarely for aluminum and carbon steel, as the by-products are usually well below harmful levels.

In a typical repair shop, where stainless is an occasional, short-term job, the exposure limits don't usually require protection.

If it's not dictated by your employer, use your own best judgement.

Steve S

Otto Nobedder wrote:At the industrial level, fume hoods, respirators, or powerd filtered air are commonly required for stainless steels (to protect from hexavalent chromium), but rarely for aluminum and carbon steel, as the by-products are usually well below harmful levels.

In a typical repair shop, where stainless is an occasional, short-term job, the exposure limits don't usually require protection.

If it's not dictated by your employer, use your own best judgement.

Steve S

That's about what I thought too, then one of the welders on weldingweb got very sick welding a lot of aluminum.

He had to buy a small welding "smoke sucker" air cleaner to solve the problem.

MinnesotaDave wrote:That's about what I thought too, then one of the welders on weldingweb got very sick welding a lot of aluminum.

He had to buy a small welding "smoke sucker" air cleaner to solve the problem.

That's a new one on me. I spent three months welding aluminum pipe spools 10-12 hours a day on the bench without any issue. I did not have any auxilliary ventilation of any kind.

Steve S

You guys are more durable than me. I get wicked headaches from the shielding gas. I put up general room ventilation for that reason.

Tater wrote:You guys are more durable than me. I get wicked headaches from the shielding gas. I put up general room ventilation for that reason.

I use to think I was durable - now I'm on medication for COPD at age 44 - and I've never smoked.

@Tater,
I'm not sure what size room you're welding in but if your room is 10x10x8 high (800 Cubic ft.) it would take at least 2 hrs. of steady welding @ 20CFH to displace 5% of the oxygen in the room, the common amount diplaced before physical effects are noticable. That's if there is absolutely no fresh air exchange. I'm guessing that you're felling the effects of the fumes from the metal being welded more than the effects from the cover gas.

Len

Braehill wrote:@Tater,
I'm not sure what size room you're welding in but if your room is 10x10x8 high (800 Cubic ft.) it would take at least 2 hrs. of steady welding @ 20CFH to displace 5% of the oxygen in the room, the common amount diplaced before physical effects are noticable. That's if there is absolutely no fresh air exchange. I'm guessing that you're felling the effects of the fumes from the metal being welded more than the effects from the cover gas.

Len

That's pretty interesting, I was unaware of the 5% displacement measurement for noticeable effect.

@Dave,
With your condition, you would more than likely feel the effects at a much higher level, it's what you are taking in that matters most. Divers can and do lower their intake percentage because of the pressure makes it easier to take in Oxygen, they regulate it for different depths.

Normal air contains around 21% Oxygen and Higher elevations contain sometimes down to around 19%. I guess it all depends on what elevation you start out at but it usually around 5% when your head starts pounding.

Len

I have a fan blowing air on my legs to move a little air and tilt it up as much as I can get away with without effecting my gas. It moves enough air to keep me cool and give fresh air in my area.

A typical O2 meter will alarm at 19.5%, well above a hazardous level.

I would suspect, with the headaches described before, it's increasing CO2 levels in a closed-in space. While most people understand that O2 down to about 16% can be handled (with awareness), CO2 is almost as toxic as CO when it builds up.

Just speculation, though.

Steve S

Thank you, Len, you must be right. I need to stay back away from my work instead of hovering over it too closely. Have little mobility or feeling in my left (torch) hand, it fatigues quickly, so the whole process goes slow. That's why I'm still working on it. Good thing I have a regular job.

I don't need to be smart- I just need smart pals.

Thanks for all the very interesting and useful information guys. Been on a job for a week so playing catch-up.