Is it a safe practice to hot cut galvanized uni-strut, hat channel, etc. with a friction cut off saw [chop saw]. Someone on a jobsite pointed out you can’t weld the stuff because of toxic fumes in a closed environment and that the yellowish smoke coming off the saw look the same.
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Lots of ventliation and drink a lot of milk...
You will get a world class sinus infection (ventilation) and yur kidneys will try kill to you.. (milk to help you out here)
Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming
WOW!!! What a Ride!
Not exactly the same situation, I think yours is less severe, but when I was learning how to weld the manuals all said that ventilation and a simple dust mask would provide sufficient protection.
A fan blowing across the saw with good general ventilation would be sufficient. If the space was more confined and the exposure greater wearing a simple P-95 rated dust mask would likely be adequate.
If you did a whole lot of this in poorly ventilated spaces a half-face mask with a HEPA cartridge would be the next step up. This was the recommended rig used when regularly welding galvanized steel for hours at a time.
Milk helps. Not just in countering the zinc compounds but also against the manganese exposure more common in welding. The manganese is antagonistic to magnesium absorption and in high concentrations the result can be mood swings, personality changes and even psychosis.
when I was learning how to weld the manuals all said that ventilation and a simple dust mask would provide sufficient protection.
Dust mask would only protect you from breathing in large particles, wouldn't an activated charcoal mask make more sense?
What's the difference between P95 and N95?
difference between 'N' and 'P' types are how well they handle an oil mist. 'P' types are designed not to degrade then exposed to oil, petroleum, and they may, according to one source I read, less prone to clog when exposed to an oil mist.IMHO anything dealing with metal working is best to use 'P' rated filters as metals often are coated with oil or use oil as a coolant during treatment or tooling.The vaporized zinc rapidly forms a fine dust. After welding galvanized steel you can often see this white or yellow powder around the weld. The activated carbon filter is designed to absorb vapors and gasses. A less expensive and longer lasting, carbon looses effectiveness one exposed to normal, polluted, air, filtration units are IMHO what you want.
It seems all I weld or cut is galvanized pipe, for gate frames or backstops and the smoke is pretty heavy when welding. I've never noticed any issues with cutting it with a chop saw, but I try to use a Porta-Band. Much less noise.
Reportedly, the smoke causes a reaction called metal fume fever, which as I understand, has no long term effects, but if I weld in my shop even with decent ventilation, my lungs feel tight that night. Stands to reason, since while your welding your head is usually only about 12" from the weld so the majority of the smoke goes right up your nose anyway.
I've heard of the milk trick, and tried raw potatoes on my eyes after I burned them welding once, and don't think it really helped. That was the worst night I can remember in awhile.
I don't think I would worry about cutting uni-strut with a chopsaw though.
Cole
Cole Dean
Dean Contracting