Just blew $400 on a 'high-temp' respirator filter that started melting after one shift on the cupola.

3 comments

3 Comments

Sounds like you got a filter not rated for actual foundry work. Those high temp labels can be misleading if they don't list a specific heat rating. For cupola fumes you need something like a P100 rated for molten metal operations, not just general heat. The melting means it was probably a cheap chemical cartridge with plastic parts. A proper one should have a full silicone face piece and all metal hardware.

nina_ramirez2mo ago

Used to think any mask labeled high temp was good enough. Your point about the plastic parts melting makes it clear why that's wrong. Gonna check for that metal hardware next time.

dakota_fox2mo ago

Oh man, I mean that's a good point but I think @wood.andrew might be overselling the P100 thing a bit. Idk about you but I've seen plenty of P100s with plastic clips that just aren't gonna hold up to actual foundry heat, even if the filter itself is rated fine. Maybe it's just me but I'd actually look for something with a metal exhalation valve cover too, not just the hardware on the straps. I had a cheaper one where the plastic around the valve warped after a few hours near a furnace and it started leaking. The silicone face piece is definitely a must though, no argument there.