Get an MSDS from the school on Merlins gold, whatever that is.
Sounds like a brass that mimics gold for teaching. Silver solder does
not ordinarily contain nickel at least when we at PMWest make it. I
would be surprised if anyone else uses it. Asthma in my wife's
experience is tough to shake, even after the exposure to an irritant
is over with.
A bunch of things in a shop could annoy your lungs with asthma.
About any metal or chemical fume at all. Asthma is easily triggered I