YUL layover and security
 

So when I did YTZ-YUL-LGA, I had to go through security twice.

Now I'm doing LGA-YUL-YTZ... if I buy alcohol at duty free at LGA, what happens when I get to YUL? I have no checked baggage so can't bring liquids through :(

As this is not an Air Canada topic it's been relocated here to the Canada forum.

tcook052
Air Canada forum moderator

If the LGA duty-free can put your booze is in a sealed duty free bag with the receipt inside, you should be OK:

http://www.catsa.gc.ca/duty-free-purchases

Haven't done it at YUL but it was fine at YVR. Or you can observe that the duty free prices at LGA are higher than they are at NYC liquor stores so just buy it ahead of time, stick it in your bag, and check it.