I don't have a J-Mate either, but I do have a sun funnel that I built for the 2017 solar eclipse. Unfortunately, I also have a forecast for 75% cloud cover Monday morning. But if there's a break in the clouds, I'll have it ready.
I got a break in the clouds! Not long enough to get a good focused photo, but long enough to see Mercury. The other spots are on the screen, not on the sun.