Well, we got almost a cubic foot of over-flow.
The first 2 cans seemed okay. I waited about an hour and probed inside the space with
a steel rod. I found that there was still gooey foam and some liquid gunk under the boiler.
I think this stuff works better out in the open air.. Not inside a tight space,
where their isn't any air coming in..
After 2 hours, it was still mushy under there, and some dirty brown liquid came out of one of the holes.
So, about 4 hours into the job, I squirted in the last two cans. No over-flow at first,
then later, about one cubic foot of over-flow came out..
The next day, I cleaned and wrapped the bottom stand in insulating tape.
The bad news:
Today, the temperature of the floor around the boiler is slightly higher than yesterday.
The heat from the boiler seems to be going into floor faster now..
My guess:
The sealer that I used around the steel skirt, might be conducting heat into the concrete floor, more efficiently..
Wasting more fuel..
We are getting a bit of sun today, so maybe I'll see if the other insulation
(on the pipes) is going to help limit the normal losses.