Leak, my homemade Sealtech attempt, & question

I did the same with an old furnace blower. I went through a pass through cargo door.



The first time I did the test, I found so many leaks I recaulked the whole trailer. I used Eternabond on all the roof seams. I just rechecked it this year and was good to go.

As far as soap, I used water with dish soap and baby shampoo. Not sure about proportions, but bubbles will show up.