Leaks galore

What do you do to mark each spot until you're done with your test? I'm thinking a piece of blue painters tape, but it would not stick to a wet soapy surface. You would somehow have to mark each spot and then go back over the trailer with caulk after you were done with the test.

I have the largest hand-held, gas powered, blower that Stihl makes, so I'm thinking I could do this through the cargo door, propping up my DS's bunk bed a couple inches.

Before I start testing, I take five pieces of paper and crudely draw out the four walls and the roof. I mark with a pen, the location of any leaks.

Yes a large blower will probably get the pressure differential needed. I made a DIY manometer using a piece of 1/2" acrylic tube and a piece of plywood. Make a "U" with the tube and attach it to the plywood. I fill the tube with water and food coloring. One end of the tube is inserted into the blower mounting board and the other end of the tube is open. I mark on the plywood the water levels before testing with some marks at 1/2" increments from resting center. The measurement is the sum of the higher level and lower level from center in the tube when testing.

The Westend MZ1000 manometer:



The squirrel cage blower I use is positioned on a ladder and the air is directed through a window:



For my first tests I blocked off the ceiling vents with cardboard and tape. My heater stack is fed from the outside and I put a towel around the bottom of the combustion chamber. Sinks and toilet are filled with water. After a couple of tests, I kind of slack on the sealing since the squirrel cage pushes a lot of air. YMMV.

FWIW, my trailer has a full vapor barrier on the interior. Air still enters the wall and ceiling cavities, enough to make bubbles where there is any through hole in the exterior.

When I did the restoration on the trailer, I tried to seal all the mating surfaces diligently. I did have a few small leaks. I continue to test at least yearly as I don't want my work to be undone.