Water in Cabover!

Explorer1016 wrote:
We used a high 7000 cfm blower door system designed for energy audits of residential and commercial buildings.

I looked those up and they look like this:


I'd like to have my own tester. Sealtech Manufacturing Company makes the $4000 one used by good RV shops. Yep. Four Grand. What can I build for less that'll pressurize an RV?

I've heard that some have been able to do a pressure test with their Fantastic Vent set on IN and High. Our 31-ft has two. FantasticVent shows its flow at 920 cfm. Harbor Fright has an 8" portable blower rated 1700 cfm. The webpage for that commercial door tester showed capacity a pinch below 7000 cfm but the test they showed in a video showed it was testing properly at 2200 cfm. RV is much smaller.

Maybe I'll go do a trial...

When I bought my 'C' new about 10 years ago, the folks at the dealer told me that they needed to seal around the marker lights before I could have it. They said that the manufacturers use power screwdrivers when installing them and it creates hairline cracks around the openings when they over tighten. It happens so often that they fix it before it happens on new units.

j-d wrote:

Explorer1016 wrote:
We used a high 7000 cfm blower door system designed for energy audits of residential and commercial buildings.

I looked those up and they look like this:


I'd like to have my own tester. Sealtech Manufacturing Company makes the $4000 one used by good RV shops. Yep. Four Grand. What can I build for less that'll pressurize an RV?

I've heard that some have been able to do a pressure test with their Fantastic Vents set on IN and High. Our 31-ft has two. Maybe I'll go do a trial...

Yep JD, this isn't the exact model but this is what we used. It has so much volume we were a bit nervous we would blow out a skylight or suck one in. Never did put on hi speed. The one we used had a computerized barometer/atmospheric monitor attached to it and we controlled it with a wifi module and watched all of the pressures and controlled the fan speed and direction from an iphone while we were on the roof spraying soapy water. When we discovered a leak we didn't get any baby bubbles, we saw BIG 3" to 6" bubbles coming out of the leaking seal areas. It was very reassuring to be able to find any voids and know for a fact you would find the leak. Leaf blowers, box fans and fantastic fans just cannot produce enough volume of air to pressurize the inside of an RV to be competent.

Do you remember the air flow the unit was producing, and the pressure it produced in the RV, from the control display?

I watched a test done on our RV with a Sealtech machine. I didn't look at numbers, but I can say the pressure difference, inside to outside, wasn't noticeable. It was nice that there was so much air volume. No waiting for coach to pressurize.

I didn't expect the door tester to use a fan-bladed blower, thought it'd be squirrel cage like Sealtech.

How'd you adapt the tester to the RV doorway? The ones I looked up only had square frames that made square corners. The big version of Sealtech stays outside and pressurizes the RV through the door. Had a rounded frame at the top.

j-d wrote:
Do you remember the air flow the unit was producing, and the pressure it produced in the RV, from the control display?

I watched a test done on our RV with a Sealtech machine. I didn't look at numbers, but I can say the pressure difference, inside to outside, wasn't noticeable. It was nice that there was so much air volume. No waiting for coach to pressurize.

I didn't expect the door tester to use a fan-bladed blower, thought it'd be squirrel cage like Sealtech.

How'd you adapt the tester to the RV doorway? The ones I looked up only had square frames that made square corners. The big version of Sealtech stays outside and pressurizes the RV through the door. Had a rounded frame at the top.

The red nylon curtain in your picture is what we used to block the pass thru from cab to coach. Since I have a Super C, my pass through from cab to coach is smaller than a typical C. My pass through is very similar in size and design as an Earth Roamer pass through.

We took the curtain and literally duct taped it to the interior of my cab. It would hold for awhile but we had to reapply the tape a couple times. It held suprisingly well though. Our bedroom is in the cabover so I pushed the top of the curtain under my mattress and taped the 2 sides and the bottom with multiple layers of duct tape.

My friend was operating the blower (it was his gear) and the last reading I saw was -40bars when we were in negative pressure. I did not see the iphone when we were on the roof and in positive pressure mode. I was so satisfied with the results. Since leaks are difficult to locate with certainty, I felt as though I could see through the looking glass and knew beyond any doubt we found some culprits.

We also performed a smoke test (under negative pressure) and an IR moisture test with a FLIR IR Camera. We literally had $10,000.00 worth of equipment inside my rig on saturday. High tech and scientific!

Sorry about the format of these pictures. This is how they were emailed to me and even after I rotated them and saved them, they are back to original rotation.

You can see the unmistakable bubbles at the leak spots. To look at the sealant on my marker lights the naked eye would believe the sealant is intact and holding. These pictures do not lie.

Just wanted to give update on problem. Since it was below zero up here at the time I took RV to local rv place. Well, they found leak and fixed it. There was no other damage. I was happy to find out it was only $100. Not bad when i couldnt get to it myself. Thanks everyone for advice.

That's good news!
Thanks for the follow up.

Dennis