Anyone use a smoke bomb for RV leak testing

[larry2c]

I have another thread going about a leak in our Cruise Lite and I was thinking of doing a leak test before taping things up with Eternabond. I see these Superior Smoke bombs and was wondering if anyone had used them. If so, how did it work out for you and did it leave any residue to clean up?

[woo10-210]

Get a smoke generator (non-toxic) from a party supply store (Party City, Michaels) or rent one. Close all doors, windows, etc. With a ceiling vent fan on high speed, go around all of the exterior points of entry with the smoke generator. You can also rig up a box fan on the screen door to exhaust the air.

[bikendan]

I would find a shop that does the Sealtech test, before I would release a smoke bomb in my rig.

[rsdata]

I believe I would tape off all doors, and outside vents except for ONE and hook up a 5 Hp SHop Vac ( on exhaust blowing), or maybe a leaf blower pointing into the camper, then crawl around on the roof with a soapy water squirt bottle and look for leaks that way. I believe smoke would NOT be good inside the camper.

[woo10-210]

Smoke/fog generators use a mixture of distilled water and vegetable glycerine so it's non-toxic and doesn't leave an odor. Usually purchased pre-mixed but it can be made DIY. These same machines are used to test air infiltration of residential and commercial windows and doors.

Another alternative for the air flow is an electric leaf blower through a window. Seal it in place with plastic trash bags and masking tape. You want to blow the air out to draw air inward through leaks and minimize the fog going in.

Oops. I see RSDATA also suggested a leaf blower.

[larry2c]

Thanks for the suggestions all.

I see some folks say to make the interior pressurized and others say make the interior negative pressure. I can see how pressurizing the interior would work and you could use the soapy water spray like looking for a leak on a tire. Not sure how you track a leak with negative pressure on the interior. Can someone explain that one a little better?

[woo10-210]

Originally Posted by larry2c

Thanks for the suggestions all.

I see some folks say to make the interior pressurized and others say make the interior negative pressure. I can see how pressurizing the interior would work and you could use the soapy water spray like looking for a leak on a tire. Not sure how you track a leak with negative pressure on the interior. Can someone explain that one a little better?

That's how we test buildings. Run negative pressure on the interior and fog the outside to see where the fog enters. The exterior of buildings are almost always under positive pressure due to winds and breezes. RV's are no different. Since RV exterior doors, pop-out windows, roof vents, range fan vents, etc. open outwards, pressurizing the interior will push them off the seals.

[TitanMike]

Originally Posted by larry2c

Thanks for the suggestions all.

I see some folks say to make the interior pressurized and others say make the interior negative pressure. I can see how pressurizing the interior would work and you could use the soapy water spray like looking for a leak on a tire. Not sure how you track a leak with negative pressure on the interior. Can someone explain that one a little better?

If you don't pressurize the inside you will find few leaks with a smoke generator.

Best method is to pressurize with leaf blower or shop vac and use the spray bottle method. Relying on smoke to flow from a leak at normal pressure will work if it's a huge leak. Pressure will reveal the small ones that are often the biggest problem.

I have an inexpensive "Worx" electric leaf blower that puts out a ton of air. If I were to do this test I'd cut a small piece of thin plywood to fit one of my smallest outside storage doors. cut a hole in the middle I could stuff the tapered nozzle of the blower in and tape the plywood to the door opening with some gorilla tape. All my outside storage areas are directly connected to the interior. Make sure vent over stove is locked closed and all windows are closed tight Plug it in, let the inside pressurize then hit every possible leak point with water/dish soap solution. Mark leaks with some painter's tape and then make sure they are clean/dry when you come back to repair.

Also, make sure the P-Traps in sink and shower are full of water or close stoppers. Better yet, do both or lots of pressure will escape up vent pipes.

As for making inside pressure lower than outside, this may help if you are sealing with a self leveling lap seal. It will suck material into leaking area but how much help, don't know.

On the East side of our State where they have Controlled Atmosphere storage for apples, they use a shop vac to vacuum down the huge warehouses and then employees go around and check every seam in the walls. Leaks will "Hiss" and they're marked for repair. These "CA Warehouses" are filled with nitrogen (machinery removes oxygen) to keep apples from spoiling so they have to be as air-tight as possible. THERE they use low pressure inside. RV leak detecting uses positive pressure inside to do so.

[Wolf26]

Sometimes I would like to use a real bomb !

[gailrich]

What I did was tape all diffusers in RV on rooftop acs then ran both fans on high and found the leak in 15 mins. It was from rooftop winegard antenna does any have any reason why and a solution I would greatly appreciated he help.
Thank you

[gailrich]

See pics for the prior post. Please help.

[larry2c]

I tried the leaf blower and I sealed up all the vents etc. that I could think of. It did seem to be fairly pressurized because if I flipped the latch on the kitchen stove vent, it blew right open. I sprayed around near where I thought the leak would be but didn't get a bubble.

I decided to clean up the original factory seagull poop sealant on the joint between the front fascia and the roof and seal it up with 6" Eternabond. During the cleanup I did find an area that looked like the Dicor had gaps in it. If it was leaking there, the place where I was finding the water inside the TT was downhill from that point. Since sealing that joint, we have had three light to medium rains and no leaking. I'm cautiously optimistic!

I know I should have spray checked more places and I may rig it up again in the future. Thanks for sharing your pics of your leak - good example!

[jd50i]

On my 6X12 enclosed trailer, I used a shop vac to find a leak. Fairly simple, I cut some closed cell Styrofoam to fit in the vent and taped it up, ran the vacuum line from a small shop vac through the Styrofoam along with the cord and used that to pressurize it. found the leak in 30 seconds.