Resealing Airstream plumbing vent

[SilverGate]

I saw cracking of our 2007 Airstream Safari rooftop plumbing vent sealant while standing on a ladder and doing our annual "Wash, wax and treat II" last month. After 8 years of subjecting Airstream's original rooftop Dicor sealant to the hot sun's rays of the Southwest, it was now time to replace cracked sealant with Sikaflex 221. (See AirForums' thread, "Exhaust pipe for plumbing [sealant]".)

Tools that I used:

A new tube of Sikaflex 221 Multi-Purpose Polyurethane Sealant/Adhesive (Note: The shelf-life of Sikaflex is 12 months from the date of manufacture.)
caulk gun
plastic scraper
isopropyl alcohol (mineral spirits can also be used)
a soft cloth
Airstream Life's The (nearly) Complete Guide to Airstream Maintenance

Details of the replacement of our cracked sealant are seen in my History Safari Express post, "Resealing our Airstream plumbing vent."

Also see:

How To Prevent RV Roof Leaks

[subfan1]

Very nice SilverGate, will you be doing the roof vents, TV antenna? Was the old stuff hard to remove?
Thx

[SilverGate]

Originally Posted by subfan1

Very nice SilverGate, will you be doing the roof vents, TV antenna? Was the old stuff hard to remove?
Thx

Thank you!

Five years ago, I sealed the Fan-Tastic Fan and bathroom air vent seals with Tempro 635 (which is similar to Sikaflex 221). See details in my post, "Fall Safari prep." I do an annual inspection at the time of my annual wash and wax and only remove sealant if it shows signs of cracks or deterioration.

In my latest resealing with Sikaflex, I used isopropyl alcohol to soften the cracked sealant, which was scraped off using "elbow grease."

[Siegmann]

I've heard that Sikaflex and alcohol are a bad mix.

[TG Twinkie]

What do you mean by a bad mix? If it gets the old stuff off why are you concerned about the mix?

[SilverGate]

Originally Posted by Siegmann

I've heard that Sikaflex and alcohol are a bad mix.

Thanks, Siegmann. You are correct. Sikaflex 221 contains polyurethane and Sika says, "It is important to note that alcohol and their derivatives can permanently stop a polyurethane from curing. If you need to use a tooling agent to finish your Sikaflex project, a small amount of dishwashing liquid in water, and then running your finger or a tooling device along the seam to tool off is suitable."

For the most part, I just used a plastic scraper to remove the old cracked sealant and continued to use the scraper to remove the more pliant sealant underneath the surface. I mainly used a small amount of alcohol on a rag to remove any new sealant that fell on unintended places as I was applying Sikaflex to the Ventline flange.

Note: if alcohol is used to soften old sealant, the surface must be washed off with soapy water, rinsed and dried before applying new Sikaflex!

To reassure myself, I just took a ladder out on this sunny Thanksgiving Day in San Diego (as the neighbor's turkey smelled exquisite in their Smoky Joe) to inspect and photograph the plumbing vent seal and was happy to see and feel that the seal has a nice dry tough skin on it... and now for some turkey skin!

Happy Thanksgiving all!

[subfan1]

Very cool SilverGate, I need to start this project soon. With all the talk of El Niño and the rain we might be getting, it's time now for me to do this.
My AC shroud is missing the "I" and noticed you removed all the lettering or did you? If so, how did you remove the lettering?
Happy Thanksgiving to you and Larry

[SilverGate]

Originally Posted by subfan1

Very cool SilverGate, I need to start this project soon. With all the talk of El Niño and the rain we might be getting, it's time now for me to do this.

My AC shroud is missing the "I" and noticed you removed all the lettering or did you? If so, how did you remove the lettering?
Happy Thanksgiving to you and Larry

My AC shroud never had the word "Airstream" on it, so there were no letters to remove. I did a search for any AC shrouds on Airstream trailers that did have this word and I found only one photo, as seen in post #7 of the AirForums' thread, "Repairing Cracks in AC Cover."

[SilverGate]

I did not have to get onto the roof to reseal the plumbing vent, but there may be a time to get onto the roof, and it's good to know how to do it safely and without damaging the Airstream.

See Colonial Airstream's Patrick Botticelli get onto an Airstream Travel Trailer roof and give a tour while telling about what the roof is made of, along with maintenance tips and a look at Airstream's seals and the new ducted air conditioning system viewed from the top!

How to Climb onto the Airstream Trailer Roof

[guskmg]

I recently posted on another thread that the Airstream Service Center just resealed my trailer roof. It took 11 (eleven) hours to chisel (nylon chisels and rubber mallet) off the old sealant, and 8 tubes of Adseal (a silicone based sealant). Airstream is now using Adseal on the roofs and seal tape between the aluminum sheets during production. Kevin, the shop foreman, said that Adseal is the longest lasting sealant for our Texas sun.
BTW, when I got back home I found a nylon chisel laying on top of my rear, awning roll. It had apparently fallen there when they were cleaning off the old caulk. My shocks must still be good because I sure hit some hard bumps coming through the OK City on I-44 and I-35 exchange.
guskmg

[SilverGate]

Originally Posted by guskmg

I recently posted on another thread that the Airstream Service Center just resealed my trailer roof. It took 11 (eleven) hours to chisel (nylon chisels and rubber mallet) off the old sealant, and 8 tubes of Adseal (a silicone based sealant). Airstream is now using Adseal on the roofs and seal tape between the aluminum sheets during production. Kevin, the shop foreman, said that Adseal is the longest lasting sealant for our Texas sun...

The (nearly) Complete Guide to Airstream Maintenance, by Rich Luhr, mentions on page 75 that "Airstream recommends AdSeal Premium Quality Sealant for this job [typically roof seals around a plumbing vent, vent fan, or skylight]." Adseal is available online from Airstream in white or grey.

I chose Sikaflex 221 because, per the guide mentioned above, it is a good general purpose choice and is readily available.

Full story: "Resealing our Airstream plumbing vent", History Safari Express

Other recommended Airstream blogs

[Siegmann]

Originally Posted by guskmg

I recently posted on another thread that the Airstream Service Center just resealed my trailer roof. It took 11 (eleven) hours to chisel (nylon chisels and rubber mallet) off the old sealant, and 8 tubes of Adseal (a silicone based sealant).
guskmg

Eleven hours, wow! Out of curiosity, how much was the bill?

[lewster]

I have to say that during my first exposure to Adseal, I was able to remove a significant amount quite easily. I surely did not get a warm/fuzzy fealing from this and I would be very surprised if it lasted several years. I have never heard (within the industry) that it is the longest lasting sealant. Airstream is the only OEM that I have seen using this silicone based product.

ALL of the major motor home OEMs like Newmar, Newell, American Coach, Entegra Coach and others DON'T USE ADSEAL !!!!!!

Their roof sealant of choice is Alpha Sealants 1021, which is a high solids self leveling adhesive sealant that cures into a thick rubbery mass that is extremely hard to remove or SikaFlex 221.

My feeling is that the change from SikaFlex to Adseal was strictly an economic one and was not based on any long term performance data.

I still insist " beware of silicones".


Lew Farberl
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357l

[SilverGate]

Originally Posted by lewster

I have to say that during my first exposure to Adseal, I was able to remove a significant amount quite easily. I surely did not get a warm/fuzzy fealing from this and I would be very surprised if it lasted several years. I have never heard (within the industry) that it is the longest lasting sealant. Airstream is the only OEM that I have seen using this silicone based product.

ALL of the major motor home OEMs like Newmar, Newell, American Coach, Entegra Coach and others DON'T USE ADSEAL !!!!!!

Their roof sealant of choice is Alpha Sealants 1021, which is a high solids self leveling adhesive sealant that cures into a thick rubbery mass that is extremely hard to remove or SikaFlex 221.

My feeling is that the change from SikaFlex to Adseal was strictly an economic one and was not based on any long term performance data.

I still insist " beware of silicones".


Lew Farberl
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357l

Thanks for your input, Lew.

Sealants are indeed a sticky subject!

Airstream Supply sells Adseal-RTV Silicone White #4552 and says, "Adseal silicone [is] used by Airstream Factory to seal any roof mount installations, like roof vents, antennas, etc."

Note the caveat seems to be that Adseal is used on the roof of newer Airstream travel trailers, which has a different surface than the end caps and sides.

In Colonial Airstream's video below, Patrick Botticelli points out that the 0.032-inch aluminum roof panels have white paint enamel that is baked on and make good adhesive points for rooftop seals.

How to climb onto the Airstream trailer roof

[RVMS2U]

Hey guys Abe Hernandez here I use dicor self level, it seals and stays flexible for a couple of years, and way les complicated to remove, I like to replace it every 2 years and it works really well.
Happy camping and Holliday's.