Sealing The Roof Penetrations On AI

[3bcamper]

It's time to re-seal the roof penetrations on my 2009 (bath fan, main fan, black and gray vents). Two questions:

1. What is the best product for this?
2. Have any of you heard of and used Vulkem?

Thanks!

P.S. I think Airstream could/should make a more elegant design that combines some of the functions into fewer and consolidated roof penetrations.

[InterBlog]

I did ours about four months ago and I've got a description in this blog post called "Re-caulking the roof of an Airstream Interstate".

To make a long story short, it was kind of a trial and error procedure, as neither my husband nor I had done anything like that before. I ended up using Sikaflex 221 which I actually grew to like as a product, although it takes a certain technique to get it on properly and it is highly unforgiving if the appropriate technique is not used. There are some messy pics in that blog post... looking back on it, I did myself a disservice by not posting pics of what the application looked like once I DID get the hang of it.


If you decide to use Sikaflex, I recommend nailing together some scrap wood pieces and doing trials on those pieces until you find a technique that works for you. My technique ended up being applying it with a thin metal spatula with a technique similar to palette knife painting (example here). I took several years of oil painting lessons as a child, so that's the approach that worked for me. Others report success with a lay-a-bead-and-then-finger-press approach.

[lewster]

SikaFlex 221 is my go-to sealant for just about every application that I have. I use it by the case!

As IB says, it does take a bit of practice to get it on correctly so that it is also a neat application. I use the gloved finger method and after pressing it into the cervices, use a rotational method similar to frosting a cake to get a nice, consistent surface.

Speaking of surfaces, preparation is key for proper application. Be sure to clean all of the surfaces that you intend to reseal with a quality degreaser. Then swab with isopropyl alcohol and wait 10-15 minutes for it all to dissipate.

Your Interstate has SikaFlex sealant on it from the factory, so there will be no compatibility problems. It also comes in white, grey and black so you can easily match what you now have.

Practice of some scrap and you will get a good looking result!

[3bcamper]

Originally Posted by InterBlog

I did ours about four months ago and I've got a description in this blog post called "Re-caulking the roof of an Airstream Interstate".



To make a long story short, it was kind of a trial and error procedure, as neither my husband nor I had done anything like that before. I ended up using Sikaflex 221 which I actually grew to like as a product, although it takes a certain technique to get it on properly and it is highly unforgiving if the appropriate technique is not used. There are some messy pics in that blog post... looking back on it, I did myself a disservice by not posting pics of what the application looked like once I DID get the hang of it.





If you decide to use Sikaflex, I recommend nailing together some scrap wood pieces and doing trials on those pieces until you find a technique that works for you. My technique ended up being applying it with a thin metal spatula with a technique similar to palette knife painting (example here). I took several years of oil painting lessons as a child, so that's the approach that worked for me. Others report success with a lay-a-bead-and-then-finger-press approach.

Thank you for this information. That looks like a single component polyurethane as is the Vulkem. The blog post confirms every thing I have experienced with the fittings, especially the quality of Airstream roof penetrations.

[3bcamper]

Originally Posted by lewster

SikaFlex 221 is my go-to sealant for just about every application that I have. I use it by the case!



As IB says, it does take a bit of practice to get it on correctly so that it is also a neat application. I use the gloved finger method and after pressing it into the cervices, use a rotational method similar to frosting a cake to get a nice, consistent surface.



Speaking of surfaces, preparation is key for proper application. Be sure to clean all of the surfaces that you intend to reseal with a quality degreaser. Then swab with isopropyl alcohol and wait 10-15 minutes for it all to dissipate.



Your Interstate has SikaFlex sealant on it from the factory, so there will be no compatibility problems. It also comes in white, grey and black so you can easily match what you now have.



Practice of some scrap and you will get a good looking result!

Thank you! How often do you find the roof penetrations require re-sealing?

[LB_3]

I thought that sikaflex 221 was self leveling like the previous caulking. It is not and the result is that mess you see in IB's blog post. She should amend that post with how she stripped my not so handiwork and re-did it.

[InterBlog]

Originally Posted by 3bcamper

Thank you! How often do you find the roof penetrations require re-sealing?

We have owned our 2007 Interstate (as second owners) for 2.5 years and so I've only had to do it one time thus far. It had been done using another unknown compound (which you can see from the blog post that I stripped off) right before we bought it.

What I noticed is that, once the previous caulk started to break down, it proceeded at an accelerating rate. So it looked solid for a long time, until very suddenly it did not. It's a good idea to keep an eye on sealants for this reason.

[Sebtown]

I use Dicor self leveling and check my roof penetrations a few times a year. I reapply as necessary. I agree with IB that everything looks good until suddenly it doesn't.

[3bcamper]

Originally Posted by Sebtown

I use Dicor self leveling and check my roof penetrations a few times a year. I reapply as necessary. I agree with IB that everything looks good until suddenly it doesn't.

Thank you. I used a single component polyurethane, and it held up under the 12 hour rain last night and today, so we're good for now. Now I know to inspect regularly. Thanks for the insight and advice. Now to get Airstream to redesign the penetration scheme.