Sealants, roof, windows etc

java

Expedition Leader
Thoughts on sealants?

Butayl on the windows? Seems to last 10 years or so. Kinda nasty after it gets dusty and hot.

Sikaflex/polyurethane?

3M 4200/5200? They make UV stable now, but how good is it in reality?

What all have you guys used? Walls and roof are aluminum.
 

pugslyyy

Expedition Vehicle Engineer Guy
Thoughts on sealants?

Butayl on the windows? Seems to last 10 years or so. Kinda nasty after it gets dusty and hot.

Sikaflex/polyurethane?

3M 4200/5200? They make UV stable now, but how good is it in reality?

What all have you guys used? Walls and roof are aluminum.

Butyl tape sandwiched between two surfaces (like a windows frame and the shell of the camper)
35f5tW5.jpg


For roof stuff, Butyl tape between and eternabond or Proseal on top.
Kv7fcpB.jpg

TuE6C1c.jpg


For filling screw holes, etc, I like Marine-Tex. You can get it in gray or white and it works on aluminum and fiberglass
WAD6DQy.jpg


Even though it comes in a caulking tube, 3M 5200 is more adhesive than sealant. I've used it before but am no longer a big fan of it. If I wanted to stick something down to my roof I might use it, but I wouldn't use it in place of caulk
WrfBsKO.jpg


As with most things, the key is good prep. I pulled everything off of my camper roof this year and re-sealed everything. Warm days and/or a heat gun really help loosen up the old stuff.

This is an image of the project in progress - after bedding the roof vent in Butyl and getting ready to apply several layers of ProSeal
vxm6ZgIm.jpg
 

java

Expedition Leader
Thanks for the input!

Why did you like the 3m products? I realize they are very adhesive, but doesn't seem bad thing for roofs to me.

I used eternabond on my RV, it's OK, but not super impressed. It has come loose in places. I scrubbed the whole area with acetone before application.

I have used marine tex before, good stuff. But not really sealant.

I have a few rolls of Butayl saved, doesn't go bad does it? It's been in the garage a few years.
 

pugslyyy

Expedition Vehicle Engineer Guy
Thanks for the input!

Why did you like the 3m products? I realize they are very adhesive, but doesn't seem bad thing for roofs to me.

I used eternabond on my RV, it's OK, but not super impressed. It has come loose in places. I scrubbed the whole area with acetone before application.

I have used marine tex before, good stuff. But not really sealant.

I have a few rolls of Butayl saved, doesn't go bad does it? It's been in the garage a few years.

I carry the Eternabond for emergency repairs, but for regular use I like the Proseal. I've had the same issue with Eternabond not completely adhering and it is a pain to clean up - but it is the best way to fix something on the road (like when you poke a branch through the skin of your camper.)

5200 is more sensitive to UV than I would like. If you really want to use a 3M product then 4000 is probably a better choice.

For mounting most things I like butyl tape because it is removable. Butyl never goes bad - in fact you could probably scrape off what you have on the camper now and use it again if you really wanted to.
 

java

Expedition Leader
Completely agree, for emergency repairs eternabond is amazing. I covered every seam in it when I got out rv as ther was a leak that couldn't be pinpointed.

I'm not married to any product, hoping to start a new build and want to be informed. I needs roof vents ASAP, they are Plywood at the moment.

I have used skia products for home building, and have been impressed.

3m 4200 now has a UV stable formulation, but no idea of real world longevity.

I haven't used the proseal, but will look into it! Sounds like I have enough Butayl then, I have a few big rolls I saved.
 

java

Expedition Leader
Ok I ordered some of the pro seal in a caulk style tube. Suspiciously similar to the OSI sealant o often use.

Put one of my Maxx fans on today, did a ring of Butyl followed with a 1/4" bead of proseal. Snugged the screws down and sealed over the tops with the proseal as well.
 

steelhd

Observer
I have always used polysulfide caulks/sealants for boat thru hull fittings and never had a problem. Think that is the standard. If its good for above and below the water line in marine applications it should work great for a trailer application. I believe 3M 5200 and 4200 both fit the bill and 4200 is easier to remove if you ever need to do so.
 

IdaSHO

IDACAMPER
I refuse to use "rv" butyl.
It will ALWAYS create a mess down the road.

And using any type of sealant or adhesive can complicate things as well, as there is always a chance of needing to remove the window at some time down the road.


I use high grade weatherstrip for all of my installs, doors, windows, hatches, etc.

Sticky side down to the window flange.
Compresses and seals against the wall when the trim ring is installed.

chassis214.jpg


chassis216.jpg
 

java

Expedition Leader
Kenny,

I will use the same on the windows, but I prefer some kind of actual sealant on the roof. Piles of snow tent to find any possible entry point as they melt.

Did you use the same type of your roof with no other sealant?

Those are great looking windows too....
 

IdaSHO

IDACAMPER
Kenny,

I will use the same on the windows, but I prefer some kind of actual sealant on the roof. Piles of snow tent to find any possible entry point as they melt.

Did you use the same type of your roof with no other sealant?

Those are great looking windows too....


Ill never own, or build a camper with joints in the roof.

My camper has a mono-shell with zero joints.

It does have a few penetrations, largest being the marine hatch.

By design it is located on a slope of the roof to minimize the potential of leak potential.

Still, it is sealed the same way as the windows. Year later, always outside, north idaho winters, never an issue.


Also, the entire roof is overcoated with Gaco-roof. The one exception being the hatch, all penetrations and fasteners are coated with it.

Gacoroof coat installed

chassis272.jpg


shot showing the location (by design) of the hatch on the slope.

chassis274.jpg


Example of how all fasteners and hardware attached to the roof surface are overcoated.

These are the brackets used to fasten the rigid solar panels.

chassis301.jpg
 

java

Expedition Leader
I forgot you used the Gaco, that's some good stuff. We use it on roof decks all the time.

I have two maxxfans, they are at the center of a curved roof.

Glad to hear the seals work well.
 

javajoe79

Fabricator
That gacoroof looks great! Thanks for the idea. How thick does that go on and how many coats are shown in your pics? How heavy is it once applied and how much did it take to cover your roof?
 

IdaSHO

IDACAMPER
Not sure abotu the actual thickness, its probably at least 20mils.

I've always done two coats, using the specified 100 square feet per gallon per coat as a minimum.

I find "floading" it a bit heavier allows it to build thicker and level better.

So the application on our prototype took about 3 gallons.

It isnt cheap, but IMO it is the best roof coating system available, hand down.
 

IdaSHO

IDACAMPER
I forgot you used the Gaco, that's some good stuff. We use it on roof decks all the time.

I've yet to find a product they make that I dont like.

Years ago I redid our back porch, a solid surface 700+ square foot deck in Gaco-Deck.

Super cool stuff, and nearly 10 years later it still looks new. :victory:
 

javajoe79

Fabricator
Not sure abotu the actual thickness, its probably at least 20mils.

I've always done two coats, using the specified 100 square feet per gallon per coat as a minimum.

I find "floading" it a bit heavier allows it to build thicker and level better.

So the application on our prototype took about 3 gallons.

It isnt cheap, but IMO it is the best roof coating system available, hand down.

I looked up the cost for a 5 gallon bucket and honestly that seems very reasonable for what they claim it provides.
 

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