roof sealants

Vic Harder

Vic Harder

Doctor Electric
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Calgary, Alberta
As I ponder mounting my solar panels and putting holes in the roof of my 2005 Hawk, I started looking for those great threads I have read on this forum, and digging into which sealants to use. I have again found a “simple” question is not that simple, and that the folks who build these campers for us (FWC and ATC) deserve a LOT of credit for making them as affordable and durable as they are.

First, I think we all have aluminum roofs, right? Either one piece (when did that start?) not. This is not the case with other RV’s. This link talks about how to seal most RV roof types - LINK

I already have a solar plug on my roof (it is a ZAMP SAE connector) – and this thread talks about cutting holes and sealing them too.

SIlaprene is apparently what FWC uses - LINK & LINK

Sikaflex is mentioned often too. Turns out that both Silaprene and Sikaflex are product lines, so finding the RIGHT one for our applications is a bit more challenging. Here is the list of the Sikaflex products - LINK

Browsing through this list, I suspect:
Sikaflex 292i – would be good for bonding stuff
Sikaflex 291LOT – would be a good sealant for very wet areas as it can be used below waterline. Might “flow” better too for a nicer look
Sikaflex 291 – good sealant for high vibration areas

Wow, I just found a summary of sealing products for marine use that agrees 100% with what I just said... LINK

And there are lots of other choices. This list is huge... LINK

So, what are you using?

Vic
 
One thing that concerned me is it doesn't mention aluminum in the actual product itself. It is on the manufacturers website though.
I didn't buy it until I checked the site. Even though the guys in the shop said they use it all the time on aluminum.
 
Vic Harder said:
As I ponder mounting my solar panels and putting holes in the roof of my 2005 Hawk, I started looking for those great threads I have read on this forum, and digging into which sealants to use. I have again found a “simple” question is not that simple, and that the folks who build these campers for us (FWC and ATC) deserve a LOT of credit for making them as affordable and durable as they are.

First, I think we all have aluminum roofs, right? Either one piece (when did that start?) not. This is not the case with other RV’s. This link talks about how to seal most RV roof types - LINK

I already have a solar plug on my roof (it is a ZAMP SAE connector) – and this thread talks about cutting holes and sealing them too.

SIlaprene is apparently what FWC uses - LINK & LINK

Sikaflex is mentioned often too. Turns out that both Silaprene and Sikaflex are product lines, so finding the RIGHT one for our applications is a bit more challenging. Here is the list of the Sikaflex products - LINK

Browsing through this list, I suspect:
Sikaflex 292i – would be good for bonding stuff
Sikaflex 291LOT – would be a good sealant for very wet areas as it can be used below waterline. Might “flow” better too for a nicer look
Sikaflex 291 – good sealant for high vibration areas

Wow, I just found a summary of sealing products for marine use that agrees 100% with what I just said... LINK

And there are lots of other choices. This list is huge... LINK

So, what are you using?

Vic
Click to expand...
Vic, check the videos from AM Solar installing panels without drilling holes...

http://amsolar.com/diy-rv-solar-instructions/edmounts/
 
Vic,

Geocel ProFlex RV is what I used on my build. This sealant is very forgiving, when applying. They suggest having some soapy water on hand, and once you've laid a bead with the caulk gun, you dip your finger in the soapy water and press and smooth out the bead until your satisfied.

It gets easier as you go and get the hang of it. In warmer weather, it flattens out more quickly and uniformly, and it seems to shrink down after a few weeks. So a second layer might be in order. Anyhow my 2cents along with Bill D. There are a few photos of applying it on my build thread if you care to look. Good luck!

Poky


Sent from my iPad using Wander The West
 
Wandering Sagebrush said:
Vic, check the videos from AM Solar installing panels without drilling holes...

http://amsolar.com/diy-rv-solar-instructions/edmounts/
Click to expand...
I like the idea of being able to tilt. not sure I would trust that 3m tape. 3m claims 100 lbs tensile strength per sq inch. 4 of those mount might get you 4-8". If the wind gets under there at 70 mph.....

This page is really neat... lots of good info and comparisons - LINK

I think I might want the Sikaflex 291 for general sealant, and 3m 5200 (700psi) to hold down the panels!

I wish my roof was nice a smooth. I see pics of the new shiny one piece roofs and drool!
 
I watched the video on the 3m tape, and I am not sure I would trust it exclusively. I use a lot of 3M tape and pay over $1,000.00 for 24"x60yd roll. The one shown is not even from the 3M automotive division. The surfaces MUST be smooth and flat. There is also an adhesion promoter that will help achieve a 90%+ bond almost instantly.

Vic, There are probably dozens of adhesive/sealants that are more than capable of doing this job. are you sure you aren't over thinking some of this stuff? I do the same....

cwd
 
Vic Harder said:
I wish my roof was nice a smooth. I see pics of the new shiny one piece roofs and drool!
Click to expand...
You'll get hail damage on your roof anyhow.

Sure a one piece roof is nice, but as soon as you add a vent, racks, etc it doesn't make that much of a difference.
By not having a one piece roof perhaps you will be more diligent with your maintenance that others with a one piece may neglect.
 
Just remember the sealants don't last all that long in storage. Don't order until you know you're ready to start the project. Don't ask me how I know this :)
 
I've used 3M 5200 for resealing the water heater, resealing roof screws, resealing roof rack, resealing front roof trim piece, and other stuff. I like it, unless I have to remove it. It works good, durable, available, white. With all the screws on the roof, there's no problem with adding a few more for solar.
 
cwdtmmrs said:
Vic, There are probably dozens of adhesive/sealants that are more than capable of doing this job. are you sure you aren't over thinking some of this stuff? I do the same....

cwd
Click to expand...
Well doh, overthink and plan ad infinitum... yeah, that's me :unsure:
 
AK Nomad said:
I've used 3M 5200 for resealing the water heater, resealing roof screws, resealing roof rack, resealing front roof trim piece, and other stuff. I like it, unless I have to remove it. It works good, durable, available, white. With all the screws on the roof, there's no problem with adding a few more for solar.
Click to expand...
Given how strong this stuff is, I was planning on using it mostly as an adhesive, rather than sealant. Sounds like you use it lots. Have you had any issues with only partially using a tube and then trying to get more out later?
 
Leftovers are nearly impossible to save. If you tape it well you can cut the tube with razor below the hard plug and get a couple more uses


Sent from my iPhone using Wander The West
 
Vic Harder said:
Given how strong this stuff is, I was planning on using it mostly as an adhesive, rather than sealant. Sounds like you use it lots. Have you had any issues with only partially using a tube and then trying to get more out later?
Click to expand...
5200 is commonly used on boats as primarily an adhesive with sealant qualities below the waterline and is considered permanent. Consider 4200 or one of the others mentioned if there is a chance you want to remove it in the future. Just be aware of its properties before selecting it.

Paul
 
Hi Vic - Digging up this old thread as I am researching what I should use on my 2006 Eagle. What did you end up using on your roof? What would you recommend now?
 
mikeyc,


FWIW: All adhesives and sealants are designed with applications in mind around particular materials, temperature ranges, stress loads, etc.

It is worthwhile checking to see that whatever adhesive, sealant or caulk that is recommended and that you consider for use, is intended for the particular application and environment you intend to use it in.

I have used 3M 5200 and 4200, various Sikaflex products (there are many) as well as many others.

In all events make sure that you prep and clean the surfaces in accordance with the manufacturer's instructions for the particular adhesive, sealant or caulk that you use. They are not all the same and some recommend or even require primers (which will have their own application and requirements, such as minimum drying time and maximum time before adhesive is put on it, etc).

Here is a link to a similar thread with more info (I made a comment with links - it is #9)

https://www.wanderthewest.com/forum/topic/21097-adhesive-and-sealants-products-and-applications/?hl=sealants


I hope this is helpful,

Craig
 
+1 to what ckent said.... he seems to know his way around adhesives! I used mostly 4200 on my roof. I save the 5200 for stuff that I hope never comes off. Sikaflex/dicor seems to be more of a sealant than glue, and I will use that too. So, to glue down the screws and housing for the fan, for example, I put 4200 under the plastic bits and in screw holes, put it together and then coat the outside with dicor. It self-levels and looks good doing it.
 
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