Solar panel blown away!

[AIRTRVL]

I’m confused. After reading post by Lewster and others on this forum I have been convinced that the 3M tape that AM Solar provides with their mounts is all that is needed to hold the solar panels to the roof. I just order a solar system from AM Solar and I’m excited to get started with the installation. I’ve asked the Tech’s at AM Solar lots of questions and they have been very helpful. One of the questions that I asked was about using just the 3M Tape for mounting the panels. The answer I got surprised me. I was told that some people use just the tape but at AM Solar they don’t for liability reasons. If the people at AM Solar use screws or rivets along with the 3M tape for liability reasons they must believe that there is a possibility that the tape alone could give way. Now I don’t know what I should do. Any thoughts? I hope Lewster could give some insight as to why AM Solar is not using just the tape.

[ghaynes755]

Did they say they were using screw/rivets on an Airstream? Or was there a translation issue? If you asked if they just used tape and the answer was no then that is correct but doesn't mean screws/rivets. They cover the panel base with Dicor or Sikaflex to keep out water which can freeze.

I looked at a recent question I had with Lew and he said to use Sikaflex 221 and clean the surface and mounting plate with brake/carb cleaner on a rag before putting on the tape. I think the kit that comes from AMSolar has the VHB already mounted to the feet.

[J. Morgan]

Just my experience, two sided tape is great stuff, but depending on temperature at application and a few days thereafter, and whether the surface is truly clean, it does not ALWAYS stick really well.

For liability reasons relating to DIY installers etc, the manufacturer is going to recommend tape plus screws or rivets.

Additionally, two sided tape is only as secure as the surface it is applied to. In other words, if it is stuck to a painted or otherwise coated roof, and the paint or coating is not stuck to the surface really well, the tape can fail while working perfectly.

I would think that factory paint would seldom if ever be a problem, other coatings and the applications of these coatings are going to be questionable.


1/2 Ton 4WD Truck, 72 Sovereign Hensley Arrow

[TinTin]

Originally Posted by AIRTRVL

I’m confused. After reading post by Lewster and others on this forum I have been convinced that the 3M tape that AM Solar provides with their mounts is all that is needed to hold the solar panels to the roof. I just order a solar system from AM Solar and I’m excited to get started with the installation. I’ve asked the Tech’s at AM Solar lots of questions and they have been very helpful. One of the questions that I asked was about using just the 3M Tape for mounting the panels. The answer I got surprised me. I was told that some people use just the tape but at AM Solar they don’t for liability reasons. If the people at AM Solar use screws or rivets along with the 3M tape for liability reasons they must believe that there is a possibility that the tape alone could give way. Now I don’t know what I should do. Any thoughts? I hope Lewster could give some insight as to why AM Solar is not using just the tape.

I got the same response when I called in my order to AM Solar. They suggested tape, screws, and Dicor which we ended up using. My local installer was also not happy with tape. That said, Lew probably has more experience than anyone in this field.

[AIRTRVL]

I called AM Solar back today and asked how they install the mounts to the AS. They clean the roof with alcohol install the mount with 3M tape and install #10 by 1” screws. Then they seal the edge of the 3M tape and screws with nonleveling Dicor.

[lewster]

Here is the 'skinny' on how I mount the panels. The factory and I differ a bit, as they use Dicor self-leveling sealant in the feet. I prefer SikaFlex 221 as is is not only a sealant, but also a super adhesive/bonding agent.

In fact, if I didn't need the immediate bond from the VHB tape, I would use 100% SikaFlex.

I also do custom shaping and angling of the panel feet as required to obtain the largest contact area possible.

Airstream uses SikaFlex 221 to bond the crank-up antenna to the roof. The screws simply hold it in place while the SikaFlex bonds and cures.

I discovered this years ago when trying to remove an antenna base. It literally has to be cut off, as the adhesive power of the SikaFlex bond could NOT bd broken!

In summary, I depend on the SikaFlex bond to supplement the VHB tape and double or triple the bond strength of the VHB.

And BTW, my old Sprinter service van had 4 panels on the roof with no sealant..........just the VHB. None of the feet loosened after 7 years! When I recently removed the 5 panels from my '11 Sprinter to test the Flex panels, it took half a day to get the feet and VHB residue off the roof.

To reiterate, I have NEVER LOST A PANEL in 10 years of installing solar, and I have never used a screw on an Airstream roof!

YMMV! :-)




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

[rmkrum]

Lewster,

Didn't you mention that alcohol was not the right stuff to clean with before using the tape?


Sent from my pocket Internet using Airstream Forums

[lewster]

Originally Posted by rmkrum

Lewster,

Didn't you mention that alcohol was not the right stuff to clean with before using the tape?


Sent from my pocket Internet using Airstream Forums

Alcohol is OK for cleaning the roof substrate for the VHB prep and Dicor, but is a very bad choice when using ANY polyurethane sealants like SikaFlex 221, as it inhibits the bonding strength and cure rate (this is direct from Sika tech support).

Any acetone based cleaner or pure acetone will not contaminate the roof substrate when using polyurethane sealants. Just be sure to wear nitrile or similar gloves when using acetone, as it absorbs very quickly into the skin and can cause long term liver and kidney damage.

[AIRTRVL]

Thanks for all the great information. It’s always best to ask the experts before taking on a project like this. I’m going to take Lewster’s advice and avoid drilling holes. Thanks again

[johnkellygre]

Originally Posted by lewster

It certainly IS strong, but there IS a way to get the stuff off cleanly! PM me if you are in need of this proprietary information.

Hello Lewster, Regarding your proprietary method for VHB tape removal, I could really use some advice. I made custom aluminum brackets to fix my 2 160 watt panels to the roof of my 1985 Sovereign. They have been cooking in the sun since spring. Two of the bracket feet popped when I checked by pulling them up with a bit of pressure (25#'s.) I used VHB Adhesive Tape 5952 and installed them according to your recommendations (as far as I know.) Did I use the correct VHB tape? Could you send me the tape removal method you use? Thanks very much. I'm sure I did something wrong during the installation.

[carl2591]

Originally Posted by lewster

Allow me to present a different scenario…………

After literally thousands of installations of RV solar charging systems, AM Solar has NEVER LOST A PANEL!!!!!!!!! This includes both the screw-down installations on textured and or rubber roofing substrates AND the bonded installations for metal roofs (like Airstreams) and smooth fiberglass roofing found on large motorhomes.

I have been installing systems for AM Solar for 8 years and have never had a panel loosen, let alone be blown completely off the roof.

I think your dealer and their techs have quite a bit to learn about the proper technique of installing solar panels on RV roofs in general, and Airstreams in particular!!!

I have yet to use a single screw in any of my Airstream installations, and rarely even penetrate the roof at all! 3M VHB tape is a very powerful bonding agent used primarily in the automotive industry to attach body parts like roofs and other panels. It has an extremely high shear strength which makes it perfect for bonding solar panels too the proper RV roofing substrates. Proper cleaning and surface preparation is essential to assure a complete bond with the use of VHB tape

This is followed in my installations by an application of SikaFlex 221 as both a second bonding agent and a waterproofing seal to prevent moisture from potentially attacking the VHB bond.

I think it would be of great benefit to both you and your Airstream to find a better qualified installer for your solar panels…..one who will not simply put more unnecessary holes in your roof !!!!!

FOLKS read this part again. and if you think you are doing good by putting screws in, read it AGAIN..

thanks Lew... good advise

[lewster]

Originally Posted by carl2591

FOLKS read this part again. and if you think you are doing good by putting screws in, read it AGAIN..

thanks Lew... good advise

Any Time!

[Bexar]

Originally Posted by J. Morgan

Two words... Rivet nuts.

http://www.fastenersuperstore.com/nu...ded-Inserts%29

Tnx! This a great solution to create a rock solid mount.