Community Forums

txatollman · 03-09-2020, 12:06 PM

I've searched the forum for information about adhesives, and none of the threads really match my purpose...

I have a class A with a TPO roof, and I want to mount a kayak rack without drilling holes. There was a old tread on that subject but the advice was inconclusive. Someone mentioned using 3M™ Marine Adhesive Sealant 5200 to mount solar panels on a roof, but it wasn't clear if the roof was TPO. Solar panels would have a bigger bonding surface than typical kayak rack 'feet', but it does hint at feasibility.

I can mount the rack's 'feet' to metal or thick plastic plates to increase the bonding surface area between the roof and the rack.

Besides the 5200 sealant someone mentioned for the solar panels, my research indicated 3M™ Scotch-Weld™ Structural Plastic Adhesive DP8010 is good for TPO.

Has anyone mounted anything to a TPO roof with adhesive, where shear strength was a consideration?

Thanks in advance.

Meames1 · 03-09-2020, 01:12 PM

I would be concerned with the TPO-RV shear strength. Are you going to tie down the kayaks strictly to the rack or to the RV somehow? When I built my rack I used clamp brackets into the drip rail and bolted the rack to them. I also thought about adhesive directly to my roof (fiberglass) but I became uncertain without any mechanical attachment what might happen. Sorry, that doesn't answer your adhesive question though...

Gary RVRoamer · 03-10-2020, 08:26 AM

This article on bonding to TPO should help:

http://www.buypmc.com/wp-content/upl...ding-Guide.pdf

https://multimedia.3m.com/mws/media/...-solutions.pdf

I saw a recommendation for 3M VHB tape elsewhere, but not sure if it was based on real life experience with TPO or just cause it's a generally terrific product with lots of uses.

Personally, I'd put holes in the roof. No worries at all if you do a competent job of sealing the screw heads.

Hooligan · 03-10-2020, 08:50 AM

TPO is a rubber (ThermoPlastic) roof fabric that is glued to a substrate, usually plywood... No matter how firmly your mounts are bonded to the TPO, it is still subject to pulling away from the underlayment. A mechanical attachment, holes/bolts would be a better solution.
TPO or rubber roofs often develop bubbles from the fabric detaching from the plywood. Chemicals in the adhesive you use could actually cause the fabric to release from the plywood.

Bill Gail · 03-10-2020, 11:33 AM

There are other options . Have you seen the kayak racks that go in the receiver hitch and store the kayaks vertically on the rear of the MH ? They will work with the 10' kayaks , anything longer will need to be stored horizontal.

153stars · 03-11-2020, 08:22 AM

Loading and unloading forces,the amount of load it would take to just secure a Kayak. Plus wind at 65 mph, low hanging trees,puts it apart from a solar panel mounting. Just think of what would happen if your membrane would lift and tear off. I wouldn't want a kayak to go flying back off toward someone or me in an event like that. If I put mounts on roof they would have large strong stainless or alum. base for pad and tie downs all on one. With enough width to load straps well and only need a least amount fasteners into roof member if possible.
I would look for an alternative, on toad roof, inflatable kayak.