A lot of folks are using VHB tape to attach various things to their Fiberglass campers. I posted this to another thread, but figured it might get buried, so here it is:
re: 3m VHB tape for solar
panels, and awnings
3m's support has been excellent. We were at the annual trade show for our hardware store supplier in Orlando in late Feb. 2015. I had some questions about mounting a solar panel
with VHB tape. There was a member of the technical department at the 3m booth. He answered nearly all my questions and while I waited, he called another tech person at 3m when he did not have an answer to one of the questions.
That question was about surface preparation of fiberglass before applying VHB tape. The "VHB Tape" specialist on the phone call from the office recommended using Acetone to clean the fiberglass gelcoat, then clean off the Acetone residue with alcohol, (even though Acetone evaporates quickly, it does leave a very light
residue) and then a light
scuffing using a Scotch Brite type pad or very light
touch with very fine sandpaper before applying the VHB tape. He said Not to use MEK as a cleaner or prep, as that might soften the Fiberglass.
The tech rep. at the show also mentioned the fact that you should wait at least 24 hours, and preferably more, before putting full weight
on the item. He noted that one big reason VHB tape was developed was to hold Automotive Side Molding on to Cars and Trucks, and that in the past, 3m sold more VHB tape to Auto manufacturers than to anyone else. He also said that Scotch, "Extreme Mounting Tape" #414, sold at many hardware stores, is consumer packaging of VHB tape. That product is advertised to hold 20# for a 40" strip, or 1/2# per square inch. There is another Scotch 3m product that says it will hold 10#per 40" strip, but that is not true VHB tape. #414 is 1"x60", and sells for around $7-10, but appears about .025 thick--and most folks have been using the .045 thick VHB tape for most purposes on our FGRV's. So, if you can use the thinner version of VHB, it's available on the shelf at many Hardware Stores.
And, most all sizes and thicknesses are available through Grainger, but almost always require a 2 day wait. That was the case when I ordered some VHB tape to install bendable solar
panels on our Eggcamper
. Grainger ordered it from a regional warehouse and I picked it up at the local branch store in 2 days. Still haven't installed the panels yet, but hope to soon. Maybe I'll install an awning
with VHB also.