VanDweller Community Forums

Full Version: 3M VHB Tape review
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Pages: 1 2 3
I was going to use 3M VHB Tape alone to hold my solar panel on the roof after watching a lot of good reviews on YouTube about the tape.  But after testing the strength of the tape, I changed my mind.

I did however use it in combination with the self drilling screws to secure the panel to the roof.  Although I can confirm the tape is strong, it's not quite strong enough to confidently use the tape alone to secure solar panels onto roofs.  

In a very unscientific, rough experiment to test the strength of the tape;  I taped two brackets together and tried to pull these apart using only my hands.  This is the result:

3M tape on a bracket: https://imgur.com/a/T0nKUID

Two brackets taped together before stress test: https://imgur.com/a/Cs8YFUj

The two brackets after stress test: https://imgur.com/a/2233oOd

Conclusion: It's okay to use 3M VHB tape to secure solar panels to roofs, but only in combination with screws or bolts.
(09-14-2019, 11:08 PM)poot_traveller Wrote: [ -> ]Conclusion: It's okay to use 3M VHB tape to secure solar panels to roofs, but only in combination with screws or bolts.

funny, that is pretty much what the manufacture said....

imagine that
(09-14-2019, 11:19 PM)Seminole Wind Wrote: [ -> ]funny, that is pretty much what the manufacture said....

imagine that

And several members here also.


BTW, where you been?
(09-15-2019, 05:06 AM)LoupGarou Wrote: [ -> ]Keep in mind there’s many grades of VHB tape available.

https://www.3m.com/3M/en_US/company-us/all-3m-products/~/All-3M-Products/Adhesives-Tapes/VHB/3M-VHB-Tapes/?N=5002385+8710676+8711017+8711740+8713604+3294857497&rt=r3

Well of course there is different grades and I'm only finding that out now. It's like the fuse holders, nobody says nothing until I buy the fuse holders, then it's; "sorry to tell you this but the wires are too thin on the fuse holders, you've got to buy fuse holders with thicker wire."
(09-14-2019, 11:19 PM)Seminole Wind Wrote: [ -> ]funny, that is pretty much what the manufacture said....

imagine that

Yes, and I am able to confirm what they are saying is correct.
(09-15-2019, 08:20 AM)tx2sturgis Wrote: [ -> ]And several members here also.

Exactly seven member huh? Not six, not eight. But several members.
Yes, elevendy seven point two niney eight.

Cool
(09-14-2019, 11:08 PM)poot_traveller Wrote: [ -> ]I was going to use 3M VHB Tape alone to hold my solar panel on the roof after watching a lot of good reviews on YouTube about the tape.  But after testing the strength of the tape, I changed my mind.

I did however use it in combination with the self drilling screws to secure the panel to the roof.  Although I can confirm the tape is strong, it's not quite strong enough to confidently use the tape alone to secure solar panels onto roofs.  

In a very unscientific, rough experiment to test the strength of the tape;  I taped two brackets together and tried to pull these apart using only my hands.  This is the result:

3M tape on a bracket: https://imgur.com/a/T0nKUID

Two brackets taped together before stress test: https://imgur.com/a/Cs8YFUj

The two brackets after stress test: https://imgur.com/a/2233oOd

Conclusion: It's okay to use 3M VHB tape to secure solar panels to roofs, but only in combination with screws or bolts.
I am guessing you did not realize that there are 7 different "families" of 3M VHB tape. Each family has particular characteristics which make it more suitable for various applications. For instance some bond better to painted surfaces and some bond better to plastic or aluminum and some can be used in higher temperature applications. 3M VHB is a broad category and if you got the wrong family of tape for your needs then you could very well have a failure in your application. Not only that but sometimes you need to purchase one of the specialized adhesive bonding promoters that need to be brushed onto the surfaces before the tape is applied.

We all know that surface prep has to be done according to the instructions. If you don't do it correctly you can have adhesive failure. The adhesive that fails might be the VHB or it might be the paint adhesion on the van which has failed.

Part of choosing the right tape is doing the background research on the 3M website to find out which family of tape is best suited to your needs. Then of course doing the prep work which might include applying an appropriate bonding promoter. Another factor which is essential in deciding if you will be able to use VHB tape is the amount of surface area on the brackets themselves. The VHB tape is rated for strength based on the number of square inches of surface. So each bracket must meet the specifications for the load ratings that are stated for each of the different families of 3M VHB tape. That means you must do some engineering calculations based on your own unique applications of the tape and also the size of the brackets as well as the wind speeds and resulting forces of pounds of pull on your panels. Another major issue with using VHB tape on vans is many of the vans have paint that peels easily and gets damaged by the UV rays. The paint adhesion will fail and since the VHB tape is stuck to the paint the problem is not a tape adhesion failure it is a paint adhesion failure. I would say that on any of the older vans you either need to repaint the area where the brackets will be installed and then give the paint several weeks time to cure or else just go ahead and use mechanical fasteners to install the brackets.
By the way....VHB tape develops strength over time. Trying to figure out if it is strong enough by immediately pulling on it after you apply will never be an accurate test of its true strength as it has not had sufficient time to develop its full strength.

I don't know of any adhesives that have full strength immediately after application. I use a lot of various adhesives and they all state a full cure time rating of a week or more. Some of course will give you a shorter time for more immediate use but if you read carefully the length of time for a full cure is longer than that.

Because I have a work background in manufacturing I have to read directions very carefully so I know how to apply the adhesive, what it is rated for and how long it takes to develop strength. Some persons will do that when they work with adhesives but others just read the front of the package and then go for it. But when you have hundreds of dollars invested in something such as solar panels and when it is a critical safety issue that the stay put when you are out on the road you need to take the time to truly understand what is going to give you the results you need to have.

I have a painted roof on my trailer, it is good paint but I don't trust it not to have localized failure so I won't be using VHB tape on its own for the installation. I also have a fiberglass roof so on the interior I will install blocking and then thru bolt my solar panel brackets to secure them. Screws thru just the fiberglass would not give adequate strength, the fiberglass is not thick enough for screw holding under the load forces that will be put on the panels when underway on the road.
Pages: 1 2 3