Is 3M Very High Bond Tape strong enough to secure a solar panel on an RV?
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- čas přidán 27. 08. 2024
- I hate drilling holes in my camper. Other videos talk about using Very High Bond double sided tape like 3M VHB 5952. This video covers my take on 3M strength data, an estimate of the wind load on a panel on top of my camper, and my own "poor man's" strength tests. I concluded that this tape is 12 to 24 times stronger than the wind load acting on the panel if I use six 2-inch taped brackets to hold the panel. But a safety attachment point is a good idea if you can find one without drilling and if you are still nervous, like me.
I also cover the surface prep procedures that you should follow to assure this kind of performance.
CAUTION: I do not recommend VHB tape on rubber-coated or rolled-on roofs. I believe the turbulent pulsations would weaken that kind of roofing and rip it off at high speed.
Materials used in the surface prep include:
3M VHB Tape
220 grit sand paper
Isopropyl Alcohol, 70%
I am no longer an Amazon Affiliate but if you search on the words you should find it.
I cover my own do-drill, low-cost, DIY solar panel install on my Four Wheel Camper in a companion video here: • No-Drill, Low-cost, DI...
I used 3M DS tape to secure my panels on my Ford E150 Explorer custom camper van . I did the job over two years ago. My panels sit on aluminum adjustable rails I built. They are every bit as strong today as they were the day I put them on. If you leave the van or rv in direct sun every day it may not be as safe and durable. My van does sit mostly at night under a carport ... But does sit in sun most days
And when that panel comes loose at speed and injures or kills someone you can explain to the judge in court how you felt TAPE was good enough.
I think solar panels screwed to the roof is worth the peace of mind. Great video on the tape. I learned something today!
Thanks for the comment @henrymorgan3982! Peace of mind goes both ways, I also worry about moisture seeping in through holes in my camper! But your comment is well taken and I agree that everyone should add as much attachment as needed to bring them peace of mind. For me, it is a few strong metal attachment points in addition to the tape.
I really recommend at least one leash or strong attachment. But there are many people using VHB tape alone and as one vendor who uses it has said, "I've never heard of anyone losing a panel"
I once forgot a temporary rigid panel laying on my roof with no tape and it didn't go flying until we hit 60 mph so that informs some of my peace of mind--the 10 - 15 lbs from gravity holding the panel down by itself was enough until nearly full freeway speed, so VHB tape along with supplemental safety attachment is fine for me, and VHB alone is fine for a lot of people. The airborne panel did not hit anyone, thankfully! Thanks again for your thoughts!
Put a wind deflector in front of the solar panels. This will stop wind sheer. Use the VHB tape on the wind deflector. PERFECT
I like the idea. That should eliminate any shear forces. Thanks.
My solar panels (which died last week) have been on the roof of my van for about eight years with 110,000 cross-country miles driven. 3M VHB tape holds the solar panels to the roof. A layer of mastic tape is on top of the bracket feet, also covering the VBH tape. No problems ever. No loosening of the tape. The solar panels are mounted using Z brackets which have a low clearance of only 1" above the roof top.
Now, I have to get all that tape off my no-hole roof so I can put on new solar panels! ... using the same tape method I just described.
Wow, 8 years and 110,000 miles is the longest testament to VHB durability that I have seen! Thanks for contributing that. We are only at 5 years so far. Good luck on removal. From videos I've viewed and a test bracket I removed: heat gun, hand scraper and clean final residue off with paint thinner or similar hydrocarbon solvent. Definitely a chore, but doable. Thanks.
OMG, thanks for taking the time to make this video.I want to install solar panels on my TT, and I really don't want to put any holes in the roof. I am planning to use VHB tape and eternabond tape as an additional layer of protection.
Thanks! Good luck on your install. I'm getting close to 5 years and still looks good.
Great information & thank you for sharing all your research, I've always thought about trying something like that but didn't want to take a chance of it not working. In the past I have installed ladder/cargo racks & have had some end up making a lot of wind noise.
Been using this tape on my rooftop tent solar panels and it's holding up great. Probably had over 10k miles on it so far, year later.
Good to hear! We have about 60k miles so far including many days over 100F and well below freezing, and the brackets still appear fine. Thanks for your comment.
This definitely calms my fears of using vhb for my panels. I have an aluminum roof and plan on securing my panels with 90° aluminum trim equal to their length using vhb tape.
It's overkill, and now I know for sure it'll work.
Thanks for the comment @fuqinazhole. Yes, I agree, 90" of VHB should be overkill! Not sure of your configuration, but I left a little space under my panel to allow a little cooling air flow on the bottom of the panel as they say cooler panels are more efficient. How much more, I don't know. And a lot of people attach non-rigid panels directly on the roof surface, so maybe its not a big deal.
@@sagebrushers8497 my plan was to vhb the length of the 90° bits to the roof and bolt the panel onto the vertical face, leaving 1-2" space underneath. I guess I could use vhb for that whole process, idk. Might not be cost effective, tho.
thanks for doing this research. I,ll be adding panels this fall
Great testing and analysis!
My impression is some RVs have some kind of rolled roofing on them. In such a case it seems that using sticky stuff to attach solar panels might increase the risk of loss of the roofing material itself.
Yes, I think you are right. Really should have a hard and very smooth surface, like painted metal or fiberglass.
I have epdm rubber painted in Dicor rubber roof coating. Any suggestions. I was thinking SOME screws at front and rely on tape for the rest? Yes/no?? Great video BTW!!
@@franknabuurs3401 Thanks for your comment! Clearly some screws on the front edge would help to keep the panel attached, but my fear would be that the pulsating turbulence would eventually cause the trailing edge to pull up the rubber roof coating, or the VHB tape on that edge. If it did that, it would damage your roof coating and could ultimately cause the screws on the front edge could work out.
This is fantastic testing and info, thank you!
Thanks much!
I solute you as a fellow engineer but I woukd have done the sheer calculations in conjunction with environmental testing. I'm comfortable enough to just use tbe tape based on your analytics. Saved me a ton of time. Thank you very much
Thank you @curve5746. I would have done sheer calculations but I'm not that kind of engineer and my mechanical engineer son was to busy to bother. ;-) Glad is was helpful.
Thanks! Useful information indeed.
Wow, very informative. Thank you.
Glad is was helpful. Thanks much for the comment!
So in a nutshell, for those of us that have our RV’s permanently setup at the lake, this application should work without much fuss.
Yes, as long as you have a sealant to keep moisture out, it should last a long time.
I really appreciate all the thought, calculation and testing you put into this topic.
My only question though, is why not just use a rail that runs the length of the supported sides instead of the six little 2" feet? That gives you ten times (loosely estimating) the adhesion area of the little brackets, and also spreads the load out across the roof instead of concentrating it on the fiberglass laminate just at those six points.
Just a thought to toss out there for ya.
Enjoyed the video... it did answer a lot of questions for me, and I feel better about proceeding with the VHB idea than I did before. (I'll be doing rails though... much bigger panels too)
Good question, @1SqueakyWheel! To be honest, I saw vendor kits that used 4 or 6 small brackets and didn't think about it. I just mimicked them. I think you have a great idea, especially if you want to get even more taped area (and more peace of mind) at minimal cost.
My only hesitation in doing that would be restricting airflow too much under the panel, because hot panels are less efficient, but that can be mitigated by making sure there is a decent air space underneath the panel, say 1 to 2 inches? An aluminum angle (or square tube or channel with say 1 inch on the bottom side and 2 inches sticking up might do it. You could even lighten it and ventilate better with large holes along the length of it. But that might be too much work. Just thinking...
I would still lap-seal or Eternabond both sides and ends of the track or angle pieces to prevent moisture from getting to the VHB tape. I'm no expert, but that's what I'm thinking.
I used 3M VHB Heavy Duty Mounting Tape 4950 for years... Once applied. You need a crowbar to get it off....I sealed around it with 3M windshield adhesive. As it stays put just like your windshield. Water tight. That thing is not coming off..
Just clean and prep the surface real good. Make sure you get below any painted gel coat surface. Unless you know for sure the clear coat is bonded to the paint and not peeling...As this is where the bond will break off at..the paint gives out...Thus losing the bond...
Good job. 👍🏻
According to 3M instructions, you have to wait a certain amount of hours before applying any force to the item glued to get the maximum strength of the bonding:
"After application, the bond strength will increase as the adhesive flows onto the surface. At room temperature, approximately 50% of the ultimate strength will be achieved after 20 minutes, 90% after 24 hours and 100% after 72 hours".
That is exactly right Charlevoix418. The 3M data sheet also adds that bonding "is faster at higher temperatures
and slower at lower temperatures." Now that winter is here, I would not apply the 3m VHB tapes on a cold day unless you can let your rig sit in a warm garage for 1 - 3 days. It just will not bond properly on cold days. People should find the 3M Technical Data Sheet for more detail on this. Thanks for that comment!
Well done and appreciated from up in Canada.
Thanks Ghostflight73. We are in Canada and loving it! Just don't use on rolled-on roof coatings, as mentioned before.
Nope, jayco full fiberglass one piece roof. Should be fine. Cheers
Great video demonstration and evaluation. My feeling is 8 brackets for the super worried world be an alternative for the leash bracket.
I'm trying to find a preferably pre made flush spoiler to help with wound load deflection. Very helpful.
Thanks @sladestone1197. Let us know if you find a spoiler for wind deflection!
In April 2022 I installed my flexible solar panels using vhb tape. It is now June 2023 and there is zero signs of it failing. I doubt it will ever come off.
Good to hear @clintonkirker5154! Just wondering if you can still seal the vhb tape with a sealant or if you rely on it being underneath the panel to minimize degradation by moisture?
@@sagebrushers8497 I put the vhb tape all the way around the edge of the panels and several more pieces under the panels, probably overkill, but it has yet to give me any cause for concern.
@clintonkirker5154 yeah, sounds pretty secure. You should be able to spot any degradation from the elements long before it became a problem.
What type roof can I ask…mine is a walk on type 2021 rockwood mini lite 22’
@@davidsvoboda7307 fiberglass
I have been considering to do the same. My problem is that on a RV roof you are NOT attaching the bracket to a solid metal surface, but to an EPDM or TPO plastic film. So all the load will transfer directly to the roof cover and THAT is not sure will stand…
You are correct. You should never use this VHB method with an EPDM surface or any kind of rolled on film. Only use it with hard, smooth surfaces! Mine is painted aluminum.
Thanks! My van has no rails and I want to put a flexible panel on it. This is very helpful.
Good to hear! Note, a flexible panel is even thinner and also closer to the surface so the wind forces should be even less. Just make sure the back of the panel is very smooth to assure good adhesion (I assume it is but I don't have experience with them). Thanks for your comment!
@@sagebrushers8497 I've watched a few videos now and it seems the best way is to use a plastic cardboard or similar backing. It was suggested to me a while ago that glue or tape could work, but I was skeptical. Your research and explanation gives me confidence it will work.
Im gonna try this on my boat dashboard with an abs board stuck to my boat dash with this tape.
Should work great as long as both surfaces are hard and smooth, and protected from the environment with a sealant of some kind like Dichor lap sealant or Eternabond or something like that. Good luck!
It would be a good idea when there is no rain. Rain cut the double side tape and silicone like a knife when one is driving on a freeway during the rain.
The tape is under the bracket and well protected from rain. It has upheld in rain storms on the freeway numerous times in the last 5 years and has held well. Thanks for watching.
I've had 8 panels on the roof of my rv for a couple years using this method. I also used eternabond roof tape over top of the bracket onto the roof. It's rock solid.
@@briang7870 Have you see how water cut the rocks and metal under the pressure?
When you are driving your RV on the freeway during the rain try to stick out your hand out of the window (for short time) to understand the force of the rain.
@paveloleynik2743 I guess it would be peeling all the silicon around my windows and roof vents off too. I get what your saying but that's a pretty far stretch. There's no signs of the rain cutting into anything.
@@briang7870 ok
What always gets left out of these conversations is the heat/cool cycle that usually impacts adhesives in a dramatic way. what if exposed to 100f for 8 hours during the day and then 35f for 8 hours at night? ... a very likely scenario if traveling in the southwest. That cycle plays havoc on materials.
You have a good point @thomasfeiller2207. My thoughts (I'm not a materials expert) are 1) the 3m VHB temperature rating is -35C (-31F) to 90C (194F) but that doesn't totally address temperature cycling issue you raise; 2) Such cycling is most damaging IMHO when moisture is present causing damaging freeze-thaw action, hence the importance of a lap sealant to isolate the VHB tape from moisture; and 3) Our solar panel installation on our camper is approaching a 5 year life. Our camper resides outside in the inland west with days over 100F and below 20F and we have travelled from Baja to the Arctic Ocean, especially desert country, and I see no degradation, visually. Time will tell. I will maybe do a pull up test on the panel at the 5 year mark.
Thanks for the thoughtful comment.
Thanks for the response. I don't think we can argue with 5 years of success. It could be, however, that at some point a threshold is reached where a breakdown of the adhesive begins... 6 years? 10 years? who knows. But 5 years is a pretty good testimony to the quality of the product and process.@@sagebrushers8497
The engineer in me says this is a faulty analysis in that you are only accounting for shear strength and have forgotten that at 100mph there will also be a "lift and suck" value from the wind going underneath and over the flat panel, which will try to rip off or pull upwards. Think of an airfoil or airplane wing and how it creates lift based on the venturi effect . So you have horizontal shear and vertical rip-off shear to worry about. Not sure what exact numbers are for vertical lift-off shear but both combined would result in a sort of peel off strength. If it were me, I would add an air deflector in front of panel to deflect air from getting underneath panel and/or raise the trailing edge by lets say 3/4 inch so the wind going over the panel would be pushing the panel down all the time thus leaving you with only having to worry about horizontal shear strength. Does this make sense?
Thanks for the comment @kwiknuts1! Your discussion does make sense, especially for installations closer to the front edge or on a rounded front of an RV roof. And I think you have a great idea for the air deflector in front of the panel to keep air from flowing under it.
I considered the tensile and peel back forces that you mention, but felt they were less important, particularly for my setup set back in the middle of the roof in the turbulent cavity. Note in my table at 1:34 in the video, I provide 3M data for their dynamic adhesion tests including a "90 degree peel" test and a "normal tensile" test. Dynamic adhesion are quick tests that would represent more of a gust of wind so they are fairly relevant for the vertical force on the panel. These data show the VHB tape is much stronger for these vertical forces than shear forces and that is why I tended to ignore them in the video. And I still feel that the shear forces are greater than the force of lift, but like you, I'm not sure what the exact numbers would be. Hmm, maybe another test?
In any event, we have 60,000 miles in 4 years and the panel brackets with VHB tape and Dicor lap sealant look rock solid so that is reassuring. And, if you watched my previous video you will see that the engineer in me caused me to put 4 metal tie-points on the panel just to be sure! If I were to do it again, I'd probably put a little deflector in front and skip the metal ties. Or most of them anyway.
I ised a sealant called solar seal. Set up like a rubber thar holds better that super glue. I don't think I could get it off if I wanted to
The thing I hate is that it's super expensive :(
The load needs to be pressing slightly down when in motion never should they be tilted even slightly at a lift angle...
Good comment. A lifting angle could happen at the front edge of a rounded roof, so people should be aware of that!
I’ve been wondering about the surfaces on van roofs and some rv,s. The roof is painted and probably has a clear coat. Don’t know if the clear coat would peel with all of the wind load.
My thoughts are that any true "paint" like enamel or factory-painted automotive paint that is strongly adhered will be fine. It is just the thicker elastomeric coatings or rolled on roofing sealants that could peel off that are not compatible with very high bond tapes. If you could scrape it off with a hand scraper--it is not a good surface for VHB tape. Just my opinion.
Great video. Thanks! How are your panels holding up eight months later?
Thanks for the comment @teering. Actually the panel has been installed almost 4 years now and there is no sign of degradation or loosening. Feels rock solid. One bracket screw is missing and needs replacing, but that is a different issue. Our camper sits outside on many days over 100F every summer and in freezing conditions in the winter, although I cover it for the worst 3 months of winter.
Updates? Please
Well, I will just say that after 4 years and 11 months and about 76,000 miles, my VHB tape-attached solar panel is still up there. I plan to do a stress test at the 5 year anniversary of my solar install in late May/early June of this year and will post a more complete update then. Hopefully I won't rip them off by pulling too hard! Stay tuned! And thanks for the question.
We are going to use eternabond tape to hold it down.
I am not familiar with Eternabond tape but it seems to be very popular for sealing RV roofs and for sealing solar panel brackets. Are you using a two-sided Eternabond under the brackets or panels or a single-sided Eternabond product over the top of them? I ask because it seems like the single-sided Eternabond is great for sealing, but I'm not so sure it is as strong an attachment like a two-sided VHB tape (3M or Eternabond). Like I said, I have no experience with it but if it were me, I'd put a two-sided tape under your bracket for strength then a one-sided tape to seal it from the environment. I think Eternabond also offers two-sided tapes similar to 3M VHB and probably just as good.
When I see Eternabond tape over a bracket, I worry about the inside edge of the bracket where the vertical side meets the roof and is usually not sealed. That would be my hesitation with using a one-sided tape over the bracket along 3 edges to seal it from moisture.
Those are just my thoughts. My tests show really very little wind force on the panels if they are not set near the front edge of the roof, so you will probably be ok if the Eternabond is as tough as it appears in the videos I've seen. But, If I used it, I think I'd still use a two-sided tape under the brackets, just to be sure. The number and length of brackets makes a difference too.
Good luck with your install!
@@sagebrushers8497 we put Manus-Bond 75-Am under the brackets on the roof and then we used eternabbond tape on top of the brackets. We are going to see if it’s going to hold good. If not we will just put screws on it.
@@sagebrushers8497 Eternabond tape is pretty tough. We had to use it on the edge of our rv roof. It was very sticky and hard to come off.
@@sagebrushers8497 we are using the single sided one. I don’t know if they have any with the double sided ones.
@@jessicamathews5758 Thanks for the info. I looked at Manus Bond 75am online and it seems to be good stuff with strong adhesion to metals, painted surfaces etc. I would guess that with Eternabond covering it is plenty strong. Please let us know how it works! And thanks for sharing your approach.
Hmm.. most roofs get pretty hot and from my own experience tape dont holdup well to heat. One way to remove adhesive is to apply heat, so u know where im going with this. For lightweight flexible panels mayb but i personaly wouldnt trust tape to hold down aluminum framed panels. Id hate to see that panel ripped off someones rv n heading towards me going at 80 mph. But atleast u have the simpson strong tie as a backup. Please nobody rely on tape alone to holdown the hard metal solar panels without any type of backup.
You have a very good point @theinnocent32. I agree many tapes don't hold up well to heat. However, you inspired me to check it out. I waited for a 107 degree F day, then put a digital meat thermometer with the tip pressed into the dicor sealant at the edge of the aluminum bracket (closest to the VHB tape as I could get. It was very sunny but I shaded it with reflectix for the10 seconds it took to get a stable reading. I got up to 124F at that point.
Next I looked at the 3m Data Sheet for the 5952 VHB tape I used , found (accessed 7/22/2023 at technicaldatasheets.3m.com/en_US?pif=000083) and found this:
"Short term temperature resistance at 149C/300F: no change in room temperature dynamic shear properties following 4 hour conditioning at indicated temperature"
In fact they say when applying this tape you get the strongest bond at 150F! Amazing stuff. I still think it is a good idea to have a metal fastening point or leash. And never apply to a rolled on roofing material-- just hard, smooth surfaces that can't peel off.
Thanks much for your excellent question.
👍
Hell no. 1 day in Wyoming that will fly off
For rolled on roofing on big RVs, you may be right, @SolarPowerMyRV. But our 60,000 miles, some at 80mph with 20mph headwinds, and our hundreds of days (including about 8 in Wyoming) say you are wrong. If you know of any VHB-Solar panel failures, I and every viewer of this video would really like to hear about it.
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This is the most insane idea anyone has ever come up with, it won't hold to a rubber roof and when that panel goes airborne at 60MPH your going to kill someone!! I have been installing panels on RV's for the last 15 years and I would not use that crap to hold down a zip tie!
I totally agree. This attachment method should never be used with a rubber type, or rolled-on RV roof. Only on a hard, firmly attached surface like fiberglass or painted aluminum.
That's why you aren't an engineer. Look at how airplanes are held together. 90 percent of the strength is adhesives and velcro
A couple of things..first of all your NOT supporting any weight as the weight of the panel is resting on the roof, so the tape is only needed to prevent movement..by what?....well, wind shear either from wind or by driving...need to calculate the wind shear going 80 MPH and then see if it can hold up.
Thanks @johnnyzee383 for the comment. I think you are right, it is mainly wind shear and I did calculate it (at 100mph! See 4:00 to 6:30 in the video) and concluded it is well below the shear strength of the VHB tape. As some commenters have pointed out, there is also a little bit of tensile force pulling up (thanks to Bernoulli), but wind shear is dominant and both forces are well below the shear strength and tensile strength of the VHB.
@@sagebrushers8497 Thanks to your video I did the same thing with my panel...easy peasy and unless we get a hurricane its all good!
No its danger... The panel its dangerous for another driver if panel in driving loss and hit another car ... Screen only nice amd secure 😮.... Thenks for video amd sorry for my englisy
Your right -