Foam Tape for solar panels

[Ian_Edwards]

I'm looking for a supplier of 3M 4956 VHB foam tape. It's specified by the manufacturer for fixing solar panels in the marine environment.
The tape is 12mm wide and 6mm thick and comes in 33m rolls.
The main and, so far, the only supplier I can find in the UK is Viking Tapes, and they are out of stock, and stock is not expected to arrive until late February.
I've spoken to the UK agent for the panels, and they say that the 6mm thick tape gives some flexibility and that they use it to successfully fix solar panels to the roofs of campervans and caravans, so it should be good for a yacht. I think that it basically glazing tape.
The width of the tape isn't critical, anywhere between 9mm and 15mm would work, but the 6mm thickness is critical.
I need 10m of tape.
Any ideas about where I might source this tape or a close equivalent?

 

[PaulRainbow]

Methinks you have the thickness wrong Ian, pretty sure it's 1.6mm, not 6mm.

 

[rotrax]

I will fix my two 1 X 1 metre ones onto the pilot house roof with 6mm S/S studs.

 

[ithet]

I used this supplier;

https://www.amazon.co.uk/dp/B004AQOBS2/ref=pe_3187911_185740111_TE_item

Fixed a 60w semi flex panel with 6 pairs of 50mm strips, so only used about half metre. Has held solidly for four years now.

 

[Ian_Edwards]

Methinks you have the thickness wrong Ian, pretty sure it's 1.6mm, not 6mm.

I've checked with the importer, and they are adamant that 6mm is required, and the tape they specify (3M 4956 VHB foam tape) is 6mm thick, they say it gives flexibility and allows airflow under the panel to helps keep it cool. As I said, they use it on camper vans and caravans which could do 60mph, or more, and they say the panels stay put.
The panels I've just taken off were fixed with a sealant, silicon, Sikaflex or CT1, I don't know which (removing the remaining gunge is my primary task when I work on the boat next week), and they were very difficult to remove, so I don't want to go that route again.
There are no holes to bolt them down, and I'm not going to drill holes on a new panel!

 

[Ian_Edwards]

I used this supplier;

https://www.amazon.co.uk/dp/B004AQOBS2/ref=pe_3187911_185740111_TE_item

Fixed a 60w semi flex panel with 6 pairs of 50mm strips, so only used about half meter. Has held solidly for four years now.

What happens is someone steps on the semi flexible panel?
And how thick is the combined tape, or how big is the gap between the panel and the deck?
I've been thinking about using some form of hook and loop system as an alternative.

 

[ithet]

What happens is someone steps on the semi flexible panel?
And how thick is the combined tape, or how big is the gap between the panel and the deck?
I've been thinking about using some form of hook and loop system as an alternative.

The panel is on the hatch garage. It is a fairly stiff one from Photonics Universe. I kept to just 60w so there was then still enough deck room to avoid stepping on the panel although we sometimes catch an edge without problem. We could probably get away with stepping on our panel occasionally but never have. I would say the combined thickness is 3 or 4mm max. I think a small gap under the panel can help cooling.

 

[Spirit (of Glenans)]

I've checked with the importer, and they are adamant that 6mm is required, and the tape they specify (3M 4956 VHB foam tape) is 6mm thick, they say it gives flexibility and allows airflow under the panel to helps keep it cool. As I said, they use it on camper vans and caravans which could do 60mph, or more, and they say the panels stay put.
The panels I've just taken off were fixed with a sealant, silicon, Sikaflex or CT1, I don't know which (removing the remaining gunge is my primary task when I work on the boat next week), and they were very difficult to remove, so I don't want to go that route again.
There are no holes to bolt them down, and I'm not going to drill holes on a new panel!

I've just checked the 3MIreland website and they say it's 1.6mm thick;
https://www.3mireland.ie/3M/en_IE/p/d/b49000229/

Edit: It's available from Digikey Ireland.
3M 4956 VHB tape ireland - Google Search
I've just checked and it's also available from Digikey UK :
Tapes, Adhesives, Materials | Tape | DigiKey

 

[Ian_Edwards]

I've just cross checked with the 3M data sheet and the suppliers website, and both Spirit (of Glenans), and Paul rainbow are correct, it is 1.6mm thick.
There's a typo in on the suppliers website. What was confusing me was the conversation I had with them where they insisted it was 6mm, I guess they were reading their own website.
Back to Google to see if I can find a UK supplier, now I'm searching for the correct tape.
Thanks for the input, I was really going down a "rabbit hole".

 

[Concerto]

If the air gap is only 1.6mm, then water could become trapped due to the miniscus. My solar panel fitted by the previous owner had just laid it on the hatch box and used 4 large s/s screws to fix it. When I lifted it to repaint the decks some years ago I found osmosis. I now have used a small 3mm high plastic box section with one side with self adhesive. A series of strips have been fixed to the back of the panel and the screws were still long enough to be losened to still hold the panel firm. No water can now be held and still allows good ventilation to keep the panel cool.

 

[ean_p]

I'm looking for a supplier of 3M 4956 VHB foam tape. It's specified by the manufacturer for fixing solar panels in the marine environment.
The tape is 12mm wide and 6mm thick and comes in 33m rolls.
The main and, so far, the only supplier I can find in the UK is Viking Tapes, and they are out of stock, and stock is not expected to arrive until late February.
I've spoken to the UK agent for the panels, and they say that the 6mm thick tape gives some flexibility and that they use it to successfully fix solar panels to the roofs of campervans and caravans, so it should be good for a yacht. I think that it basically glazing tape.
The width of the tape isn't critical, anywhere between 9mm and 15mm would work, but the 6mm thickness is critical.
I need 10m of tape.
Any ideas about where I might source this tape or a close equivalent?

Hi Ian
I just ran the concept of fixing solar panels to motorhome roofs etc using an adhesive tape to the forum of probably the largest motorhome forum in the UK. To a man ( and woman) no one had heard of the practice nor did any consider it advisable either though many had used and heard of VHB etc. I know you're intending to use it in a different application but is a lot of what the supplies say ' hype'....?

 

[Daverw]

Difference may be due to panels on motor homes being subject to hurricane force winds nearly every day but would not expect this on our yachts, well hope not. I would still not trust it long term though personally.

 

[CJ13]

The number plates on modern cars are attached using 4’‘ foam tape vertically on each side. Nothing on the horizontal.
Seems to work fairly well!

 

[PaulRainbow]

I've checked with the importer, and they are adamant that 6mm is required, and the tape they specify (3M 4956 VHB foam tape) is 6mm thick, they say it gives flexibility

Two alarms are going off in my head.

1) They should know it's 1.6mm, not 6mm
2) You do not want any flexibility, if the panels flex they will not last long. They are semi-flexible to allow fitting to slightly curved surfaces, once in place they should not flex.

and allows airflow under the panel to helps keep it cool.

I think this is utter nonsense. The concept of needing a 1.6mm air gap for cooling is nuts. You'd need to put the tape all the around the panel, so there is no air gap, as such.

The panels I've just taken off were fixed with a sealant, silicon, Sikaflex or CT1, I don't know which (removing the remaining gunge is my primary task when I work on the boat next week), and they were very difficult to remove, so I don't want to go that route again.
There are no holes to bolt them down, and I'm not going to drill holes on a new panel!

CT1 or OB1 works well, just put good bead all the way around the panel and a few squiggly lines in the middle, doesn't need to be entirely covered. Yes, they will take some shifting when they need replacing, depending on how much adhesive you use. But, the panels will be well supported and will not flex.

Screws are also another good solution, one in each corner and one at around 18" intervals between the corners. There are no issues with drilling new panels, there is a wide enough border around the edge of the panel to do this and it should not affect the warranty, if it does, buy from a better supplier.

 

[Ningaloo]

I also looked into using this tape to attach two 120W panels and even bought the tape. When it came to fitting, mastic seemed much simpler and avoided the issue of sealing the edges to stop water getting underneath.
Final result was very satisfactory.
I was going to use tape as I thought it might be easier to remove the panel without destroying it, but I bought good quality panels which should last longer than my ability to sail this boat!