Or, in this case, not.
In general, the flexible LED tapes come with a self-adhesive backing tape. You remove the backing from that, and stick the tape to whatever you want. It (apparently) works a treat. However, the LED tape suppliers also want their tape to be used in harsher environments like bathrooms, kitchens, or outside, where there may be more ambient water around. So they’ve taken to encapsulating their LED tape in silicone. This provides both protection from splashes and dampness, and also a degree of physical protection too, without compromising the flexibility or the light output.
My test purchase was of the latter type. And the problem with this stuff is that the silicone both adds weight, and is a devil to adhere to.
To resolve the first issue, the backing tape really needs to be lot stronger than that on the normal tape. In my case it’s apparently branded 3M adhesive tape, but it’s clearly only just borderline strong enough to hold the LED tape in place when it’s stuck upside down without support. The LED tape and adhesive backing tape are pulling away from the cupboard in places. But worse, in other places the LED tape is pulling away from the adhesive backing tape, leaving just that stuck to the cupboard. Silicone is difficult stuff to stick to, and clearly this 3M tape is struggling.
Now, admittedly it’s hot weather at the moment – pushing 30c in my study – but these adhesive tapes are normally rated to 100+c, so I don’t think that’s the root issue here. It’s the weight and the silicone encapsulation that are causing the problems. So, what options do I have?
When I come to do the kitchen I could switch to un-encapsulated LED tape. That would solve the problem. But it’s not going to be as easy to keep clean, and it’s going to be exposed to steam etc. That doesn’t seem like a good solution. So I really need a better approach to mounting the silicone encapsulated LED tape.
My first thought was “better adhesive tape”. There are structural adhesive tapes around (usually called Very High Bond tapes) that can even be used as alternatives to spot welding. They’re not cheap, but I hoped that they might do the job. And there are some mid-range very high strength “professional” double-sided adhesive tapes that are used to make things like advertising signs that might be OK too. So I called a specialist adhesive tape supplier, Tapes Direct, and asked for some technical help. I ended up talking to the owner, and he wasn’t convinced that any of the normal tapes on the market will work well with silicone – not even the VHB stuff at £50 a roll. Kudos to him for not trying to sell me something that wouldn’t work too – proper customer service – I’ll definitely be using him next time I need some specialist tape. But for now it sounds as though adhesive tape is not the answer.
So the other thought is to stick it in place with Silicone sealant. I suspect this is one of those situations where it will be worth paying for a good quality sealant from someone like Dow Corning or Unibond. But the problem with this is that the good quality silicones all cure slowly, developing maximum strength over about 3 days. Which isn’t going to work upside down on a kitchen cupboard.
So the solution is to get some cheap angle or channel, and mount the LED tape onto that, using the silicone, and then mount that onto the kitchen cabinet (with something like screws) once the silicone has cured. You might be able to get away with plastic channel, but my preference is for some aluminium angle; it’s more rigid, so will mount more easily, and isn’t expensive from a wholesaler, even when bought in small quantities.
So later this week I’ll demount the LED tape in my study and build it up into what amounts to a custom light fitting. The trial continues. But of course, this is going to add to the cost. By self-building, I’m currently looking at about £20 a meter for this LED lighting. Adding aluminium angle & quality silicone sealant is going to raise that, perhaps to nearer £30 a meter. It’s still cost-effective, but the differential to something like these, at about £65/m is falling.
On the positive side though, as well as being cheaper, mine are still both brighter and easier to dim!