help please with heat and adhesive problem?

[Gavin MacMillan]

Did they fall of due to expansion? Dibond has a very low amount on expansion/contraction and I would have thought that the dual lock would be fine as it’s on a thick carrier and has a bit of give in the actual velcro. Obviously that’s no help at all, new one on me though!

G

[Glenn Sharp]

what about double sided taping some U shape channel to the back of the di-bond…upside down so it is "n" shaped….fasten same section channel but "U" up over by screwing through the back boards & hook the di-bond on

Much as you have said really but you wouldn’t need to fix through the surface of the di-bond

[Clive Darbon]

Thanks Gavin, unfortunately I wasn’t in there at the time so it’s difficult to say! I used dibond because I thought it would stand up to the heat better than say foamex, which I reckoned would end up warping. That bit I got right. When I attached the dual lock to the back boards I double fixed it by using staples – that bit also worked. The dual lock on the back of the dibond is what has failed, I didn’t want to staple that on as it would spoil the face side, but now I think I’ve got to fix something on more permanent as the heat is too much? That’s what I’m looking for ideas on, unless there is an adhesive that can really stand up to heat?

[Clive Darbon]

That’s the sort of thing Glenn. But won’t the double sided fail in the heat the same as the dual lock adhesive failed?

[Gavin MacMillan]

Did you rough up the back of the dibond? I’m not sure if it’s compatible but I’ve used the app promoter for the vhb tape with dual lock before with no adverse effects.

G

[Glenn Sharp]

quote spookysign:

That’s the sort of thing Glenn. But won’t the double sided fail in the heat the same as the dual lock adhesive failed?

VHB tape should hold no problem I would have thought….much stronger than the adhesive on velcro.

I would check the working temperatures on it first though if the window does get exeptionally hot

[Andy Gorman]

What level of quality of velcro are you using? The good stuff is almost impossible to remove. In fact, I’ve had it rip pieces of foamex away when removed. I know heat can do some wierd things but the really good velcro has a very aggresive adhesive.

Could you fit some small pins through the dibond into the backboard, small enough not to be too noticeable?

[Gavin MacMillan]

Just wandering that as well Andy, is the 3m dual lock not a vhb as well?

G

[Martin Pearson]

3M Dual lock does have a VHB tape on it so I would think the problem is not so much heat but that you didn’t clean the back of the panels before you applied the tape.
Silly question I know but did you remove the plastic backing from the back of the panels before you applied the dual lock?

[Glenn Sharp]

The thing to watch with all tapes is that when they heat up they are likely to shear….meaning that the downward force of the panel could literally pull the front face of the tape downwards & eventually fail.

Is there any way of supporting underneath the di-bond to prevent gravity having an effect

[Bill McMurtry]

What about using some silicone as the adhesive, with double-sided tape to hold it in place while the silicone sets. Silicone withstands heat well.

[Clive Darbon]

Cheers folks, all good ideas. I did remove the backing off the dibond but I probably should have roughed it up a bit to give a better key. But because I was using 3m dual lock (expensive velcro) I knew that it already was a vhb standard adhesive. I reckon some thin panel pins at the bottom could be a great idea as I doubt they would be seen, and would give just a bit more support against the dreaded gravity! Thanks again.

[Martin Pearson]

Just remember VHB tape is only as good as the surface you are sticking it to, proper preparation and cleaning of the surfaces is vital if you want it to stick properly.

[Clive Darbon]

Thanks Martin, a lesson learned I think, though the tape went straight onto the dibond as soon as the backing was taken off so it should have been clean! Will certainly key the surface in future.

[Warren Beard]

I would have thought with VHB tape a flat clean surface would be better, if it was glue I would score the surface.

Am I going to have a future problem if I have not scored my surfaces?

cheers

Warren

[Martin Pearson]

Warren, no you don’t need to score the surface but it doesn’t do any harm to key it a bit. You do however need to make sure it is properly cleaned and don’t assume that it is clean just because you have only just taken off the wrapping. With VHB I always use iso to clean. 3m also do a cleaner and activator for VHB tape that I have from when I bought some of their tape and I always use that as well.

[Warren Beard]

Hi Martin

OK then, I have only used it on a dibond panel stuck on to another panel and cleaned it well with iso after removing the cover sheet.

it sure does stick that stuff 😮

will be using it again soon for some flat cut letters.

cheers

Warren

[Robert Lambie]

I havent grasped the task here yet but regarding VHB tape…

as martin has said…

quote :

VHB tape is only as good as the surface

It is imperative the surface is immaculate. just removing the backing film is not enough. it should be wiped down with iospropinol or meths…
we then score in two directions using a Stanley knife to allow it to key to the surface. once applied i actually warm the panel with a heat gun to allow adhesion to bite. (this part is not stipulated, but i prefer to)

I use a 2 part 3M glue… its great strong stuff…
when i began using it i cut some 2ft high dibond letters and attached the locaters using the 3M glue. one month later 2 letters fell… i complained to the 3M rep. he comes out to inspect the letters… you guessed it… "no scores" i wasnt convinced this was the problem… but after that the letter never came down again, nor has any other in the 6 years or so we have used it.

[Gavin MacMillan]

We use a scouring pad, not as deep as the stanley scores but never had any problems…. actually we did once, make sure there not the really nice soft scourers that don’t mark pots… they also don’t mark dibond!!!

G